WorldWideScience

Sample records for biological evolution

  1. Evolution of biological complexity

    OpenAIRE

    Adami, Christoph; Ofria, Charles; Collier, Travis C.

    2000-01-01

    In order to make a case for or against a trend in the evolution of complexity in biological evolution, complexity needs to be both rigorously defined and measurable. A recent information-theoretic (but intuitively evident) definition identifies genomic complexity with the amount of information a sequence stores about its environment. We investigate the evolution of genomic complexity in populations of digital organisms and monitor in detail the evolutionary transitions that increase complexit...

  2. Biological Evolution and Statistical Physics

    OpenAIRE

    Drossel, Barbara

    2001-01-01

    This review is an introduction to theoretical models and mathematical calculations for biological evolution, aimed at physicists. The methods in the field are naturally very similar to those used in statistical physics, although the majority of publications appeared in biology journals. The review has three parts, which can be read independently. The first part deals with evolution in fitness landscapes and includes Fisher's theorem, adaptive walks, quasispecies models, effects of finite popu...

  3. Evolution, Entropy, & Biological Information

    Science.gov (United States)

    Peterson, Jacob

    2014-01-01

    A logical question to be expected from students: "How could life develop, that is, change, evolve from simple, primitive organisms into the complex forms existing today, while at the same time there is a generally observed decline and disorganization--the second law of thermodynamics?" The explanations in biology textbooks relied upon by…

  4. Evolution of biological information.

    Science.gov (United States)

    Schneider, T D

    2000-07-15

    How do genetic systems gain information by evolutionary processes? Answering this question precisely requires a robust, quantitative measure of information. Fortunately, 50 years ago Claude Shannon defined information as a decrease in the uncertainty of a receiver. For molecular systems, uncertainty is closely related to entropy and hence has clear connections to the Second Law of Thermodynamics. These aspects of information theory have allowed the development of a straightforward and practical method of measuring information in genetic control systems. Here this method is used to observe information gain in the binding sites for an artificial 'protein' in a computer simulation of evolution. The simulation begins with zero information and, as in naturally occurring genetic systems, the information measured in the fully evolved binding sites is close to that needed to locate the sites in the genome. The transition is rapid, demonstrating that information gain can occur by punctuated equilibrium. PMID:10908337

  5. Student Teachers' Approaches to Teaching Biological Evolution

    Science.gov (United States)

    Borgerding, Lisa A.; Klein, Vanessa A.; Ghosh, Rajlakshmi; Eibel, Albert

    2015-01-01

    Evolution is fundamental to biology and scientific literacy, but teaching high school evolution is often difficult. Evolution teachers face several challenges including limited content knowledge, personal conflicts with evolution, expectations of resistance, concerns about students' conflicts with religion, and curricular constraints. Evolution…

  6. ATTITUDES OF BIOLOGY TEACHERS ON TEACHING EVOLUTION OF BIOLOGICAL

    OpenAIRE

    Q. R. Almeida; Alexandre, M.; G. S. Oliveira

    2014-01-01

    This research aimed to determine the attitudes of teachers and high school biology in public schools in Cuiabá about the theory of biological evolution, characterizing its proximity to biological evolution and its opposite perspective to the presence of this theory in science curriculum. Data collection was conducted through a questionnaire-type Likert scale of 4 points, descriptive analyzes were made, represented by absolute data, with the aid of Excel 2010. The results show that the theory ...

  7. A comparison of biological and cultural evolution

    Indian Academy of Sciences (India)

    Petter Portin

    2015-03-01

    This review begins with a definition of biological evolution and a description of its general principles. This is followed by a presentation of the biological basis of culture, specifically the concept of social selection. Further, conditions for cultural evolution are proposed, including a suggestion for language being the cultural replicator corresponding to the concept of the gene in biological evolution. Principles of cultural evolution are put forward and compared to the principles of biological evolution. Special emphasis is laid on the principle of selection in cultural evolution, including presentation of the concept of cultural fitness. The importance of language as a necessary condition for cultural evolution is stressed. Subsequently, prime differences between biological and cultural evolution are presented, followed by a discussion on interaction of our genome and our culture. The review aims at contributing to the present discussion concerning the modern development of the general theory of evolution, for example by giving a tentative formulation of the necessary and sufficient conditions for cultural evolution, and proposing that human creativity and mind reading or theory of mind are motors specific for it. The paper ends with the notion of the still ongoing coevolution of genes and culture.

  8. ATTITUDES OF BIOLOGY TEACHERS ON TEACHING EVOLUTION OF BIOLOGICAL

    Directory of Open Access Journals (Sweden)

    Q. R. Almeida

    2015-06-01

    Full Text Available This research aimed to determine the attitudes of teachers and high school biology in public schools in Cuiabá about the theory of biological evolution, characterizing its proximity to biological evolution and its opposite perspective to the presence of this theory in science curriculum. Data collection was conducted through a questionnaire-type Likert scale of 4 points, descriptive analyzes were made, represented by absolute data, with the aid of Excel 2010. The results show that the theory of biological evolution is highly accepted by the teachers, even considering religious people or people of faith. Furthermore, they indicate that they do not feel prepared to teach and know how few strategies to encourage dialogue between these beliefs and concepts of biological evolution bases.

  9. ATTITUDES OF BIOLOGY TEACHERS ON TEACHING EVOLUTION OF BIOLOGICAL

    Directory of Open Access Journals (Sweden)

    Q. R. Almeida

    2014-07-01

    Full Text Available This research aimed to determine the attitudes of teachers and high school biology in public schools in Cuiabá about the theory of biological evolution, characterizing its proximity to biological evolution and its opposite perspective to the presence of this theory in science curriculum. Data collection was conducted through a questionnaire-type Likert scale of 4 points, descriptive analyzes were made, represented by absolute data, with the aid of Excel 2010. The results show that the theory of biological evolution is highly accepted by the teachers, even considering religious people or people of faith. Furthermore, they indicate that they do not feel prepared to teach and know how few strategies to encourage dialogue between these beliefs and concepts of biological evolution bases.

  10. Teaching Biological Evolution to Singapore's Teachers.

    Science.gov (United States)

    Lee, Yew-Jin; Yeoh, Oon-Chye

    1998-01-01

    Finds that only half of practicing science teachers and a third of pre-service teachers surveyed in Singapore agreed with statements that biological evolution has a valid scientific basis. (Contains 12 references.) (WRM)

  11. Student Teachers' Approaches to Teaching Biological Evolution

    Science.gov (United States)

    Borgerding, Lisa A.; Klein, Vanessa A.; Ghosh, Rajlakshmi; Eibel, Albert

    2015-06-01

    Evolution is fundamental to biology and scientific literacy, but teaching high school evolution is often difficult. Evolution teachers face several challenges including limited content knowledge, personal conflicts with evolution, expectations of resistance, concerns about students' conflicts with religion, and curricular constraints. Evolution teaching can be particularly challenging for student teachers who are just beginning to gain pedagogical knowledge and pedagogical content knowledge related to evolution teaching and who seek approval from university supervisors and cooperating teachers. Science teacher educators need to know how to best support student teachers as they broach the sometimes daunting task of teaching evolution within student teaching placements. This multiple case study report documents how three student teachers approached evolution instruction and what influenced their approaches. Data sources included student teacher interviews, field note observations for 4-5 days of evolution instruction, and evolution instructional artifacts. Data were analyzed using grounded theory approaches to develop individual cases and a cross-case analysis. Seven influences (state exams and standards, cooperating teacher, ideas about teaching and learning, concerns about evolution controversy, personal commitment to evolution, knowledge and preparation for teaching evolution, and own evolution learning experiences) were identified and compared across cases. Implications for science teacher preparation and future research are provided.

  12. Diversity of Students' Beliefs about Biological Evolution

    Science.gov (United States)

    Clores, Michael A.; Limjap, Auxencia A.

    2006-01-01

    The purpose of this study was to determine the beliefs about biological evolution held by college freshman students in one Catholic university in the Philippines. After 4 weeks of constructivist-inspired instruction, interviews and journal entries revealed that the students have diverse beliefs about the theory of evolution. They posited…

  13. Quantum mechanical formalism for biological evolution

    OpenAIRE

    Bianconi, Ginestra; Rahmede, Christoph

    2010-01-01

    We study the evolution of sexual and asexual populations in general fitness landscapes. We find deep relations between the mathematics of biological evolution and the formalism of quantum mechanics. We give the general structure of the evolution of populations which is in general an off-equilibrium process that can be expressed by path integrals over phylogenies. These phylogenies are sums of linear lineages for asexual populations. For sexual populations instead, each lineage is a tree of br...

  14. Evolution, Interactions, and Biological Networks

    OpenAIRE

    Weitz, Joshua S.; Benfey, Philip N.; Wingreen, Ned S.

    2007-01-01

    Shifting the perspective of the questions we ask will ensure that network theory continues to excite the network theorists, but more importantly, that it remains vital to progress in biological research.

  15. Biology Professors' and Teachers' Positions Regarding Biological Evolution and Evolution Education in a Middle Eastern Society

    Science.gov (United States)

    BouJaoude, Saouma; Asghar, Anila; Wiles, Jason R.; Jaber, Lama; Sarieddine, Diana; Alters, Brian

    2011-01-01

    This study investigated three questions: (1) What are Lebanese secondary school (Grade 9-12) biology teachers' and university biology professors' positions regarding biological evolution?, (2) How do participants' religious affiliations relate to their positions about evolutionary science?, and (3) What are participants' positions regarding…

  16. Worldviews and evolution in the biology classroom

    NARCIS (Netherlands)

    Schilders, M.; Sloep, P.; Peled, E.; Boersma, K.T.

    2009-01-01

    This study examined what worldviews are present among Dutch students and teachers and how the students cope with scientific knowledge acquired in the biology classroom. Furthermore, we investigated what learning and teaching strategies teachers adopt when they teach about evolution and worldviews. F

  17. Quantum mechanics formalism for biological evolution

    International Nuclear Information System (INIS)

    Highlights: ► Biological evolution is an off-equilibrium process described by path integrals over phylogenies. ► The phylogenies are sums of linear lineages for asexual populations. ► For sexual populations, each lineage is a tree and the path integral is given by a sum over these trees. ► Quantum statistics describe the stationary state of biological populations in simple cases. - Abstract: We study the evolution of sexual and asexual populations in fitness landscapes compatible with epistatic interactions. We find intriguing relations between the mathematics of biological evolution and quantum mechanics formalism. We give the general structure of the evolution of sexual and asexual populations which is in general an off-equilibrium process that can be expressed by path integrals over phylogenies. These phylogenies are the sum of linear lineages for asexual populations. For sexual populations, instead, each lineage is a tree of branching ratio two and the path integral describing the evolving population is given by a sum over these trees. Finally we show that the Bose–Einstein and the Fermi–Dirac distributions describe the stationary state of biological populations in simple cases.

  18. Biological evolution in a multidimensional fitness landscape.

    Science.gov (United States)

    Saakian, David B; Kirakosyan, Zara; Hu, Chin-Kun

    2012-09-01

    We considered a multiblock molecular model of biological evolution, in which fitness is a function of the mean types of alleles located at different parts (blocks) of the genome. We formulated an infinite population model with selection and mutation, and calculated the mean fitness. For the case of recombination, we formulated a model with a multidimensional fitness landscape (the dimension of the space is equal to the number of blocks) and derived a theorem about the dynamics of initially narrow distribution. We also considered the case of lethal mutations. We also formulated the finite population version of the model in the case of lethal mutations. Our models, derived for the virus evolution, are interesting also for the statistical mechanics and the Hamilton-Jacobi equation as well. PMID:23030957

  19. Modeling Co-evolution of Speech and Biology.

    Science.gov (United States)

    de Boer, Bart

    2016-04-01

    Two computer simulations are investigated that model interaction of cultural evolution of language and biological evolution of adaptations to language. Both are agent-based models in which a population of agents imitates each other using realistic vowels. The agents evolve under selective pressure for good imitation. In one model, the evolution of the vocal tract is modeled; in the other, a cognitive mechanism for perceiving speech accurately is modeled. In both cases, biological adaptations to using and learning speech evolve, even though the system of speech sounds itself changes at a more rapid time scale than biological evolution. However, the fact that the available acoustic space is used maximally (a self-organized result of cultural evolution) is constant, and therefore biological evolution does have a stable target. This work shows that when cultural and biological traits are continuous, their co-evolution may lead to cognitive adaptations that are strong enough to detect empirically. PMID:26936622

  20. On Quantum Effects in a Theory of Biological Evolution

    OpenAIRE

    Martin-Delgado M.A.

    2012-01-01

    We construct a descriptive toy model that considers quantum effects on biological evolution starting from Chaitin's classical framework. There are smart evolution scenarios in which a quantum world is as favorable as classical worlds for evolution to take place. However, in more natural scenarios, the rate of evolution depends on the degree of entanglement present in quantum organisms with respect to classical organisms. If the entanglement is maximal, classical evolution turns out to be more...

  1. A systematic classification of student misconceptions in biological evolution

    OpenAIRE

    Yasri, Pratchayapong

    2014-01-01

    The paper considers student understandings of particular aspects of biological evolution from the perspective of misconceptions. Although lists of misconceptions and possible categories have been proposed in educational research studies, individual misconceptions have not been categorised systematically. This paper therefore explores student misconceptions in biological evolution in greater detail. It synthesises existing categorisation schemes for misconceptions and categorise each misconcep...

  2. Natural evidence for chemical and early biological evolution

    Science.gov (United States)

    Kvenvolden, K. A.

    1974-01-01

    Oparin (1924) and Haldane (1929) have independently hypothesized that life arose under reducing conditions through an evolutionary sequence of events involving increasingly complex organic substances. The natural evidence for this hypothesis of chemical evolution is considered, giving particular attention to tangible samples which have been chemically analyzed in earth-bound laboratories. It is found that meteorites provide naturally occurring evidence in support of chemical evolution, but not of biological evolution. Studies on the early Precambrian Swaziland Sequence and the Bulawayan System of southern Africa provide evidence for very early biological evolution.

  3. Directed Evolution: An Evolving and Enabling Synthetic Biology Tool

    OpenAIRE

    Cobb, Ryan E.; Si, Tong; Zhao, Huimin

    2012-01-01

    Synthetic biology, with its goal of designing biological entities for wide-ranging purposes, remains a field of intensive research interest. However, the vast complexity of biological systems has heretofore rendered rational design prohibitively difficult. As a result, directed evolution remains a valuable tool for synthetic biology, enabling the identification of desired functionalities from large libraries of variants. This review highlights the most recent advances in the use of directed e...

  4. Evolution of biological interaction networks: from models to real data

    OpenAIRE

    Sun, Mark GF; Kim, Philip M.

    2011-01-01

    We are beginning to uncover common mechanisms leading to the evolution of biological networks. The driving force behind these advances is the increasing availability of comparative data in several species.

  5. The phenomenon of biological evolution: 19th century misconception

    OpenAIRE

    Balciunas, Dalius

    2009-01-01

    Scientists still think that biological evolution is driven by the process named natural selection. Perhaps this 19th century notion was indeed a revolutionary idea at the time when it has been introduced. However, now it seems that natural selection hypothesis most probably is wrong. It does not explain, above all, why biological organization arise in the course of evolution. I show, on a rather abstract level of consideration, that exists another explanation why this intriguing phenomenon -...

  6. Muslim Egyptian and Lebanese Students' Conceptions of Biological Evolution

    Science.gov (United States)

    BouJaoude, Saouma; Wiles, Jason R.; Asghar, Anila; Alters, Brian

    2011-01-01

    In this study, we investigated distinctions among the diversity of religious traditions represented by Lebanese and Egyptian Muslim high school students regarding their understanding and acceptance of biological evolution and how they relate the science to their religious beliefs. We explored secondary students' conceptions of evolution among…

  7. Entropy, biological evolution and the psychological arrow of time

    CERN Document Server

    Heinrich, Torsten; Päs, Heinrich

    2014-01-01

    We argue that in Universes where future and past differ only by the entropy content a psychological arrow of time pointing in the direction of entropy increase can arise from natural selection in biological evolution. We show that this effect can be demonstrated in very simple toy computer simulations of evolution in an entropy increasing or decreasing environment.

  8. On the transition period from chemical to biological evolution

    International Nuclear Information System (INIS)

    We discuss the consequences of the hypothesis that biological evolution was contemporary with an important event in chemical evolution, namely, the induction of a small chiral bias by the electroweak neutral interaction, amplified by the Salam enhancement factor, which we discuss in terms of familiar crystallographic terms. (author). 18 refs, 3 tabs

  9. The Biology and Evolution of Music: A Comparative Perspective

    Science.gov (United States)

    Fitch, W. Tecumseh

    2006-01-01

    Studies of the biology of music (as of language) are highly interdisciplinary and demand the integration of diverse strands of evidence. In this paper, I present a comparative perspective on the biology and evolution of music, stressing the value of comparisons both with human language, and with those animal communication systems traditionally…

  10. Mass extinctions vs. uniformitarianism in biological evolution

    Energy Technology Data Exchange (ETDEWEB)

    Bak, P.; Paczuski, M.

    1995-12-31

    It is usually believed that Darwin`s theory leads to a smooth gradual evolution, so that mass extinctions must be caused by external shocks. However, it has recently been argued that mass extinctions arise from the intrinsic dynamics of Darwinian evolution. Species become extinct when swept by intermittent avalanches propagating through the global ecology. These ideas are made concrete through studies of simple mathematical models of co-evolving species. The models exhibit self-organized criticality and describe some general features of the extinction pattern in the fossil record.

  11. Student Acquisition of Biological Evolution-Related Misconceptions: The Role of Public High School Introductory Biology Teachers

    Science.gov (United States)

    Yates, Tony Brett

    2011-01-01

    In order to eliminate student misconceptions concerning biological evolution, it is important to identify their sources. The purposes of this study were to: (a) identify biological evolution-related misconceptions held by Oklahoma public high school Biology I teachers; (b) identify biological evolution-related misconceptions held by Oklahoma…

  12. Directed evolution and synthetic biology applications to microbial systems.

    Science.gov (United States)

    Bassalo, Marcelo C; Liu, Rongming; Gill, Ryan T

    2016-06-01

    Biotechnology applications require engineering complex multi-genic traits. The lack of knowledge on the genetic basis of complex phenotypes restricts our ability to rationally engineer them. However, complex phenotypes can be engineered at the systems level, utilizing directed evolution strategies that drive whole biological systems toward desired phenotypes without requiring prior knowledge of the genetic basis of the targeted trait. Recent developments in the synthetic biology field accelerates the directed evolution cycle, facilitating engineering of increasingly complex traits in biological systems. In this review, we summarize some of the most recent advances in directed evolution and synthetic biology that allows engineering of complex traits in microbial systems. Then, we discuss applications that can be achieved through engineering at the systems level. PMID:27054950

  13. Selection platforms for directed evolution in synthetic biology.

    Science.gov (United States)

    Tizei, Pedro A G; Csibra, Eszter; Torres, Leticia; Pinheiro, Vitor B

    2016-08-15

    Life on Earth is incredibly diverse. Yet, underneath that diversity, there are a number of constants and highly conserved processes: all life is based on DNA and RNA; the genetic code is universal; biology is limited to a small subset of potential chemistries. A vast amount of knowledge has been accrued through describing and characterizing enzymes, biological processes and organisms. Nevertheless, much remains to be understood about the natural world. One of the goals in Synthetic Biology is to recapitulate biological complexity from simple systems made from biological molecules-gaining a deeper understanding of life in the process. Directed evolution is a powerful tool in Synthetic Biology, able to bypass gaps in knowledge and capable of engineering even the most highly conserved biological processes. It encompasses a range of methodologies to create variation in a population and to select individual variants with the desired function-be it a ligand, enzyme, pathway or even whole organisms. Here, we present some of the basic frameworks that underpin all evolution platforms and review some of the recent contributions from directed evolution to synthetic biology, in particular methods that have been used to engineer the Central Dogma and the genetic code. PMID:27528765

  14. Self-organized Critical Model Of Biological Evolution

    OpenAIRE

    Chau, H. F.; Mak, L; Kwok, P. K.

    1994-01-01

    A punctuated equilibrium model of biological evolution with relative fitness between different species being the fundamental driving force of evolution is introduced. Mutation is modeled as a fitness updating cellular automaton process where the change in fitness after mutation follows a Gaussian distribution with mean $x>0$ and standard deviation $\\sigma$. Scaling behaviors are observed in our numerical simulation, indicating that the model is self-organized critical. Besides, the numerical ...

  15. Evolution in invasive plants: implications for biological control

    OpenAIRE

    Müller-Schärer, Heinz; Schaffner, Urs; Steinger, Thomas

    2005-01-01

    Evidence is increasing that invasive plants can undergo rapid adaptive evolution during the process of range expansion. Here, we argue that evolutionary change during invasions will also affect plant–antagonist inter-actions and, thus, will have important implications for biological control programmes targeted at invasive plants. We explore how altered selection in the new range might influence the evolution of plant defence (resistance and tolerance) and life history. The degree to which suc...

  16. Review, Intelligence and Development of Rare Earths during Biological Evolution

    Institute of Scientific and Technical Information of China (English)

    Qiu Guanming; Li Wei; Zhang Ming; Li Zhe; Yan Changhao; Li Yourong; Ding Guohui

    2004-01-01

    The relationship between organism and rare earth elements (REE) viewed from evolution was discussed.Some metal ions play key roles in biological functions, however, as the illustration in this article shows, with powerful affinities for oxygen and similar radius, REE can display equally or even more important functions in terms of its biological functions. These attractive characteristics have called more public attention and lead to many applications in agriculture, medicine fields, etc. Furthermore, the article employed the concept of entropy to discuss the dosage effect of REE on organism and the possibility whether REE can become a portion of organism during the evolution.

  17. Without it no music: cognition, biology and evolution of musicality

    OpenAIRE

    Honing, H.; Cate, ten, J.M.; Peretz, I; Trehub, S.E.

    2015-01-01

    Musicality can be defined as a natural, spontaneously developing trait based on and constrained by biology and cognition. Music, by contrast, can be defined as a social and cultural construct based on that very musicality. One critical challenge is to delineate the constituent elements of musicality. What biological and cognitive mechanisms are essential for perceiving, appreciating and making music? Progress in understanding the evolution of music cognition depends upon adequate characteriza...

  18. Archaea: Evolution, Physiology, and Molecular Biology

    DEFF Research Database (Denmark)

    Introduced by Crafoord Prize winner Carl Woese, this volume combines reviews of the major developments in archaeal research over the past 10-15 years with more specialized articles dealing with important recent breakthroughs. Drawing on major themes presented at the June 2005 meeting held in Munich...... to honor the archaea pioneers Wolfram Zillig and Karl O. Stetter, the book provides a thorough survey of the field from its controversial beginnings to its ongoing expansion to include aspects of eukaryotic biology. The editors have assembled articles from the premier researchers in this rapidly...... burgeoning field, including an account by Carl Woese of his original discovery of the Archaea (until 1990 termed archaebacteria) and the initially mixed reactions of the scientific community. The review chapters and specialized articles address the emerging significance of the Archaea within a broader...

  19. The modern theory of biological evolution: an expanded synthesis.

    Science.gov (United States)

    Kutschera, Ulrich; Niklas, Karl J

    2004-06-01

    In 1858, two naturalists, Charles Darwin and Alfred Russel Wallace, independently proposed natural selection as the basic mechanism responsible for the origin of new phenotypic variants and, ultimately, new species. A large body of evidence for this hypothesis was published in Darwin's Origin of Species one year later, the appearance of which provoked other leading scientists like August Weismann to adopt and amplify Darwin's perspective. Weismann's neo-Darwinian theory of evolution was further elaborated, most notably in a series of books by Theodosius Dobzhansky, Ernst Mayr, Julian Huxley and others. In this article we first summarize the history of life on Earth and provide recent evidence demonstrating that Darwin's dilemma (the apparent missing Precambrian record of life) has been resolved. Next, the historical development and structure of the "modern synthesis" is described within the context of the following topics: paleobiology and rates of evolution, mass extinctions and species selection, macroevolution and punctuated equilibrium, sexual reproduction and recombination, sexual selection and altruism, endosymbiosis and eukaryotic cell evolution, evolutionary developmental biology, phenotypic plasticity, epigenetic inheritance and molecular evolution, experimental bacterial evolution, and computer simulations (in silico evolution of digital organisms). In addition, we discuss the expansion of the modern synthesis, embracing all branches of scientific disciplines. It is concluded that the basic tenets of the synthetic theory have survived, but in modified form. These sub-theories require continued elaboration, particularly in light of molecular biology, to answer open-ended questions concerning the mechanisms of evolution in all five kingdoms of life. PMID:15241603

  20. The modern theory of biological evolution: an expanded synthesis

    Science.gov (United States)

    Kutschera, Ulrich; Niklas, Karl J.

    In 1858, two naturalists, Charles Darwin and Alfred Russel Wallace, independently proposed natural selection as the basic mechanism responsible for the origin of new phenotypic variants and, ultimately, new species. A large body of evidence for this hypothesis was published in Darwin's Origin of Species one year later, the appearance of which provoked other leading scientists like August Weismann to adopt and amplify Darwin's perspective. Weismann's neo-Darwinian theory of evolution was further elaborated, most notably in a series of books by Theodosius Dobzhansky, Ernst Mayr, Julian Huxley and others. In this article we first summarize the history of life on Earth and provide recent evidence demonstrating that Darwin's dilemma (the apparent missing Precambrian record of life) has been resolved. Next, the historical development and structure of the ``modern synthesis'' is described within the context of the following topics: paleobiology and rates of evolution, mass extinctions and species selection, macroevolution and punctuated equilibrium, sexual reproduction and recombination, sexual selection and altruism, endosymbiosis and eukaryotic cell evolution, evolutionary developmental biology, phenotypic plasticity, epigenetic inheritance and molecular evolution, experimental bacterial evolution, and computer simulations (in silico evolution of digital organisms). In addition, we discuss the expansion of the modern synthesis, embracing all branches of scientific disciplines. It is concluded that the basic tenets of the synthetic theory have survived, but in modified form. These sub-theories require continued elaboration, particularly in light of molecular biology, to answer open-ended questions concerning the mechanisms of evolution in all five kingdoms of life.

  1. The Effectiveness of an Online Curriculum on High School Students' Understanding of Biological Evolution

    Science.gov (United States)

    Marsteller, Robert B.; Bodzin, Alec M.

    2015-01-01

    An online curriculum about biological evolution was designed to promote increased student content knowledge and evidentiary reasoning. A feasibility study was conducted with 77 rural high school biology students who learned with the online biological evolution unit. Data sources included the Biological Evolution Assessment Measure (BEAM), an…

  2. Factors Potentially Influencing Student Acceptance of Biological Evolution

    Science.gov (United States)

    Wiles, Jason R.

    This investigation explored scientific, religious, and otherwise nonscientific factors that may influence student acceptance of biological evolution and related concepts, how students perceived these factors to have influenced their levels of acceptance of evolution and changes therein, and what patterns arose among students' articulations of how their levels of acceptance of evolution may have changed. This exploration also measured the extent to which students' levels of acceptance changed following a treatment designed to address factors identified as potentially affecting student acceptance of evolution. Acceptance of evolution was measured using the MATE instrument (Rutledge and Warden, 1999; Rutledge and Sadler, 2007) among participants enrolled in a secondary-level academic program during the summer prior to their final year of high school and as they transitioned to the post-secondary level. Student acceptance of evolution was measured to be significantly higher than pre-treatment levels both immediately following and slightly over one year after treatment. Qualitative data from informal questionnaires, from formal course evaluations, and from semi-structured interviews of students engaged in secondary level education and former students at various stages of post-secondary education confirmed that the suspected factors were perceived by participants to have influenced their levels of acceptance of evolution. Furthermore, participant reports provided insight regarding the relative effects they perceived these factors to have had on their evolution acceptance levels. Additionally, many participants reported that their science teachers in public schools had avoided, omitted, or denigrated evolution during instruction, and several of these students expressed frustration regarding what they perceived to have been a lack of education of an important scientific principle. Finally, no students expressed feelings of being offended by having been taught about

  3. Rapid biological speciation driven by tectonic evolution in New Zealand

    Science.gov (United States)

    Craw, Dave; Upton, Phaedra; Burridge, Christopher P.; Wallis, Graham P.; Waters, Jonathan M.

    2016-02-01

    Collisions between tectonic plates lead to the rise of new mountain ranges that can separate biological populations and ultimately result in new species. However, the identification of links between tectonic mountain-building and biological speciation is confounded by environmental and ecological factors. Thus, there are surprisingly few well-documented examples of direct tectonic controls on terrestrial biological speciation. Here we present examples from New Zealand, where the rapid evolution of 18 species of freshwater fishes has resulted from parallel tectonic landscape evolution. We use numerical models to reconstruct changes in the deep crustal structure and surface drainage catchments of the southern island of New Zealand over the past 25 million years. We show that the island and mountain topography evolved in six principal tectonic zones, which have distinct drainage catchments that separated fish populations. We use new and existing phylogenetic analyses of freshwater fish populations, based on over 1,000 specimens from more than 400 localities, to show that fish genomes can retain evidence of this tectonic landscape development, with a clear correlation between geologic age and extent of DNA sequence divergence. We conclude that landscape evolution has controlled on-going biological diversification over the past 25 million years.

  4. Entropic Sampling and Natural Selection in Biological Evolution

    OpenAIRE

    Choi, M. Y.; Lee, H. Y.; Kim, D.; Park, S H

    1996-01-01

    With a view to connecting random mutation on the molecular level to punctuated equilibrium behavior on the phenotype level, we propose a new model for biological evolution, which incorporates random mutation and natural selection. In this scheme the system evolves continuously into new configurations, yielding non-stationary behavior of the total fitness. Further, both the waiting time distribution of species and the avalanche size distribution display power-law behaviors with exponents close...

  5. Sensitivity to Initial Conditions and Nonextensivity in Biological Evolution

    OpenAIRE

    Tamarit, Francisco A.; Cannas, Sergio A.; Tsallis, Constantino

    1996-01-01

    We consider biological evolution as described within the Bak and Sneppen 1993 model. We exhibit, at the self-organized critical state, a power-law sensitivity to the initial conditions, calculate the associated exponent, and relate it to the recently introduced nonextensive thermostatistics. The scenario which here emerges without tuning strongly reminds that of the tuned onset of chaos in say logistic-like onedimensional maps. We also calculate the dynamical exponent z.

  6. Ohio High School Biology Teachers' Views of State Standard for Evolution: Impacts on Practice

    Science.gov (United States)

    Borgerding, Lisa A.

    2012-01-01

    High school biology teachers face many challenges as they teach evolution. State standards for evolution may provide support for sound evolution instruction. This study attempts to build upon previous work by investigating teachers' views of evolution standards and their evolution practices in a state where evolution standards have been…

  7. Exact Conservation Laws and Exclusion Principle of Biological Evolution

    Science.gov (United States)

    Azbel', Mark Ya.

    2003-03-01

    Biological evolution is dynamics of diversity and complexity of living beings from cells to humans. Metabolism, which allows for entropy decrease, and mortality, which allows for natural selection, are its biological must. Their characteristics are known to yield approximate (and rather noisy) universal relations. I conjecture they are accurate for certain ("canonic") fractions of these characteristics. (The conjecture is verified with experimental tests of its counterintuitive predictions). A relation, which is conserved under (invariant to) transformations from one species in its living conditions to another, is a conservation law of biological evolution. Of course, all parameters of such transformations can hardly be comprehensively specified. However, when canonic fractions are additive, the very invariance of the law to an extraordinary wide class of transformations, with no other experimental data, in any given interval of canonic fraction values accurately predicts [1]: either their conservation law is linear, or the population is homogeneous with respect to their values (an "exclusion principle" of their heterogeneity in an otherwise heterogeneous population). To be specific. Metabolism conservation laws (e.g., the dependence of oxygen consumption at rest per heartbeat on the animal mass) are linear. They imply [2] the existence of fundamental biological constants, which are similar to those crucial in physics. Survivability conservation law (the relation between the probabilities to survive to any two given ages) is piecewise linear (with four linear intervals). At the intersections mortality is homogeneous, and its susceptibility to living conditions vanishes. The law predicts that a dominant canonic fraction of mortality in protected populations is reversible for species as different as humans and flies, and may be eliminated. All these predictions agree with experimental data. (For instance, mortality of Swedish females, born in 1916, at 48 years

  8. Teaching biological evolution - internal and external evaluation of learning outcomes

    Directory of Open Access Journals (Sweden)

    Clas Olander

    2012-06-01

    Full Text Available This paper reports from a study where teachers and researchers collaborate on designing and validatingtopic-oriented teaching-learning sequences. In an iterative process, data about learning andteaching biological evolution are generated through continuous cycles of design, teaching, evaluation,and redesign. The study involved 180 Swedish students aged 11 – 16, and the overall learning aim was that the students should be able to use the theory of evolution as a tool when explaining the development of life on earth. The aim of this paper is to validate the students’ learning outcome, estimated as appropriation of scientific ways of reasoning in written answers. The students’ answers of questions are analysed before and after interventions (internal evaluation, and compared with the answers from a national sample (external evaluation. The students in the experimental group did develop their reasoning, and they attained the aim, to a greater extent than a national sample.

  9. Biological evolution and Brazilian students: knowledge and acceptance

    Directory of Open Access Journals (Sweden)

    Graciela da Silva Oliveira

    2015-08-01

    Full Text Available The aim of this study was to verify topics of the biological evolution theory Brazilian students affirm to know and their relation with variables such as sex, age, geographical localization, socioeconomical aspects, religion and science. 2.404 high school students (55.1% girls enrolled in 78 Brazilian schools took part of the research. The data was generated through a questionnaire and analyzed using the software Statistical Package for Social Science (SPSS version 18.0. The results point out that the knowledge of topics about evolution is low among students and influenced by the variables tested, the associations identified happened in a diversified way, and in lower or higher intensity according to the context studied.

  10. Quantum selfish gene (biological evolution in terms of quantum mechanics)

    OpenAIRE

    Ozhigov, Yuri I.

    2013-01-01

    I propose to treat the biological evolution of genoms by means of quantum mechanical tools. We start with the concept of meta- gene, which specifies the "selfish gene" of R.Dawkins. Meta- gene encodes the abstract living unity, which can live relatively independently of the others, and can contain a few real creatures. Each population of living creatures we treat as the wave function on meta- genes, which module squared is the total number of creatures with the given meta-gene, and the phase ...

  11. The Evolution of Biological Complexity in Digital Organisms

    Science.gov (United States)

    Ofria, Charles

    2013-03-01

    When Darwin first proposed his theory of evolution by natural selection, he realized that it had a problem explaining the origins of traits of ``extreme perfection and complication'' such as the vertebrate eye. Critics of Darwin's theory have latched onto this perceived flaw as a proof that Darwinian evolution is impossible. In anticipation of this issue, Darwin described the perfect data needed to understand this process, but lamented that such data are ``scarcely ever possible'' to obtain. In this talk, I will discuss research where we use populations of digital organisms (self-replicating and evolving computer programs) to elucidate the genetic and evolutionary processes by which new, highly-complex traits arise, drawing inspiration directly from Darwin's wistful thinking and hypotheses. During the process of evolution in these fully-transparent computational environments we can measure the incorporation of new information into the genome, a process akin to a natural Maxwell's Demon, and identify the original source of any such information. We show that, as Darwin predicted, much of the information used to encode a complex trait was already in the genome as part of simpler evolved traits, and that many routes must be possible for a new complex trait to have a high probability of successfully evolving. In even more extreme examples of the evolution of complexity, we are now using these same principles to examine the evolutionary dynamics the drive major transitions in evolution; that is transitions to higher-levels of organization, which are some of the most complex evolutionary events to occur in nature. Finally, I will explore some of the implications of this research to other aspects of evolutionary biology and as well as ways that these evolutionary principles can be applied toward solving computational and engineering problems.

  12. Without it no music: cognition, biology and evolution of musicality.

    Science.gov (United States)

    Honing, Henkjan; ten Cate, Carel; Peretz, Isabelle; Trehub, Sandra E

    2015-03-19

    Musicality can be defined as a natural, spontaneously developing trait based on and constrained by biology and cognition. Music, by contrast, can be defined as a social and cultural construct based on that very musicality. One critical challenge is to delineate the constituent elements of musicality. What biological and cognitive mechanisms are essential for perceiving, appreciating and making music? Progress in understanding the evolution of music cognition depends upon adequate characterization of the constituent mechanisms of musicality and the extent to which they are present in non-human species. We argue for the importance of identifying these mechanisms and delineating their functions and developmental course, as well as suggesting effective means of studying them in human and non-human animals. It is virtually impossible to underpin the evolutionary role of musicality as a whole, but a multicomponent perspective on musicality that emphasizes its constituent capacities, development and neural cognitive specificity is an excellent starting point for a research programme aimed at illuminating the origins and evolution of musical behaviour as an autonomous trait. PMID:25646511

  13. "Evo in the News:" Understanding Evolution and Students' Attitudes toward the Relevance of Evolutionary Biology

    Science.gov (United States)

    Infanti, Lynn M.; Wiles, Jason R.

    2014-01-01

    This investigation evaluated the effects of exposure to the "Evo in the News" section of the "Understanding Evolution" website on students' attitudes toward biological evolution in undergraduates in a mixed-majors introductory biology course at Syracuse University. Students' attitudes toward evolution and changes therein were…

  14. An examination of conceptual change in undergraduate biology majors while learning science concepts including biological evolution

    Science.gov (United States)

    McQuaide, Glenn G.

    2006-12-01

    Without adequate understanding of science, we cannot make responsible personal, regional, national, or global decisions about any aspect of life dealing with science. Better understanding how we learn about science can contribute to improving the quality of our educational experiences. Promoting pathways leading to life-long learning and deep understanding in our world should be a goal for all educators. This dissertation project was a phenomenological investigation into undergraduate understanding and acceptance of scientific theories, including biological evolution. Specifically, student descriptions of conceptual change while learning science theory were recorded and analyzed. These qualitative investigations were preceded by a survey that provided a means of selecting students who had a firmer understanding of science theory. Background information and survey data were collected in an undergraduate biology class at a small, Southern Baptist-affiliated liberal arts school located in south central Kentucky. Responses to questions on the MATE (Rutledge and Warden, 1999) instrument were used to screen students for interviews, which investigated the way by which students came to understand and accept scientific theories. This study identifies some ways by which individuals learn complex science theories, including biological evolution. Initial understanding and acceptance often occurs by the conceptual change method described by Posner et al. (1982). Three principle ways by which an individual may reach a level of understanding and acceptance of science theory were documented in this study. They were conceptual change through application of logic and reasoning; conceptual change through modification of religious views; and conceptual change through acceptance of authoritative knowledge. Development of a deeper, richer understanding and acceptance of complex, multi-faceted concepts such as biological evolution occurs in some individuals by means of conceptual

  15. Quantum selfish gene (biological evolution in terms of quantum mechanics)

    CERN Document Server

    Ozhigov, Yuri I

    2014-01-01

    I propose to treat the biological evolution of genoms by means of quantum mechanical tools. We start with the concept of meta- gene, which specifies the "selfish gene" of R.Dawkins. Meta- gene encodes the abstract living unity, which can live relatively independently of the others, and can contain a few real creatures. Each population of living creatures we treat as the wave function on meta- genes, which module squared is the total number of creatures with the given meta-gene, and the phase is the sum of "aspirations" to change the classical states of meta- genes. Each individual life thus becomes one of possible outcomes of the virtual quantum measurement of this function. The evolution of genomes is described by the unitary operator in the space of psi-functions or by Kossovsky-Lindblad equation in the case of open biosystems. This operator contains all the information about specific conditions under which individuals are, and how "aspirations" of their meta- genes may be implemented at the biochemical lev...

  16. Evolution of bow-tie architectures in biology.

    Directory of Open Access Journals (Sweden)

    Tamar Friedlander

    2015-03-01

    Full Text Available Bow-tie or hourglass structure is a common architectural feature found in many biological systems. A bow-tie in a multi-layered structure occurs when intermediate layers have much fewer components than the input and output layers. Examples include metabolism where a handful of building blocks mediate between multiple input nutrients and multiple output biomass components, and signaling networks where information from numerous receptor types passes through a small set of signaling pathways to regulate multiple output genes. Little is known, however, about how bow-tie architectures evolve. Here, we address the evolution of bow-tie architectures using simulations of multi-layered systems evolving to fulfill a given input-output goal. We find that bow-ties spontaneously evolve when the information in the evolutionary goal can be compressed. Mathematically speaking, bow-ties evolve when the rank of the input-output matrix describing the evolutionary goal is deficient. The maximal compression possible (the rank of the goal determines the size of the narrowest part of the network-that is the bow-tie. A further requirement is that a process is active to reduce the number of links in the network, such as product-rule mutations, otherwise a non-bow-tie solution is found in the evolutionary simulations. This offers a mechanism to understand a common architectural principle of biological systems, and a way to quantitate the effective rank of the goals under which they evolved.

  17. Evolution of bow-tie architectures in biology.

    Science.gov (United States)

    Friedlander, Tamar; Mayo, Avraham E; Tlusty, Tsvi; Alon, Uri

    2015-03-01

    Bow-tie or hourglass structure is a common architectural feature found in many biological systems. A bow-tie in a multi-layered structure occurs when intermediate layers have much fewer components than the input and output layers. Examples include metabolism where a handful of building blocks mediate between multiple input nutrients and multiple output biomass components, and signaling networks where information from numerous receptor types passes through a small set of signaling pathways to regulate multiple output genes. Little is known, however, about how bow-tie architectures evolve. Here, we address the evolution of bow-tie architectures using simulations of multi-layered systems evolving to fulfill a given input-output goal. We find that bow-ties spontaneously evolve when the information in the evolutionary goal can be compressed. Mathematically speaking, bow-ties evolve when the rank of the input-output matrix describing the evolutionary goal is deficient. The maximal compression possible (the rank of the goal) determines the size of the narrowest part of the network-that is the bow-tie. A further requirement is that a process is active to reduce the number of links in the network, such as product-rule mutations, otherwise a non-bow-tie solution is found in the evolutionary simulations. This offers a mechanism to understand a common architectural principle of biological systems, and a way to quantitate the effective rank of the goals under which they evolved. PMID:25798588

  18. Beware of Nuts and Bolts: Putting Evolution into the Teaching of Biological Classification

    Science.gov (United States)

    Nickels, Martin K.; Nelson, Craig E.

    2005-01-01

    Biological classification embodies the most fundamental idea in all of biology, especially evolution. The contrast between biological classifications and those of manufactured objects for instance hardware-based collection of screws, nails and bolts, help illustrate the central biological ideas and induce student interest, however, this could be…

  19. On the origin and early evolution of biological catalysis and other studies on chemical evolution

    Science.gov (United States)

    Oro, J.; Lazcano, A.

    1991-01-01

    One of the lines of research in molecular evolution which we have developed for the past three years is related to the experimental and theoretical study of the origin and early evolution of biological catalysis. In an attempt to understand the nature of the first peptidic catalysts and coenzymes, we have achieved the non-enzymatic synthesis of the coenzymes ADPG, GDPG, and CDP-ethanolamine, under conditions considered to have been prevalent on the primitive Earth. We have also accomplished the prebiotic synthesis of histidine, as well as histidyl-histidine, and we have measured the enhancing effects of this catalytic dipeptide on the dephosphorylation of deoxyribonucleotide monophosphates, the hydrolysis of oligo A, and the oligomerization 2', 3' cAMP. We reviewed and further developed the hypothesis that RNA preceded double stranded DNA molecules as a reservoir of cellular genetic information. This led us to undertake the study of extant RNA polymerases in an attempt to discover vestigial sequences preserved from early Archean times. In addition, we continued our studies of on the chemical evolution of organic compounds in the solar system and beyond.

  20. Biology Students' and Teachers' Religious Beliefs and Attitudes towards Theory of Evolution

    Science.gov (United States)

    Ozay Kose, Esra

    2010-01-01

    Evolution has not being well addressed in schools partly because it is a controversial topic in religious views. In the present study, it is explored to what extent Turkish secondary school biology teachers and students accommodate the theory of biological evolution with their religious beliefs. Two-hundred fifty secondary school students and…

  1. Can chimpanzee biology highlight human origin and evolution?

    Science.gov (United States)

    Roffman, Itai; Nevo, Eviatar

    2010-07-01

    The closest living relatives of humans are their chimpanzee/bonobo (Pan) sister species, members of the same subfamily "Homininae". This classification is supported by over 50 years of research in the fields of chimpanzee cultural diversity, language competency, genomics, anatomy, high cognition, psychology, society, self-consciousness and relation to others, tool use/production, as well as Homo level emotions, symbolic competency, memory recollection, complex multifaceted problem-solving capabilities, and interspecies communication. Language competence and symbolism can be continuously bridged from chimpanzee to man. Emotions, intercommunity aggression, body language, gestures, facial expressions, and vocalization of intonations seem to parallel between the sister taxa Homo and Pan. The shared suite of traits between Pan and Homo genus demonstrated in this article integrates old and new information on human-chimpanzee evolution, bilateral informational and cross-cultural exchange, promoting the urgent need for Pan cultures in the wild to be protected, as they are part of the cultural heritage of mankind. Also, we suggest that bonobos, Pan paniscus, based on shared traits with Australopithecus, need to be included in Australopithecine's subgenus, and may even represent living-fossil Australopithecines. Unfolding bonobo and chimpanzee biology highlights our common genetic and cultural evolutionary origins. PMID:23908781

  2. Can Chimpanzee Biology Highlight Human Origin and Evolution?

    Directory of Open Access Journals (Sweden)

    Itai Roffman

    2010-07-01

    Full Text Available The closest living relatives of humans are their chimpanzee/bonobo (Pan sister species, members of the same subfamily “Homininae”. This classification is supported by over 50 years of research in the fields of chimpanzee cultural diversity, language competency, genomics, anatomy, high cognition, psychology, society, self-consciousness and relation to others, tool use/production, as well as Homo level emotions, symbolic competency, memory recollection, complex multifaceted problem-solving capabilities, and interspecies communication. Language competence and symbolism can be continuously bridged from chimpanzee to man. Emotions, intercommunity aggression, body language, gestures, facial expressions, and vocalization of intonations seem to parallel between the sister taxa Homo and Pan. The shared suite of traits between Pan and Homo genus demonstrated in this article integrates old and new information on human–chimpanzee evolution, bilateral informational and cross-cultural exchange, promoting the urgent need for Pan cultures in the wild to be protected, as they are part of the cultural heritage of mankind. Also, we suggest that bonobos, Pan paniscus, based on shared traits with Australopithecus, need to be included in Australopithecine’s subgenus, and may even represent living-fossil Australopithecines. Unfolding bonobo and chimpanzee biology highlights our common genetic and cultural evolutionary origins.

  3. Can Chimpanzee Biology Highlight Human Origin and Evolution?

    Science.gov (United States)

    Roffman, Itai; Nevo, Eviatar

    2010-01-01

    The closest living relatives of humans are their chimpanzee/bonobo (Pan) sister species, members of the same subfamily “Homininae”. This classification is supported by over 50 years of research in the fields of chimpanzee cultural diversity, language competency, genomics, anatomy, high cognition, psychology, society, self-consciousness and relation to others, tool use/production, as well as Homo level emotions, symbolic competency, memory recollection, complex multifaceted problem-solving capabilities, and interspecies communication. Language competence and symbolism can be continuously bridged from chimpanzee to man. Emotions, intercommunity aggression, body language, gestures, facial expressions, and vocalization of intonations seem to parallel between the sister taxa Homo and Pan. The shared suite of traits between Pan and Homo genus demonstrated in this article integrates old and new information on human–chimpanzee evolution, bilateral informational and cross-cultural exchange, promoting the urgent need for Pan cultures in the wild to be protected, as they are part of the cultural heritage of mankind. Also, we suggest that bonobos, Pan paniscus, based on shared traits with Australopithecus, need to be included in Australopithecine’s subgenus, and may even represent living-fossil Australopithecines. Unfolding bonobo and chimpanzee biology highlights our common genetic and cultural evolutionary origins. PMID:23908781

  4. Preparing Biology Teachers to Teach Evolution in a Project-Based Approach

    Science.gov (United States)

    Cook, Kristin; Buck, Gayle; Park Rogers, Meredith

    2012-01-01

    This study investigates a project-based learning (PBL) approach to teaching evolution to inform efforts in teacher preparation. Data analysis of a secondary biology educator teaching evolution through a PBL approach illuminated: (1) active student voice, which allowed students to reflect on their positioning on evolution and consider multiple…

  5. Making the right connections: biological networks in the light of evolution

    OpenAIRE

    Knight, Christopher G.; Pinney, John W

    2009-01-01

    Our understanding of how evolution acts on biological networks remains patchy, as is our knowledge of how that action is best identified, modelled and understood. Starting with network structure and the evolution of protein–protein interaction networks, we briefly survey the ways in which network evolution is being addressed in the fields of systems biology, development and ecology. The approaches highlighted demonstrate a movement away from a focus on network topology towards a more integrat...

  6. Thermodynamic Theory of Biological Evolution and Aging. Experimental Confirmation of Theory

    OpenAIRE

    Gladyshev, Georgi P.

    1999-01-01

    Abstract: The work presents experimental confirmation of the author's thermodynamic theory of the biological evolution and aging of living beings. It shows that using the law of temporal hierarchies and the second law of thermodynamics, it is easy to describe biological evolution (phylogeny) and ontogeny in terms of equilibrium hierarchical thermodynamics. This theory explains many known facts and makes it possible to formulate new practical recommendations in the sphere of medical and biolog...

  7. Learning bias, cultural evolution of language, and the biological evolution of the language faculty.

    Science.gov (United States)

    Smith, Kenny

    2011-04-01

    The biases of individual language learners act to determine the learnability and cultural stability of languages: learners come to the language learning task with biases which make certain linguistic systems easier to acquire than others. These biases are repeatedly applied during the process of language transmission, and consequently should effect the types of languages we see in human populations. Understanding the cultural evolutionary consequences of particular learning biases is therefore central to understanding the link between language learning in individuals and language universals, common structural properties shared by all the world’s languages. This paper reviews a range of models and experimental studies which show that weak biases in individual learners can have strong effects on the structure of socially learned systems such as language, suggesting that strong universal tendencies in language structure do not require us to postulate strong underlying biases or constraints on language learning. Furthermore, understanding the relationship between learner biases and language design has implications for theories of the evolution of those learning biases: models of gene-culture coevolution suggest that, in situations where a cultural dynamic mediates between properties of individual learners and properties of language in this way, biological evolution is unlikely to lead to the emergence of strong constraints on learning. PMID:21615289

  8. Evolution and Personal Religious Belief: Christian University Biology-Related Majors' Search for Reconciliation

    Science.gov (United States)

    Winslow, Mark W.; Staver, John R.; Scharmann, Lawrence C.

    2011-01-01

    The goal of this study was to explore Christian biology-related majors' perceptions of conflicts between evolution and their religious beliefs. This naturalistic study utilized a case study design of 15 undergraduate biology-related majors at or recent biology-related graduates from a mid-western Christian university. The broad sources of data…

  9. Factors which influence Texas biology teachers' decisions to emphasize fundamental concepts of evolution

    Science.gov (United States)

    Bilica, Kimberly Lynn

    The teaching of biological evolution in public science classrooms has been mitigated by a lingering and historic climate of controversy (Skoog, 1984; Skoog, 1979). This controversy has successfully stalled attempts to bring authentic science literacy to the American public (Bybee, 1997). The first encouraging signs of the abatement of this controversy occurred during the early 1990s when several prominent science organizations promoted evolution to its appropriate status as a central and unifying concept in biology (National Science Teachers Association, 1992; National Research Council, 1996; American Association for the Advancement of Science, 1990, 1993). The organizations acknowledged that not only should biological evolution be taught, evolution should stand as one of a select group of essential concepts upon which biology curricula should be built. Bandura's Social Learning theory (Bandura, 1997; Lumpe, Haney, & Czerniak, 2000) and Helms' Model of Identity (Helms, 1998) provide the theoretical basis for this study. Both Bandura and Helms explain the actions of teachers by examining the beliefs and values that influence their decisions. The models distinguish between two types of belief systems: capacity beliefs and context beliefs (Lumpe, et al, 2000; Helms, 1998). Both belief types influence and are influenced by individual actions. In this study, the action to be described is the decision that teachers make about the degree of emphasis on evolution in the classroom. The capacity beliefs that will be examined are teachers' beliefs about their capability to teach evolution. The contextual beliefs in this study are perceptions about students' capabilities to learn evolution, the status of evolution in science, the place of evolution in the biology classroom, the influence of textbooks, time, and community/school values. This study contributes to and extends the knowledge base established by studies of evolution education by exploring the relative amount of

  10. Systems Medicine: Evolution of Systems Biology From Bench To Bedside

    OpenAIRE

    Wang, Rui-Sheng; Maron, Bradley A.; Loscalzo, Joseph

    2015-01-01

    High-throughput experimental techniques for generating genomes, transcriptomes, proteomes, metabolomes, and interactomes have provided unprecedented opportunities to interrogate biological systems and human diseases on a global level. Systems biology integrates the mass of heterogeneous high-throughput data and predictive computational modeling to understand biological functions as system-level properties. Most human diseases are biological states caused by multiple components of perturbed pa...

  11. Beyond directed evolution: Darwinian selection as a tool for synthetic biology

    OpenAIRE

    Porcar, Manuel

    2009-01-01

    Synthetic biology is an engineering approach that seeks to design and construct new biological parts, devices and systems, as well as to re-design existing components. However, rationally designed synthetic circuits may not work as expected due to the context-dependence of biological parts. Darwinian selection, the main mechanism through which evolution works, is a major force in creating biodiversity and may be a powerful tool for synthetic biology. This article reviews selection-based techn...

  12. Sole-Manrubia model of biological evolution: some new insights

    OpenAIRE

    Chowdhury, Debashish; Stauffer, Dietrich

    2002-01-01

    The Sole-Manrubia model of ``macro''-evolution describes the origination, evolution and extinction of species on geological time scales. We report some properties of this model which provide deep insight into this simple model which captures several realistic features.

  13. Biology of the sauropod dinosaurs: the evolution of gigantism

    Science.gov (United States)

    Sander, P Martin; Christian, Andreas; Clauss, Marcus; Fechner, Regina; Gee, Carole T; Griebeler, Eva-Maria; Gunga, Hanns-Christian; Hummel, Jürgen; Mallison, Heinrich; Perry, Steven F; Preuschoft, Holger; Rauhut, Oliver W M; Remes, Kristian; Tütken, Thomas; Wings, Oliver; Witzel, Ulrich

    2011-01-01

    The herbivorous sauropod dinosaurs of the Jurassic and Cretaceous periods were the largest terrestrial animals ever, surpassing the largest herbivorous mammals by an order of magnitude in body mass. Several evolutionary lineages among Sauropoda produced giants with body masses in excess of 50 metric tonnes by conservative estimates. With body mass increase driven by the selective advantages of large body size, animal lineages will increase in body size until they reach the limit determined by the interplay of bauplan, biology, and resource availability. There is no evidence, however, that resource availability and global physicochemical parameters were different enough in the Mesozoic to have led to sauropod gigantism. We review the biology of sauropod dinosaurs in detail and posit that sauropod gigantism was made possible by a specific combination of plesiomorphic characters (phylogenetic heritage) and evolutionary innovations at different levels which triggered a remarkable evolutionary cascade. Of these key innovations, the most important probably was the very long neck, the most conspicuous feature of the sauropod bauplan. Compared to other herbivores, the long neck allowed more efficient food uptake than in other large herbivores by covering a much larger feeding envelope and making food accessible that was out of the reach of other herbivores. Sauropods thus must have been able to take up more energy from their environment than other herbivores. The long neck, in turn, could only evolve because of the small head and the extensive pneumatization of the sauropod axial skeleton, lightening the neck. The small head was possible because food was ingested without mastication. Both mastication and a gastric mill would have limited food uptake rate. Scaling relationships between gastrointestinal tract size and basal metabolic rate (BMR) suggest that sauropods compensated for the lack of particle reduction with long retention times, even at high uptake rates. The

  14. A Powerful Toolkit for Synthetic Biology: Over 3.8 Billion Years of Evolution

    Science.gov (United States)

    Rothschild, Lynn J.

    2010-01-01

    The combination of evolutionary with engineering principles will enhance synthetic biology. Conversely, synthetic biology has the potential to enrich evolutionary biology by explaining why some adaptive space is empty, on Earth or elsewhere. Synthetic biology, the design and construction of artificial biological systems, substitutes bio-engineering for evolution, which is seen as an obstacle. But because evolution has produced the complexity and diversity of life, it provides a proven toolkit of genetic materials and principles available to synthetic biology. Evolution operates on the population level, with the populations composed of unique individuals that are historical entities. The source of genetic novelty includes mutation, gene regulation, sex, symbiosis, and interspecies gene transfer. At a phenotypic level, variation derives from regulatory control, replication and diversification of components, compartmentalization, sexual selection and speciation, among others. Variation is limited by physical constraints such as diffusion, and chemical constraints such as reaction rates and membrane fluidity. While some of these tools of evolution are currently in use in synthetic biology, all ought to be examined for utility. A hybrid approach of synthetic biology coupled with fine-tuning through evolution is suggested

  15. Autocatalysis as the Natural Philosophy Underlying Complexity and Biological Evolution

    Directory of Open Access Journals (Sweden)

    Güngör Gündüz

    2011-06-01

    Full Text Available The importance and different aspects of autocatalysis in evolution was analyzed. The behaviour of autocatalytic reactions mainly the Lotka-Volterra and the Schlögl equations were discussed in terms of phase change, entropy, and their oscillation frequency. The increase of complexity as the general direction of evolution was examined on some patterns in terms of both their entropy and information content. In addition, the relation between stability and functionality, stability and cohesion were discussed. It was concluded that evolution drifts in the direction of increasing complexity as a kind of natural philosophy to counteract the increase of entropy in the universe.

  16. Biological and therapeutic impact of intratumor heterogeneity in cancer evolution.

    Science.gov (United States)

    McGranahan, Nicholas; Swanton, Charles

    2015-01-12

    Precision medicine requires an understanding of cancer genes and mutational processes, as well as an appreciation of the extent to which these are found heterogeneously in cancer cells during tumor evolution. Here, we explore the processes shaping the cancer genome, placing these within the context of tumor evolution and their impact on intratumor heterogeneity and drug development. We review evidence for constraints and contingencies to tumor evolution and highlight the clinical implications of diversity within tumors. We outline the limitations of genome-driven targeted therapies and explore future strategies, including immune and adaptive approaches, to address this therapeutic challenge. PMID:25584892

  17. Cognition and Biological Evolution An Approach from Idealist Philosophy Resolves a Fundamental Paradox

    OpenAIRE

    Randrup, Dr. Axel, Abraham

    2006-01-01

    The basic philosophy of mainstream biology, the philosophy of materialist realism, assumes the existence of a material world independent of human observation and cognition. The scientific study of cognition in the context of biological evolution (CE) has, however, led to the result, that all our thoughts and cognitions, including the assumption of a material world, are dependent on our cognitive apparatus in its present stage of evolution. I think, this result is in contradiction with the mat...

  18. Diploid biological evolution models with general smooth fitness landscapes and recombination.

    Science.gov (United States)

    Saakian, David B; Kirakosyan, Zara; Hu, Chin-Kun

    2008-06-01

    Using a Hamilton-Jacobi equation approach, we obtain analytic equations for steady-state population distributions and mean fitness functions for Crow-Kimura and Eigen-type diploid biological evolution models with general smooth hypergeometric fitness landscapes. Our numerical solutions of diploid biological evolution models confirm the analytic equations obtained. We also study the parallel diploid model for the simple case of recombination and calculate the variance of distribution, which is consistent with numerical results. PMID:18643300

  19. Quantum demon and the problem of the biological evolution rate

    International Nuclear Information System (INIS)

    The possibility of a complicated internal structure of an elementary particle was analyzed. In this case a particle may represent a quantum computer with many degrees of freedom. The evolution process of the genome was considered. The probability of formation of new species by means of random mutations was shown to be negligibly small. This behavior of the genome of an organism might result from the operation of elementary particle quantum computer. Deterministic model of evolution is considered

  20. Science for Survival: The Modern Synthesis of Evolution and the Biological Sciences Curriculum Study

    Science.gov (United States)

    Green, Lisa Anne

    2012-01-01

    In this historical dissertation, I examined the process of curriculum development in the Biological Sciences Curriculum Study (BSCS) in the United States during the period 1959-1963. The presentation of evolution in the high school texts was based on a more robust form of Darwinian evolution which developed during the 1930s and 1940s called…

  1. ''La Grande Galerie de l'Evolution'' of Paris: The only museum in the world entirely devoted to biological evolution

    International Nuclear Information System (INIS)

    The new building called ''Grande Galerie de l'Evolution'' of the national Museum of natural History, in Paris-France, is the first museum in the world exclusively devoted to biological evolution. The Museum is divided in 3 parts (named ''Acts''): The aim of Act 1 is to sensibilize the visitor to the results of 4 billions years of biological evolution. This act shows some examples of biological diversity through few terrestrial and marine environments (deserts, tropical forests, polar habitats, abyssal zones ...). Act 2 is the principal part of the Museum explaining the main processes of evolution. This part shows also the story of life from the first living cells to man. Act 3, the last part offers to visitors a vision of the interactions between man and nature, and of their consequences along millions of years. A special Gallery is entirely devoted to vanished and threatened species, as a nefast consequence of human interaction on biological diversity particularly since the beginning of this century. (Abstract only)

  2. Should the teaching of biological evolution include the origin of life?

    OpenAIRE

    Lazcano, A; Peretó, Juli

    2010-01-01

    The development of mainstream research on the origin of life as an outcome of Darwinian evolution is discussed. It is argued that prebiotic evolution and the origin of life should not be excluded from the syllabus and should be part of classes on biological evolution, and that the transition from non-living to living matter is best understood when seen as part of evolutionary biology. The wide acceptance of evolutionary approaches to the study of the emergence of life in European and Latin Am...

  3. The biology of human sexuality: evolution, ecology and physiology

    OpenAIRE

    PW Bateman; NC Bennett

    2006-01-01

    Many evolutionary biologists argue that human sexual behaviour can be studied in exactly the same way as that of other species. Many sociologists argue that social influences effectively obscure, and are more important than, a reductionist biological approach to human sexual behaviour. Here,we authors attempt to provide a broad introduction to human sexual behaviour from a biological standpoint and to indicate where the ambiguous areas are. We outline the evolutionary selective pressures that...

  4. WWW.cell Biology Education: Evolution Web Sites

    Science.gov (United States)

    Liu, Dennis

    2005-01-01

    The debate over teaching evolution has once again reached a fever pitch in the United States. Earnest nineteenth-century clashes between scientific and religious worldviews have given way to the politically charged arguments of creation science and now intelligent design. The Web site of the National Center for Science Education (NCSE;…

  5. The Effectiveness of an Online Curriculum on High School Students' Understanding of Biological Evolution

    Science.gov (United States)

    Marsteller, Robert B.; Bodzin, Alec M.

    2015-12-01

    An online curriculum about biological evolution was designed to promote increased student content knowledge and evidentiary reasoning. A feasibility study was conducted with 77 rural high school biology students who learned with the online biological evolution unit. Data sources included the Biological Evolution Assessment Measure (BEAM), an analysis of discussion forum posts, and a post-implementation perceptions and attitudes questionnaire. BEAM posttest scores were significantly higher than the pretest scores. However, the findings revealed that the students required additional support to develop evidentiary reasoning. Many students perceived that the Web-based curriculum would have been enhanced by increased immediate interaction and feedback. Students required greater scaffolding to support complex, process-oriented tasks. Implications for designing Web-based science instruction with curriculum materials to support students' acquisition of content knowledge and science process skills in a Web-based setting are discussed.

  6. Women in evolution - highlighting the changing face of evolutionary biology.

    Science.gov (United States)

    Wellenreuther, Maren; Otto, Sarah

    2016-01-01

    The face of science has changed. Women now feature alongside men at the forefront of many fields, and this is particularly true in evolutionary biology. This special issue celebrates the outstanding achievements and contributions of women in evolutionary biology, by highlighting a sample of their research and accomplishments. In addition to original research contributions, this collection of articles contains personal reflections to provide perspective and advice on succeeding as a woman in science. By showcasing the diversity and research excellence of women and drawing on their experiences, we wish to enhance the visibility of female scientists and provide inspiration as well as role models. These are exciting times for evolutionary biology, and the field is richer and stronger for the diversity of voices contributing to the field. PMID:27087836

  7. Without it no music: Cognition, biology, and evolution of musicality

    NARCIS (Netherlands)

    H. Honing; C. ten Cate; I. Peretz; S.E. Trehub

    2015-01-01

    Musicality can be defined as a natural, spontaneously developing trait based on and constrained by biology and cognition. Music, by contrast, can be defined as a social and cultural construct based on that very musicality. One critical challenge is to delineate the constituent elements of musicality

  8. Biology, genome organization and evolution of parvoviruses in marine shrimp

    Science.gov (United States)

    A number of parvoviruses are now know to infect marine shrimp, and these viruses alone or in combination with other viruses have the potential to cause major losses in shrimp aquaculture globally. This review provides a comprehensive overview of the biology, genome organization, gene expression, and...

  9. Darwin's legacy: why biology is not physics, or why evolution has not become a common sense.

    Science.gov (United States)

    Singh, Rama S

    2011-10-01

    Cosmology and evolution together have enabled us to look deep into the past and comprehend evolution-from the big bang to the cosmos, from molecules to humans. Here, I compare the nature of theories in biology and physics and ask why physical theories get accepted by the public without necessarily comprehending them but biological theories do not. Darwin's theory of natural selection, utterly simple in its premises but profound in its consequences, is not accepted widely. Organized religions, and creationists in particularly, have been the major critic of evolution, but not all opposition to evolution comes from organized religions. A great many people, between evolutionary biologists on one hand and creationists on the other, many academics included, who may not be logically opposed to evolution nevertheless do not accept it. This is because the process of and the evidence for evolution are invisible to a nonspecialist, or the theory may look too simple to explain complex traits to some, or because people compare evolution against God and find evolutionary explanations threatening to their beliefs. Considering how evolution affects our lives, including health and the environment to give just two examples, a basic course in evolution should become a required component of all our college and university educational systems. PMID:21942430

  10. Canadian Pre-Service Elementary Teachers' Conceptions of Biological Evolution and Evolution Education

    Science.gov (United States)

    Asghar, Anila; Wiles, Jason R.; Alters, Brian

    2007-01-01

    This study explores pre-service elementary school teachers' understandings of evolutionary science and their feelings and concerns about teaching evolution in Canadian elementary schools. Data were collected through a questionnaire and semi-structured interviews. Most participants reported acceptance of evolution as a scientifically factual…

  11. The Informatics (R) Evolution in Biology: The Case of Genomics

    International Nuclear Information System (INIS)

    Biology has been revolutionized by the introduction of new disciplines, such is the case of genomics that introduced in the 80s has turned unlikely to modern science, the discipline refers to the study not only of genes but their roles, relations among themselves and with the environment. Arises, with the consolidation of the human genome project and introduces us to a period of transition in which specific genetic knowledge becomes critical. Differs from other approaches in the type of information provided, the prospects for technical and intellectual improvements in the collection and use of data from the whole genome, (Murray, 2000). This work aims to investigate the recent biology, in particular, to show the history of genomics, through literature search and bibliometric analysis.

  12. The biology of human sexuality: evolution, ecology and physiology

    Directory of Open Access Journals (Sweden)

    PW Bateman

    2006-09-01

    Full Text Available Many evolutionary biologists argue that human sexual behaviour can be studied in exactly the same way as that of other species. Many sociologists argue that social influences effectively obscure, and are more important than, a reductionist biological approach to human sexual behaviour. Here,we authors attempt to provide a broad introduction to human sexual behaviour from a biological standpoint and to indicate where the ambiguous areas are. We outline the evolutionary selective pressures that are likely to have influenced human behaviour and mate choice in the past and in the present; ecological features that influence such things as degree of parental care and polygamy; and the associated physiology of human sexuality. Then they end with a discussion of �abnormal� sexuality.

  13. Synthetic Biology: Engineering, Evolution and Design (SEED) Conference 2014

    Energy Technology Data Exchange (ETDEWEB)

    Voigt, Christopher [Massachusetts Institute of Technology

    2014-07-01

    SEED2014 focused on advances in the science and technology emerging from the field of synthetic biology. We broadly define this as technologies that accelerate the process of genetic engineering. It highlighted new tool development, as well as the application of these tools to diverse problems in biotechnology, including therapeutics, industrial chemicals and fuels, natural products, and agriculture. Systems spanned from in vitro experiments and viruses, through diverse bacteria, to eukaryotes (yeast, mammalian cells, plants).

  14. Evolution of bow-tie architectures in biology

    OpenAIRE

    Friedlander, Tamar; Mayo, Avraham E.; Tlusty, Tsvi; Alon, Uri

    2014-01-01

    Bow-tie or hourglass structure is a common architectural feature found in biological and technological networks. A bow-tie in a multi-layered structure occurs when intermediate layers have much fewer components than the input and output layers. Examples include metabolism where a handful of building blocks mediate between multiple input nutrients and multiple output biomass components, and signaling networks where information from numerous receptor types passes through a small set of signalin...

  15. Evolution of bow-tie architectures in biology.

    OpenAIRE

    Tamar Friedlander; Mayo, Avraham E.; Tsvi Tlusty; Uri Alon

    2015-01-01

    Bow-tie or hourglass structure is a common architectural feature found in biological and technological networks. A bow-tie in a multi-layered structure occurs when intermediate layers have much fewer components than the input and output layers. Examples include metabolism where a handful of building blocks mediate between multiple input nutrients and multiple output biomass components, and signaling networks where information from numerous receptor types passes through a small set of signalin...

  16. Beyond Extended Phenotype Evolution of extended identity in order to reconcile study of humanity with biological evolution

    OpenAIRE

    Mezgebo, Taddese

    2014-01-01

    The question: “How much of biological evolution based theories, as they are understood presently, apply to human behaviour?” is highly controversial and perhaps highly politicized as well. The inference that human beings are evolutionarily programmed to have urges toward aggression, rape, murder, adultery, genocide and so on is a politically rejected idea within the social sciences. To be politically correct those who use evolutionary framework do claim that people can learn or have capacity ...

  17. Simple model of self-organized biological evolution as completely integrable dissipative system

    OpenAIRE

    Pis'mak, Yu. M.

    1998-01-01

    The Bak-Sneppen model of self-organized biological evolution of an infinite ecosystem of randomly interacting species is represented in terms of an infinite set of variables which can be considered as an analog to the set of integrals of motion of completely integrable system. Each of this variables remains to be constant but its influence on the evolution process is restricted in time and after definite moment its value is excluded from description of the system dynamics.

  18. Mechanical evolution of the rotating biological contactor into the 21st century.

    OpenAIRE

    Mba, David

    2003-01-01

    This paper presents a review on the evolution of the mechanical design of rotating biological contactors (RBCs) within the UK. The findings documented have been taken from the biggest mechanical survey on RBCs ever undertaken worldwide and focuses on 300 operational units. The paper looks at the main components of the RBC and discusses the evolution of each member. Mechanical deficiencies associated with each design are briefly presented, giving an insight into reasons for i...

  19. Skepsis on the scenario of Biological Evolution provided by stochastic models

    OpenAIRE

    Oikonomou, Thomas

    2008-01-01

    Stochastic models, based on random processes, may lead to power law distributions, which provide long range correlations. The observation of power law behavior and the presence of long range correlations in biological systems has been demonstrated in various studies. The combination of the two just mentioned results, theoretical and experimental, supports strongly the scenario of biological evolution across different organisms. In the current Letter we explore in a general way, using the alge...

  20. Three Southern high school biology teachers' perspectives on teaching evolution: Sociocultural influences

    Science.gov (United States)

    Kyzer, Peggy Mckewen

    Organizations in science and science education call for students to have a thorough understanding of the theory of evolution. Yet many high school biology teachers do not teach evolution and/or include creationism in their instruction (National Academy of Science, 1998). Historically, the controversy surrounding evolution has created tension for teachers. This case study explored the sociocultural influences related to teaching evolution in three Southern 10th-grade public high school biology classrooms. It also explored the socially and culturally embedded influences on teachers' instructional goals and personal perspectives toward evolution as well as modification of instruction when evolution is taught. Theoretically framed using symbolic interactionism and sociocultural theory, data were collected between October 2003 and April 2004 and included classroom observations two to three times per week, artifacts, and in-depth interviews of the participating teachers, their science department chairpersons, their students, and a Protestant minister. The classroom teachers were unaware of the focus of the study until after evolution was taught. The analysis used in this study was an inductive, interpretative approach that allowed exploration of the sociocultural influences that affect how teachers teach evolution. The sociocultural influences and the lived experiences of each teacher created a continuum for teaching evolution. One of the participating teachers who was heavily involved in the community and one of its fundamentalist churches elected to avoid teaching evolution. Another participating teacher at the same school integrated the theory of evolution in every unit. The third teacher who taught in another school elected to teach evolution in a superficial manner to avoid conflict. The data revealed that the participating teachers' sociocultural situatedness influenced their decisions and instruction on evolution. The influence of strong religious beliefs within

  1. Melanins and their possible roles through biological evolution

    Science.gov (United States)

    Césarini, J. P.

    Melanins are biopolymers which structures can be very simple or very complex. From a single essential amino acid, phenylalanine, to fully mature melanosomes, a series of events takes place: melanogenesis. A part of haemoglobin, melanins are the only pigment endogenously synthesised in humans. Their synthesis takes place in the melanocyte, a cell from neurectodermal origin (neural crest, neural tube, melanoblasts). Two important functions have been attributed to melanin: optical efficiency of the eye and colour pattern, but their role might have been much larger in lower vertebrates and several micro-organisms. By their structure, melanins have very original biophysical bioproperties. They could act as intrinsic semiconductors and may de-excite certain biological molecules by converting electronic energy into heat. Being themselves free radicals, they certainly play a major role in the quenching of free radicals produced by ultraviolet radiation. In their granular or particular form, they absorb or reflect the non-ionising radiations. Furthermore, like weak cation exchange polymers, eumelanins have the capacity to bind substantial amount of metal ions or drugs. Phaeomelanins, sulphur containing low molecular weight, may have controlled the redox state of the early steps of life on earth. In human, the skin protection role attributed to melanins is controversial. If melanins have played a major role in the establishment of a North South gradient of skin colour, it is by no mean, an adaptation phenomenon for the darker population living under strong sun exposures.

  2. gcodeml: A Grid-enabled Tool for Detecting Positive Selection in Biological Evolution

    CERN Document Server

    Moretti, Sébastien; Maffioletti, Sergio; Kuzniar, Arnold; Castella, Briséïs; Salamin, Nicolas; Robinson-Rechavi, Marc; Stockinger, Heinz

    2012-01-01

    One of the important questions in biological evolution is to know if certain changes along protein coding genes have contributed to the adaptation of species. This problem is known to be biologically complex and computationally very expensive. It, therefore, requires efficient Grid or cluster solutions to overcome the computational challenge. We have developed a Grid-enabled tool (gcodeml) that relies on the PAML (codeml) package to help analyse large phylogenetic datasets on both Grids and computational clusters. Although we report on results for gcodeml, our approach is applicable and customisable to related problems in biology or other scientific domains.

  3. Teaching of Biological Inheritance and Evolution of Living Beings in Secondary School.

    Science.gov (United States)

    Banet, E.; Ayuso, G. E.

    2003-01-01

    Examines solutions to problems involved in the learning and teaching of biological inheritance and the evolution of living beings at the secondary school level. Shows that the program instilled knowledge close to what is adequate for this educational level. Proposes disciplinary criteria for selecting and sequencing the content to be taught and…

  4. Use of the "Tree" Analogy in Evolution Teaching by Biology Teachers

    Science.gov (United States)

    Marcelos, Maria Fatima; Nagem, Ronaldo Luiz

    2012-01-01

    This work discusses the use of Darwin's "Tree of Life" as a didactic analogy and metaphor in teaching evolution. It investigates whether biology teachers of pupils from 17 to 18 years old know Darwin's text "Tree of Life". In addition, it examines whether those teachers systematically employ either the analogies present in that text or other…

  5. The search for life's origins: Progress and future directions in planetary biology and chemical evolution

    Science.gov (United States)

    1990-01-01

    The current state is reviewed of the study of chemical evolution and planetary biology and the probable future is discussed of the field, at least for the near term. To this end, the report lists the goals and objectives of future research and makes detailed, comprehensive recommendations for accomplishing them, emphasizing those issues that were inadequately discussed in earlier Space Studies Board reports.

  6. Solution of the Master Equation for Bak-Sneppen Model of Biological Evolution in Finite Ecosystem

    OpenAIRE

    Pis'mak, Yu. M.

    1996-01-01

    The master equations describing processes of biological evolution in the framework of the random neighbor Bak-Sneppen model are studied. For the eqosystem of $N$ species they are solved exactly and asymptotical behavior of this solution for large $N$ is analyzed.

  7. Asymptotic Fitness Distribution in the Bak-Sneppen Model of Biological Evolution with Four Species

    Science.gov (United States)

    Schlemm, Eckhard

    2012-08-01

    We suggest a new method to compute the asymptotic fitness distribution in the Bak-Sneppen model of biological evolution. As applications we derive the full asymptotic distribution in the four-species model, and give an explicit linear recurrence relation for a set of coefficients determining the asymptotic distribution in the five-species model.

  8. Asymptotic fitness distribution in the Bak-Sneppen model of biological evolution with four species

    OpenAIRE

    Schlemm, Eckhard

    2012-01-01

    We suggest a new method to compute the asymptotic fitness distribution in the Bak-Sneppen model of biological evolution. As applications we derive the full asymptotic distribution in the four-species model, and give an explicit linear recurrence relation for a set of coefficients determining the asymptotic distribution in the five-species model.

  9. The genome sequence of taurine cattle: A window to ruminant biology and evolution

    Science.gov (United States)

    To understand the biology and evolution of ruminants, the cattle genome was sequenced to about sevenfold coverage. The cattle genome contains a minimum of 22,000 genes, with a core set of 14,345 orthologs shared among seven mammalian species of which 1217 are absent or undetected in noneutherian (ma...

  10. The Genome Sequence of Taurine Cattle: A Window to Ruminant Biology and Evolution

    Science.gov (United States)

    As a major step toward understanding the biology and evolution of ruminants, the cattle genome was sequenced to ~7x coverage using a combined whole genome shotgun and BAC skim approach. The cattle genome contains a minimum of 22,000 genes, with a core set of 14,345 orthologs found in seven mammalian...

  11. Without the Light of Evolution: A Case Study of Resistance and Avoidance in Learning to Teach High School Biology

    Science.gov (United States)

    Larkin, Douglas B.; Perry-Ryder, Gail M.

    2015-01-01

    We present the case of Michael, a prospective high school biology teacher, to explore the implications of teacher resistance and avoidance to the topic of evolution. This case is drawn from a year-long qualitative research study that examined Michael's process of learning to teach high school biology and describes how his avoidance of evolution in…

  12. Punctuated equilibrium and shock waves in molecular models of biological evolution

    Science.gov (United States)

    Saakian, David B.; Ghazaryan, Makar H.; Hu, Chin-Kun

    2014-08-01

    We consider the dynamics in infinite population evolution models with a general symmetric fitness landscape. We find shock waves, i.e., discontinuous transitions in the mean fitness, in evolution dynamics even with smooth fitness landscapes, which means that the search for the optimal evolution trajectory is more complicated. These shock waves appear in the case of positive epistasis and can be used to represent punctuated equilibria in biological evolution during long geological time scales. We find exact analytical solutions for discontinuous dynamics at the large-genome-length limit and derive optimal mutation rates for a fixed fitness landscape to send the population from the initial configuration to some final configuration in the fastest way.

  13. Markov Chain-Like Quantum Biological Modeling of Mutations, Aging, and Evolution

    Directory of Open Access Journals (Sweden)

    Ivan B. Djordjevic

    2015-08-01

    Full Text Available Recent evidence suggests that quantum mechanics is relevant in photosynthesis, magnetoreception, enzymatic catalytic reactions, olfactory reception, photoreception, genetics, electron-transfer in proteins, and evolution; to mention few. In our recent paper published in Life, we have derived the operator-sum representation of a biological channel based on codon basekets, and determined the quantum channel model suitable for study of the quantum biological channel capacity. However, this model is essentially memoryless and it is not able to properly model the propagation of mutation errors in time, the process of aging, and evolution of genetic information through generations. To solve for these problems, we propose novel quantum mechanical models to accurately describe the process of creation spontaneous, induced, and adaptive mutations and their propagation in time. Different biological channel models with memory, proposed in this paper, include: (i Markovian classical model, (ii Markovian-like quantum model, and (iii hybrid quantum-classical model. We then apply these models in a study of aging and evolution of quantum biological channel capacity through generations. We also discuss key differences of these models with respect to a multilevel symmetric channel-based Markovian model and a Kimura model-based Markovian process. These models are quite general and applicable to many open problems in biology, not only biological channel capacity, which is the main focus of the paper. We will show that the famous quantum Master equation approach, commonly used to describe different biological processes, is just the first-order approximation of the proposed quantum Markov chain-like model, when the observation interval tends to zero. One of the important implications of this model is that the aging phenotype becomes determined by different underlying transition probabilities in both programmed and random (damage Markov chain-like models of aging, which

  14. [Historic and functional biology: the inadequacy of a system theory of evolution].

    Science.gov (United States)

    Regelmann, J P

    1982-01-01

    In the first half of the 20th century neo-Kantianism in a broad sense proved itself the main conceptual and methodological background of the central European biology. As such it contributed much to the victory on the typological, idealistic-morphological and psycho-vitalistic interpretations of life. On the other hand it could not give tools to the biologists for working out a strictly darwinian evolution theory. Kant's theory of organism was conceived without evolution as a theory of the internal functionality of the organism. There was only some 'play' with the evolutionary differentiation of the species. Since then the disputes around the work of August Weismann, a synthetical evolution theory which is now behind time, arose. This theory developed from coinciding claims, elaborated by geneticists, mathematicians, and by biologists studying development, natural history and systematics. This was done under a strong influence of marxist ideas. Through the interweaving of such different approaches it was possible for this evolutionary synthesis to influence successfully the development of evolution research during more than 40 years. Philosophically speaking modern evolution theory means therefore an aversion, even a positive abolition of Kantian positions. A number of biologists however--as L. von Bertalanffy--refused to adhere to a misinterpreted Kantian methodology and oriented themselves to an approach via system theory, which obtained a place in evolution research. In fact this is a Kantian approach as well. They only repeated the Kantian dilemma of the evolution which can also be found in Lamarck and Hegel. The system theory of the functionality of the organism never reaches to the level of the evolving species, but remains always on the level of epigenetic thinking, because of its philosophical origin. This paper points out the consequences of this still current dilemma. At the same time an all-enclosing reflection on the methodological, epistemological and

  15. Human evolution, life history theory, and the end of biological reproduction.

    Science.gov (United States)

    Last, Cadell

    2014-01-01

    Throughout primate history there have been three major life history transitions towards increasingly delayed sexual maturation and biological reproduction, as well as towards extended life expectancy. Monkeys reproduce later and live longer than do prosimians, apes reproduce later and live longer than do monkeys, and humans reproduce later and live longer than do apes. These life history transitions are connected to increased encephalization. During the last life history transition from apes to humans, increased encephalization co-evolved with increased dependence on cultural knowledge for energy acquisition. This led to a dramatic pressure for more energy investment in growth over current biological reproduction. Since the industrial revolution socioeconomic development has led to even more energy being devoted to growth over current biological reproduction. I propose that this is the beginning of an ongoing fourth major primate life history transition towards completely delayed biological reproduction and an extension of the evolved human life expectancy. I argue that the only fundamental difference between this primate life history transition and previous life history transitions is that this transition is being driven solely by cultural evolution, which may suggest some deeper evolutionary transition away from biological evolution is already in the process of occurring. PMID:24852016

  16. The Genome Sequence of Taurine Cattle: A Window to Ruminant Biology and Evolution

    OpenAIRE

    Elsik, Christine G; Tellam, Ross L.; Worley, Kim C.; Gibbs, Richard A; Abatepaulo, Antonio R. R.; Abbey, Colette A.; Adelson, David L.; Aerts, Jan; Ahola, Virpi; Alexander, Lee; Alioto, Tyler; Almeida, Iassudara G.; Amadio, Ariel F.; Anatriello, Elen; Antonarakis, Stylianos E

    2009-01-01

    To understand the biology and evolution of ruminants, the cattle genome was sequenced to about sevenfold coverage. The cattle genome contains a minimum of 22,000 genes, with a core set of 14,345 orthologs shared among seven mammalian species of which 1217 are absent or undetected in noneutherian (marsupial or monotreme) genomes. Cattle-specific evolutionary breakpoint regions in chromosomes have a higher density of segmental duplications, enrichment of repetitive elements, and species-specifi...

  17. A hypothesis on the biological origins and social evolution of music and dance

    OpenAIRE

    Wang, Tianyan

    2015-01-01

    The origins of music and musical emotions is still an enigma, here I propose a comprehensive hypothesis on the origins and evolution of music, dance, and speech from a biological and sociological perspective. I suggest that every pitch interval between neighboring notes in music represents corresponding movement pattern through interpreting the Doppler effect of sound, which not only provides a possible explanation for the transposition invariance of music, but also integrates music and dance...

  18. Pheromone-inducible conjugation in Enterococcus faecalis: A model for the evolution of biological complexity?

    OpenAIRE

    Kozlowicz, Briana K.; Dworkin, Martin; Dunny, Gary M.

    2006-01-01

    Pheromone-inducible transfer of the plasmid pCF10 in Enterococcus faecalis is regulated using a complicated network of proteins and RNAs. The plasmid itself has been assembled from parts garnered from a variety of sources, and many aspects of the system resemble a biological kluge. Recently several new functions of various pCF10 gene products that participate in regulation of plasmid transfer have been identified. The results indicate that selective pressures controlling the evolution of the ...

  19. Chemical and biological evolution of (U-14C)phenol sorbed on activated carbon

    International Nuclear Information System (INIS)

    Methods describing the chemical and biological evolution of (U-14C)phenol adsorbed on activated carbon are given with or without the use of bacteria. Without bacteria, the (U-14C)phenol initially adsorbed is not removed from the carbon after adding a solution of unlabelled phenol through the column for eight days. With bacteria, the (U-14C)phenol initially present, is removed (60-70%) from activated carbon with a solution containing unlabelled phenol, nitrogen and phosphorus. (author)

  20. Mutagens and carcinogens - Occurrence and role during chemical and biological evolution

    Science.gov (United States)

    Giner-Sorolla, A.; Oro, J.

    1981-01-01

    The roles of mutagenic and carcinogenic substances in early biologic evolution is examined, along with terrestrial and extraterrestrial sources of mutagens and carcinogens. UV solar radiation is noted to have served to stimulate prebiotic life while also causing harmful effects in plants and animals. Aromatic compounds have been found in meteorites, and comprise leukemogens, polycyclic hydrocarbons, and nitrasamine precursors. Other mutagenic sources are volcanoes, and the beginning of evolution with mutagenic substances is complicated by the appearance of malignancies due to the presence of carcinogens. The atmosphere of the Precambrian period contained both mutagens and early carcinogens and, combined with volcanic activity discharges, formed an atmospheric chemical background analogous to the background ionizing radiation. Carcinogenesis is concluded to be intrinsic to nature, having initiated evolution and, eventually, cancer cells.

  1. MBEToolbox: a Matlab toolbox for sequence data analysis in molecular biology and evolution

    Directory of Open Access Journals (Sweden)

    Xia Xuhua

    2005-03-01

    Full Text Available Abstract Background MATLAB is a high-performance language for technical computing, integrating computation, visualization, and programming in an easy-to-use environment. It has been widely used in many areas, such as mathematics and computation, algorithm development, data acquisition, modeling, simulation, and scientific and engineering graphics. However, few functions are freely available in MATLAB to perform the sequence data analyses specifically required for molecular biology and evolution. Results We have developed a MATLAB toolbox, called MBEToolbox, aimed at filling this gap by offering efficient implementations of the most needed functions in molecular biology and evolution. It can be used to manipulate aligned sequences, calculate evolutionary distances, estimate synonymous and nonsynonymous substitution rates, and infer phylogenetic trees. Moreover, it provides an extensible, functional framework for users with more specialized requirements to explore and analyze aligned nucleotide or protein sequences from an evolutionary perspective. The full functions in the toolbox are accessible through the command-line for seasoned MATLAB users. A graphical user interface, that may be especially useful for non-specialist end users, is also provided. Conclusion MBEToolbox is a useful tool that can aid in the exploration, interpretation and visualization of data in molecular biology and evolution. The software is publicly available at http://web.hku.hk/~jamescai/mbetoolbox/ and http://bioinformatics.org/project/?group_id=454.

  2. Exploring the Factors Related to Acceptance of Evolutionary Theory among Turkish Preservice Biology Teachers: Toward a More Informative Conceptual Ecology for Biological Evolution

    Science.gov (United States)

    Deniz, Hasan; Donnelly, Lisa A.; Yilmaz, Irfan

    2008-01-01

    In this study, using multiple regression analysis, we aimed to explore the factors related to acceptance of evolutionary theory among preservice Turkish biology teachers using conceptual ecology for biological evolution as a theoretical lens. We aimed to determine the extent to which we can account for the variance in acceptance of evolutionary…

  3. The evolution of early cellular systems viewed through the lens of biological interactions

    Directory of Open Access Journals (Sweden)

    Anthony M Poole

    2015-10-01

    Full Text Available The minimal cell concept represents a pragmatic approach to the question of how few genes are required to run a cell. This is a helpful way to build a parts-list, and has been more successful than attempts to deduce a minimal gene set for life by inferring the gene repertoire of the Last Universal Common Ancestor, as few genes trace back to this hypothetical ancestral state. However, the study of minimal cellular systems is the study of biological outliers where, by practical necessity, coevolutionary interactions are minimised or ignored. In this paper, we consider the biological context from which minimal genomes have been removed. For instance, some of the most reduced genomes are from endosymbionts and are the result of coevolutionary interactions with a host; few such organisms are ‘free-living’. As few, if any, biological systems exist in complete isolation, we expect that, as with modern life, early biological systems were part of an ecosystem, replete with organismal interactions. We favour refocusing discussions of the evolution of cellular systems on processes rather than gene counts. We therefore draw a distinction between a pragmatic minimal cell (an interesting engineering problem, a distributed genome (a system resulting from an evolutionary transition involving more than one cell and the looser coevolutionary interactions that are ubiquitous in ecosystems. Finally, we consider the distributed genome and coevolutionary interactions between genomic entities in the context of early evolution.

  4. Biological stoichiometry: a theoretical framework connecting ecosystem ecology, evolution, and biochemistry for application in astrobiology

    Science.gov (United States)

    Elser, James J.

    2003-07-01

    Astrobiology is an extremely wide-ranging field and thus is in special need of conceptual and theoretical frameworks that can integrate its various arenas of study. In this paper I review recent work associated with a conceptual framework known as "ecological stoichiometry" and even more recent extensions in the development of "biological stoichiometry". Ecological stoichiometry is the study of the balance of energy and multiple chemical elements in ecological interactions and has developed rapidly in the study of nutrient cycling and energy flow in aquatic food webs. It identifies the elemental composition of interacting biota as central in understanding the nature of their interactions and dynamics, including key feedbacks via nutrient recycling. Biological stoichiometry extends this mode of thinking to all types of biological systems. It especially seeks to better understand, at the biochemical and genetic levels, the factors influencing the elemental composition of living things and the evolutionary forces that drive and constrain that elemental composition. By connecting key concepts of ecosystem ecology, evolutionary biology and biochemistry, stoichiometric theory integrates biological information into a more coherent whole that holds considerable promise for application in astrobiology. Several examples of potential astrobiological applications of stoichiometric analysis are offered, including ones related to pre-biotic evolution, the Cambrian explosion, biosignatures and biological feedbacks on planetary carbon cycling.

  5. Evolution of Marine Organisms under Climate Change at Different Levels of Biological Organisation

    Directory of Open Access Journals (Sweden)

    Ben P. Harvey

    2014-11-01

    Full Text Available Research to date has suggested that both individual marine species and ecological processes are expected to exhibit diverse responses to the environmental effects of climate change. Evolutionary responses can occur on rapid (ecological timescales, and yet studies typically do not consider the role that adaptive evolution will play in modulating biological responses to climate change. Investigations into such responses have typically been focused at particular biological levels (e.g., cellular, population, community, often lacking interactions among levels. Since all levels of biological organisation are sensitive to global climate change, there is a need to elucidate how different processes and hierarchical interactions will influence species fitness. Therefore, predicting the responses of communities and populations to global change will require multidisciplinary efforts across multiple levels of hierarchy, from the genetic and cellular to communities and ecosystems. Eventually, this may allow us to establish the role that acclimatisation and adaptation will play in determining marine community structures in future scenarios.

  6. Mechanical biological treatment of organic fraction of MSW affected dissolved organic matter evolution in simulated landfill.

    Science.gov (United States)

    Salati, Silvia; Scaglia, Barbara; di Gregorio, Alessandra; Carrera, Alberto; Adani, Fabrizio

    2013-08-01

    The aim of this paper was to study the evolution of DOM during 1 year of observation in simulated landfill, of aerobically treated vs. untreated organic fraction of MSW. Results obtained indicated that aerobic treatment of organic fraction of MSW permitted getting good biological stability so that, successive incubation under anaerobic condition in landfill allowed biological process to continue getting a strong reduction of soluble organic matter (DOM) that showed, also, an aromatic character. Incubation of untreated waste gave similar trend, but in this case DOM decreasing was only apparent as inhibition of biological process in landfill did not allow replacing degraded/leached DOM with new material coming from hydrolysis of fresh OM. PMID:23743423

  7. Student world view as a framework for learning genetics and evolution in high school biology

    Science.gov (United States)

    McCoy, Roger Wesley

    Statement of the problem. Few studies in biology education have examined the underlying presuppositions which guide thinking and concept learning in adolescents. The purpose of this study was to describe and understand the biological world views of a variety of high school students before they take biology courses. Specifically, the study examined student world views in the domains of Classification, Relationship and Causation related to the concepts of heredity, evolution and biotechnology. The following served as guiding questions: (1) What are the personal world views of high school students entering biology classes, related to the domain of Classification, Relationship and Causality? (2) How do these student world views confound or enhance the learning of basic concepts in genetics and evolution? Methods. An interpretive method was chosen for this study. The six student participants were ninth graders and represented a wide range of world view backgrounds. A series of three interviews was conducted with each participant, with a focus group used for triangulation of data. The constant comparative method was used to categorize the data and facilitate the search for meaningful patterns. The analysis included a thick description of each student's personal views of classification, evolution and the appropriate use of biotechnology. Results. The study demonstrates that world view is the basis upon which students build knowledge in biology. The logic of their everyday thinking may not match that of scientists. The words they use are sometimes inconsistent with scientific terminology. This study provides evidence that students voice different opinions depending on the social situation, since they are strongly influenced by peers. Students classify animals based on behaviors. They largely believe that the natural world is unpredictable, and that humans are not really part of that world. Half are unlikely to accept the evolution of humans, but may accept it in other

  8. Does the nature of science influence college students' learning of biological evolution?

    Science.gov (United States)

    Butler, Wilbert, Jr.

    This quasi-experimental, mixed-methods study assessed the influence of the nature of science (NOS) instruction on college students' learning of biological evolution. In this research, conducted in two introductory biology courses, in each course the same instruction was employed, with one important exception: in the experimental section students were involved in an explicit, reflective treatment of the nature of science (Explicit, reflective NOS), in the traditional treatment section, NOS was implicitly addressed (traditional treatment). In both sections, NOS aspects of science addressed included is tentative, empirically based, subjective, inferential, and based on relationship between scientific theories and laws. Students understanding of evolution, acceptance of evolution, and understanding of the nature of science were assessed before, during and after instruction. Data collection entailed qualitative and quantitative methods including Concept Inventory for Natural Selection (CINS), Measure of Acceptance of the Theory of Evolution (MATE) survey, Views of nature of Science (VNOS-B survey), as well as interviews, classroom observations, and journal writing to address understand students' views of science and understanding and acceptance of evolution. The quantitative data were analyzed via inferential statistics and the qualitative data were analyzed using grounded theory. The data analysis allowed for the construction and support for four assertions: Assertion 1: Students engaged in explicit and reflective NOS specific instruction significantly improved their understanding of the nature of science concepts. Alternatively, students engaged in instruction using an implicit approach to the nature of science did not improve their understanding of the nature of science to the same degree. The VNOS-B results indicated that students in the explicit, reflective NOS class showed the better understanding of the NOS after the course than students in the implicit NOS class

  9. Mapping biological ideas: Concept maps as knowledge integration tools for evolution education

    Science.gov (United States)

    Schwendimann, Beat Adrian

    Many students leave school with a fragmented understanding of biology that does not allow them to connect their ideas to their everyday lives (Wandersee, 1989; Mintzes, Wandersee, & Novak, 1998; Mintzes, Wandersee, & Novak, 2000a). Understanding evolution ideas is seen as central to building an integrated knowledge of biology (Blackwell, Powell, & Dukes, 2003; Thagard & Findlay, 2010). However, the theory of evolution has been found difficult to understand as it incorporates a wide range of ideas from different areas (Bahar et al., 1999; Tsui & Treagust, 2003) and multiple interacting levels (Wilensky & Resnick, 1999; Duncan & Reiser, 2007; Hmelo-Silver et al., 2007). Research suggests that learners can hold a rich repertoire of co-existing alternative ideas of evolution (for example, Bishop & Anderson, 1990; Demastes, Good, & Peebles, 1996; Evans, 2008), especially of human evolution (for example, Nelson, 1986; Sinatra et al., 2003; Poling & Evans, 2004). Evolution ideas are difficult to understand because they often contradict existing alternative ideas (Mayr, 1982; Wolpert, 1994; Evans, 2008). Research suggests that understanding human evolution is a key to evolution education (for example, Blackwell et al., 2003; Besterman & Baggott la Velle, 2007). This dissertation research investigates how different concept mapping forms embedded in a collaborative technology-enhanced learning environment can support students' integration of evolution ideas using case studies of human evolution. Knowledge Integration (KI) (Linn et al., 2000; Linn et al., 2004) is used as the operational framework to explore concept maps as knowledge integration tools to elicit, add, critically distinguish, group, connect, and sort out alternative evolution ideas. Concept maps are a form of node-link diagram for organizing and representing connections between ideas as a semantic network (Novak & Gowin, 1984). This dissertation research describes the iterative development of a novel biology

  10. Insects as test systems for assessing the potential role of microgravity in biological development and evolution

    Science.gov (United States)

    Vernós, I.; Carratalá, M.; González-Jurado, J.; Valverde, J. R.; Calleja, M.; Domingo, A.; Vinós, J.; Cervera, M.; Marco, R.

    Gravity and radiation are undoubtedly the two major environmental factors altered in space. Gravity is a weak force, which creates a permanent potential field acting on the mass of biological systems and their cellular components, strongly reduced in space flights. Developmental systems, particularly at very early stages, provide the larger cellular compartments known, where the effects of alterations in the size of the gravity vector on living organisms can be more effectively tested. The insects, one of the more highly evolved classes of animals in which early development occurs in a syncytial embryo, are systems particularly well suited to test these effects and the specific developmental mechanisms affected. Furthermore, they share some basic features such as small size, short life cycles, relatively high radio-resistance, etc. and show a diversity of developmental strategies and tempos advantageous in experiments of this type in space. Drosophila melanogaster, the current biological paradigm to study development, with so much genetic and evolutionary background available, is clearly the reference organism for these studies. The current evidence on the effects of the physical parameters altered in space flights on insect development indicate a surprising correlation between effects seen on the fast developing and relatively small Drosophila embryo and the more slowly developing and large Carausius morosus system. In relation to the issue of the importance of developmental and environmental constraints in biological evolution, still the missing link in current evolutionary thinking, insects and space facilities for long-term experiments could provide useful experimental settings where to critically assess how development and evolution may be interconnected. Finally, it has to be pointed out that since there are experimental data indicating a possible synergism between microgravity and space radiation, possible effects of space radiation should be taken into

  11. Mobility as an emergent property of biological organization: Insights from experimental evolution.

    Science.gov (United States)

    Wallace, Ian J; Garland, Theodore

    2016-05-01

    Anthropologists accept that mobility is a critical dimension of human culture, one that links economy, technology, and social relations. Less often acknowledged is that mobility depends on complex and dynamic interactions between multiple levels of our biological organization, including anatomy, physiology, neurobiology, and genetics. Here, we describe a novel experimental approach to examining the biological foundations of mobility, using mice from a long-term artificial selection experiment for high levels of voluntary exercise on wheels. In this experiment, mice from selectively bred lines have evolved to run roughly three times as far per day as those from nonselected control lines. We consider three insights gleaned from this experiment as foundational principles for the study of mobility from the perspective of biological evolution. First, an evolutionary change in mobility will necessarily be associated with alterations in biological traits both directly and indirectly connected to mobility. Second, changing mobility will result in trade-offs and constraints among some of the affected traits. Third, multiple solutions exist to altering mobility, so that various combinations of adjustments to traits linked with mobility can achieve the same overall behavioral outcome. We suggest that anthropological knowledge of variation in human mobility might be improved by greater research attention to its biological dimensions. PMID:27312181

  12. Controversy in Biology Classrooms-Citizen Science Approaches to Evolution and Applications to Climate Change Discussions.

    Science.gov (United States)

    Yoho, Rachel A; Vanmali, Binaben H

    2016-03-01

    The biological sciences encompass topics considered controversial by the American public, such as evolution and climate change. We believe that the development of climate change education in the biology classroom is better informed by an understanding of the history of the teaching of evolution. A common goal for science educators should be to engender a greater respect for and appreciation of science among students while teaching specific content knowledge. Citizen science has emerged as a viable yet underdeveloped method for engaging students of all ages in key scientific issues that impact society through authentic data-driven scientific research. Where successful, citizen science may open avenues of communication and engagement with the scientific process that would otherwise be more difficult to achieve. Citizen science projects demonstrate versatility in education and the ability to test hypotheses by collecting large amounts of often publishable data. We find a great possibility for science education research in the incorporation of citizen science projects in curriculum, especially with respect to "hot topics" of socioscientific debate based on our review of the findings of other authors. Journal of Microbiology & Biology Education. PMID:27047604

  13. The Sensitivity of Earth's Climate History To Changes In The Rates of Biological And Geological Evolution

    Science.gov (United States)

    Waltham, D.

    2014-12-01

    The faint young Sun paradox (early Earth had surface liquid water despite solar luminosity 70% of the modern value) implies that our planet's albedo has increased through time and/or greenhouse warming has fallen. The obvious explanation is that negative feedback processes stabilized temperatures. However, the limited temperature data available does not exhibit the expected residual temperature rise and, at least for the Phanerozoic, estimates of climate sensitivity exceed the Planck sensitivity (the zero net-feedback value). The alternate explanation is that biological and geological evolution have tended to cool Earth through time hence countering solar-driven warming. The coincidence that Earth-evolution has roughly cancelled Solar-evolution can then be explained as an emergent property of a complex system (the Gaia hypothesis) or the result of the unavoidable observational bias that Earth's climate history must be compatible with our existence (the anthropic principle). Here, I use a simple climate model to investigate the sensitivity of Earth's climate to changes in the rate of Earth-evolution. Earth-evolution is represented by an effective emissivity which has an intrinsic variation through time (due to continental growth, the evolution of cyanobacteria, orbital fluctuations etc) plus a linear feedback term which enhances emissivity variations. An important feature of this model is a predicted maximum in the radiated-flux versus temperature function. If the increasing solar flux through time had exceeded this value then runaway warming would have occurred. For the best-guess temperature history and climate sensitivity, the Earth has always been within a few percent of this maximum. There is no obvious Gaian explanation for this flux-coincidence but the anthropic principle naturally explains it: If the rate of biological/geological evolution is naturally slow then Earth is a fortunate outlier which evolved just fast enough to avoid solar-induced over

  14. Transforming Misconceptions: Using Transformative Experience to Promote Positive Affect and Conceptual Change in Students Learning about Biological Evolution

    Science.gov (United States)

    Heddy, Benjamin C.; Sinatra, Gale M.

    2013-01-01

    Teaching and learning about complex scientific content, such as biological evolution, is challenging in part because students have a difficult time seeing the relevance of evolution in their everyday lives. The purpose of this study was to explore the effectiveness of the Teaching for Transformative Experiences in Science (TTES) model (Pugh, 2002)…

  15. Self-Organized Criticality in the Model of Biological Evolution Describing Interaction of "Coenophilous" and " Coenophobous" Species

    OpenAIRE

    O. V. Kovalev; Pis'mak, Yu. M.; Vechernin, V. V.

    1995-01-01

    The modification of the model of P.Bak and K.Sneppen of the self-organized biological evolution is proposed on the basis of a formalization of the scheme of the biosphere evolution suggested by O.V.Kovalev. This scheme is regarded as one approximating the realistic model of the ecosystem evolution. The fundamental difference between "coenophilous" species and "coenophobous" ones in respect to their reaction on the external environment is represented. The dynamics of the modified model as well...

  16. THE EVOLUTION OF THE KREBS CYCLE: A PROMISING THEME FOR MEANINGFUL BIOCHEMISTRY LEARNING IN BIOLOGY

    Directory of Open Access Journals (Sweden)

    C. Costa

    2015-08-01

    Full Text Available INTRODUCTION: Evolution has been recognized as a key concept for biologists. In order to motivate biology undergraduates for contents of central energetic metabolism, we addressed the Krebs cycle structure and functions to an evolutionary view. To this end, we created a study guide which contextualizes the emergence of the cyclic pathway, in light of the prokaryotic influence since early Earth anaerobic condition to oxygen rise in atmosphere. OBJECTIVES: The main goal is to highlight the educational potential of the material whose subject is scarcely covered in biochemistry textbooks. MATERIALS AND METHODS: The study guide is composed by three interrelated sections, the problem (Section 1, designed to arouse curiosity, inform and motivate students; an introductory text (Section 2 about life evolution, including early micro-organisms and Krebs cycle emergence, and questions (Section 3 for debate. The activity consisted on a peer discussion session, with instructors tutoring. The questions were designed to foster exchange of ideas in an ever-increasing level of complexity, and cover subjects from early atmospheric conditions to organization of the metabolism along the subsequent geological ages. RESULTS AND DISCUSSION: We noticed that students were engaged and motivated by the task, especially during group discussion. Based on students’ feedbacks and class observations, we learned that the material raised curiosity and stimulated discussion among peers. It brought a historical and purposeful way of dealing with difficult biochemical concepts. CONCLUSIONS: The whole experience suggests that the study guide was a stimulus for broadening comprehension of the Krebs cycle, reinforcing the evolutionary stance as an important theme for biology and biochemistry understanding. On the other hand, we do not underestimate the fact that approaching Krebs cycle from an evolutionary standpoint is a quite complex discussion for the majority of students

  17. From the ultrasonic to the infrared: molecular evolution and the sensory biology of bats.

    Science.gov (United States)

    Jones, Gareth; Teeling, Emma C; Rossiter, Stephen J

    2013-01-01

    Great advances have been made recently in understanding the genetic basis of the sensory biology of bats. Research has focused on the molecular evolution of candidate sensory genes, genes with known functions [e.g., olfactory receptor (OR) genes] and genes identified from mutations associated with sensory deficits (e.g., blindness and deafness). For example, the FoxP2 gene, underpinning vocal behavior and sensorimotor coordination, has undergone diversification in bats, while several genes associated with audition show parallel amino acid substitutions in unrelated lineages of echolocating bats and, in some cases, in echolocating dolphins, representing a classic case of convergent molecular evolution. Vision genes encoding the photopigments rhodopsin and the long-wave sensitive opsin are functional in bats, while that encoding the short-wave sensitive opsin has lost functionality in rhinolophoid bats using high-duty cycle laryngeal echolocation, suggesting a sensory trade-off between investment in vision and echolocation. In terms of olfaction, bats appear to have a distinctive OR repertoire compared with other mammals, and a gene involved in signal transduction in the vomeronasal system has become non-functional in most bat species. Bitter taste receptors appear to have undergone a "birth-and death" evolution involving extensive gene duplication and loss, unlike genes coding for sweet and umami tastes that show conservation across most lineages but loss in vampire bats. Common vampire bats have also undergone adaptations for thermoperception, via alternative splicing resulting in the evolution of a novel heat-sensitive channel. The future for understanding the molecular basis of sensory biology is promising, with great potential for comparative genomic analyses, studies on gene regulation and expression, exploration of the role of alternative splicing in the generation of proteomic diversity, and linking genetic mechanisms to behavioral consequences. PMID:23755015

  18. From the ultrasonic to the infrared: molecular evolution and the sensory biology of bats

    Directory of Open Access Journals (Sweden)

    Gareth eJones

    2013-05-01

    Full Text Available Great advances have been made recently in understanding the genetic basis of the sensory biology of bats. Research has focused on the molecular evolution of candidate sensory genes, genes with known functions (e.g. olfactory receptor genes and genes identified from mutations associated with sensory deficits (e.g. blindness and deafness. For example, the FoxP2 gene, underpinning vocal behaviour and sensorimotor coordination, has undergone diversification in bats, while several genes associated with audition show parallel amino acid substitutions in unrelated lineages of echolocating bats and, in some cases, in echolocating dolphins, representing a classic case of convergent molecular evolution. Vision genes encoding the photopigments rhodopsin and the long-wave sensitive opsin are functional in bats, while that encoding the short-wave sensitive opsin has lost functionality in rhinolophoid bats using high-duty cycle laryngeal echolocation, suggesting a sensory trade-off between investment in vision and echolocation. In terms of olfaction, bats appear to have a distinctive olfactory receptor repertoire compared with other mammals, and a gene involved in signal transduction in the vomeronasal system has become non-functional in most bat species. Bitter taste receptors appear to have undergone a ‘birth-and death’ evolution involving extensive gene duplication and loss, unlike genes coding for sweet and umami tastes that show conservation across most lineages but loss in vampire bats. Common vampire bats have also undergone adaptations for thermoperception, via alternative splicing resulting in the evolution of a novel heat-sensitive channel. The future for understanding the molecular basis of sensory biology is promising, with great potential for comparative genomic analyses, studies on gene regulation and expression, exploration of the role of alternative splicing in the generation of proteomic diversity, and linking genetic mechanisms to

  19. Symbiosis in the Bak Sneppen model for biological evolution with economic applications

    Science.gov (United States)

    Bartolozzi, M.; Leinweber, D. B.; Thomas, A. W.

    2006-06-01

    In the present work we extend the Bak-Sneppen model for biological evolution by introducing local interactions between species. This “environmental” perturbation modifies the intrinsic fitness of each element of the ecology, leading to higher survival probability, even for the less fit. While the system still self-organizes toward a critical state, the distribution of fitness broadens, losing the classical step-function shape. A possible application in economics is discussed, where firms are represented as evolving species linked by mutual interests.

  20. Controversy in Biology Classrooms—Citizen Science Approaches to Evolution and Applications to Climate Change Discussions

    Directory of Open Access Journals (Sweden)

    Rachel A. Yoho

    2015-11-01

    Full Text Available The biological sciences encompass topics considered controversial by the American public, such as evolution and climate change. We believe that the development of climate change education in the biology classroom is better informed by an understanding of the history of the teaching of evolution. A common goal for science educators should be to engender a greater respect for and appreciation of science among students while teaching specific content knowledge. Citizen science has emerged as a viable yet underdeveloped method for engaging students of all ages in key scientific issues that impact society through authentic data-driven scientific research. Where successful, citizen science may open avenues of communication and engagement with the scientific process that would otherwise be more difficult to achieve. Citizen science projects demonstrate versatility in education and the ability to test hypotheses by collecting large amounts of often publishable data. We find a great possibility for science education research in the incorporation of citizen science projects in curriculum, especially with respect to “hot topics” of socioscientific debate based on our review of the findings of other authors.

  1. Life’s a Gas: A Thermodynamic Theory of Biological Evolution

    Directory of Open Access Journals (Sweden)

    Keith R. Skene

    2015-07-01

    Full Text Available This paper outlines a thermodynamic theory of biological evolution. Beginning with a brief summary of the parallel histories of the modern evolutionary synthesis and thermodynamics, we use four physical laws and processes (the first and second laws of thermodynamics, diffusion and the maximum entropy production principle to frame the theory. Given that open systems such as ecosystems will move towards maximizing dispersal of energy, we expect biological diversity to increase towards a level, Dmax, representing maximum entropic production (Smax. Based on this theory, we develop a mathematical model to predict diversity over the last 500 million years. This model combines diversification, post-extinction recovery and likelihood of discovery of the fossil record. We compare the output of this model with that of the observed fossil record. The model predicts that life diffuses into available energetic space (ecospace towards a dynamic equilibrium, driven by increasing entropy within the genetic material. This dynamic equilibrium is punctured by extinction events, which are followed by restoration of Dmax through diffusion into available ecospace. Finally we compare and contrast our thermodynamic theory with the MES in relation to a number of important characteristics of evolution (progress, evolutionary tempo, form versus function, biosphere architecture, competition and fitness.

  2. The biological evolution of conscience – from parent-offspring conflict to morality

    Directory of Open Access Journals (Sweden)

    Voland Eckart

    2014-12-01

    Full Text Available In this paper, two theories regarding the biological evolution of morality with conscience as its central regulatory agency are compared and contrasted. One theory (“navigator theory” interprets conscience as a strategically operating agency for the optimum balance between selfish and altruistic behavioral tendencies to maximize gains in cooperation in view of social complexity. From this standpoint, conscience serves the evolved self-interest of the person having a conscience. In contrast hereto, the second theory (“helper theory” locates the evolutionary origins of conscience on the battlefield of the parent- offspring conflict through intrafamilial demands for altruism. Functions of conscience, and thus human morality in a narrower sense, evolved during the transition of hominines to cooperative breeding and the novel helper conflict emerging through this evolution. The “helper theory” of the evolution of conscience can resolve some of the theoretical and empirical inconsistencies of the conventional “navigator theory”, in particular, the contradiction between the consequentialistic regulation of altruistic behavior and the non-consequentialistic nature of the judgment of conscience. And in contrast to the “navigator theory”, it is compatible with the observation that behavior guided by a conscience is not infrequently disastrous for one’s own fitness outcome.

  3. Why Flavins Are not Competitors of Chlorophyll in the Evolution of Biological Converters of Solar Energy

    Science.gov (United States)

    Kritsky, Mikhail S.; Telegina, Taisiya A.; Vechtomova, Yulia L.; Buglak, Andrey A.

    2013-01-01

    Excited flavin molecules can photocatalyze reactions, leading to the accumulation of free energy in the products, and the data accumulated through biochemical experiments and by modeling prebiological processes suggest that flavins were available in the earliest stages of evolution. Furthermore, model experiments have shown that abiogenic flavin conjugated with a polyamino acid matrix, a pigment that photocatalyzes the phosphorylation of ADP to form ATP, could have been present in the prebiotic environment. Indeed, excited flavin molecules play key roles in many photoenzymes and regulatory photoreceptors, and the substantial structural differences between photoreceptor families indicate that evolution has repeatedly used flavins as chromophores for photoreceptor proteins. Some of these photoreceptors are equipped with a light-harvesting antenna, which transfers excitation energy to chemically reactive flavins in the reaction center. The sum of the available data suggests that evolution could have led to the formation of a flavin-based biological converter to convert light energy into energy in the form of ATP. PMID:23271372

  4. Why Flavins Are not Competitors of Chlorophyll in the Evolution of Biological Converters of Solar Energy

    Directory of Open Access Journals (Sweden)

    Mikhail S. Kritsky

    2012-12-01

    Full Text Available Excited flavin molecules can photocatalyze reactions, leading to the accumulation of free energy in the products, and the data accumulated through biochemical experiments and by modeling prebiological processes suggest that flavins were available in the earliest stages of evolution. Furthermore, model experiments have shown that abiogenic flavin conjugated with a polyamino acid matrix, a pigment that photocatalyzes the phosphorylation of ADP to form ATP, could have been present in the prebiotic environment. Indeed, excited flavin molecules play key roles in many photoenzymes and regulatory photoreceptors, and the substantial structural differences between photoreceptor families indicate that evolution has repeatedly used flavins as chromophores for photoreceptor proteins. Some of these photoreceptors are equipped with a light-harvesting antenna, which transfers excitation energy to chemically reactive flavins in the reaction center. The sum of the available data suggests that evolution could have led to the formation of a flavin-based biological converter to convert light energy into energy in the form of ATP.

  5. Why flavins are not competitors of chlorophyll in the evolution of biological converters of solar energy.

    Science.gov (United States)

    Kritsky, Mikhail S; Telegina, Taisiya A; Vechtomova, Yulia L; Buglak, Andrey A

    2012-01-01

    Excited flavin molecules can photocatalyze reactions, leading to the accumulation of free energy in the products, and the data accumulated through biochemical experiments and by modeling prebiological processes suggest that flavins were available in the earliest stages of evolution. Furthermore, model experiments have shown that abiogenic flavin conjugated with a polyamino acid matrix, a pigment that photocatalyzes the phosphorylation of ADP to form ATP, could have been present in the prebiotic environment. Indeed, excited flavin molecules play key roles in many photoenzymes and regulatory photoreceptors, and the substantial structural differences between photoreceptor families indicate that evolution has repeatedly used flavins as chromophores for photoreceptor proteins. Some of these photoreceptors are equipped with a light-harvesting antenna, which transfers excitation energy to chemically reactive flavins in the reaction center. The sum of the available data suggests that evolution could have led to the formation of a flavin-based biological converter to convert light energy into energy in the form of ATP. PMID:23271372

  6. A hypothesis on the biological origins and social evolution of music and dance.

    Science.gov (United States)

    Wang, Tianyan

    2015-01-01

    The origins of music and musical emotions is still an enigma, here I propose a comprehensive hypothesis on the origins and evolution of music, dance, and speech from a biological and sociological perspective. I suggest that every pitch interval between neighboring notes in music represents corresponding movement pattern through interpreting the Doppler effect of sound, which not only provides a possible explanation for the transposition invariance of music, but also integrates music and dance into a common form-rhythmic movements. Accordingly, investigating the origins of music poses the question: why do humans appreciate rhythmic movements? I suggest that human appreciation of rhythmic movements and rhythmic events developed from the natural selection of organisms adapting to the internal and external rhythmic environments. The perception and production of, as well as synchronization with external and internal rhythms are so vital for an organism's survival and reproduction, that animals have a rhythm-related reward and emotion (RRRE) system. The RRRE system enables the appreciation of rhythmic movements and events, and is integral to the origination of music, dance and speech. The first type of rewards and emotions (rhythm-related rewards and emotions, RRREs) are evoked by music and dance, and have biological and social functions, which in turn, promote the evolution of music, dance and speech. These functions also evoke a second type of rewards and emotions, which I name society-related rewards and emotions (SRREs). The neural circuits of RRREs and SRREs develop in species formation and personal growth, with congenital and acquired characteristics, respectively, namely music is the combination of nature and culture. This hypothesis provides probable selection pressures and outlines the evolution of music, dance, and speech. The links between the Doppler effect and the RRREs and SRREs can be empirically tested, making the current hypothesis scientifically

  7. Structure and functions of water-membrane interfaces and their role in proto-biological evolution

    Science.gov (United States)

    Pohorille, A.; Wilson, M.; Macelroy, R. D.

    1991-01-01

    Among the most important developments in proto-biological evolution was the emergence of membrane-like structures. These are formed by spontaneous association of relatively simple amphiphilic molecules that would have been readily available in the primordial environment. The resulting interfacial regions between water and nonpolar interior of the membrane have several properties which made them uniquely suitable for promoting subsequent evolution. They can (1) selectively attract organic material and mediate its transport, (2) serve as simple catalysts for chemical reactions, and (3) promote the formation of trans-membrane electrical and chemical gradients which could provide energy sources for proto-cells. Understanding the structure of interfaces, their interactions with organic molecules and molecular mechanisms of their functions is an essential step to understanding proto-biological evolution. In our computer simulation studies, we showed that the structure of water at interfaces with nonpolar media is significantly different from that in the bulk. In particular, the average surface dipole density points from the vapor to the liquid. As a result, negative ions can approach the interface more easily than positive ions. Amphiphilic molecules composed of hydrocarbon conjugated rings and polar substituents (e.g., phenol) assume at the interface rigid orientations in which polar groups are buried in water while hydrocarbon parts are located in the nonpolar environment. These orientational differences are of special interest in connection with the ability of some of these molecules to efficiently absorb photons. Flexible molecules with polar substituents often adopt at interfaces conformations different from those in the bulk aquaeous solution and in the gas phase. As a result, in many instances both specificity and kinetics of chemical reactions in which these molecules can participate is modified by the presence of surfaces. Of special interest is the mechanism by

  8. A hypothesis on the biological origins and social evolution of music and dance

    Directory of Open Access Journals (Sweden)

    Tianyan eWang

    2015-02-01

    Full Text Available The origins of music and musical emotions is still an enigma, here I propose a comprehensive hypothesis on the origins and evolution of music, dance and speech from a biological and sociological perspective. I suggest that every pitch interval between neighboring notes in music represents corresponding movement pattern through interpreting the Doppler effect of sound, which not only provides a possible explanation to the transposition invariance of music, but also integrates music and dance into a common form—rhythmic movements. Accordingly, investigating the origins of music poses the question: why do humans appreciate rhythmic movements? I suggest that human appreciation of rhythmic movements and rhythmic events developed from the natural selection of organisms adapting to the internal and external rhythmic environments. The perception and production of, as well as synchronization with external and internal rhythms are so vital for an organism’s survival and reproduction, that animals have a rhythm-related reward and emotion (RRRE system. The RRRE system enables the appreciation of rhythmic movements and events, and is integral to the origination of music, dance and speech. The first type of rewards and emotions (rhythm-related rewards and emotions, RRREs are evoked by music and dance, and have biological and social functions, which in turn, promote the evolution of music, dance and speech. These functions also evoke a second type of rewards and emotions, which I name society-related rewards and emotions (SRREs. The neural circuits of RRREs and SRREs develop in species formation and personal growth, with congenital and acquired characteristics, respectively, namely music is the combination of nature and culture. This hypothesis provides probable selection pressures and outlines the evolution of music, dance and speech. The links between the Doppler effect and the RRREs and SRREs can be empirically tested, making the current hypothesis

  9. Evolution and personal religious belief: Christian biology-related majors' search for reconciliation at a Christian university

    Science.gov (United States)

    Winslow, Mark William

    The goal of this study was to explore how Christian biology-related majors at a Christian university perceive the apparent conflicts between their understanding of evolution and their religious beliefs, and how their faith, as a structural-developmental system for ordering and making meaning of the world, plays a role in the mediating process. This naturalistic study utilized a case study design of 15 participants specified as undergraduate biology-related majors or recent biology-related graduates from a midwestern Christian university who had completed an upper-level course on evolution. Data were collected through semi-structured interviews that investigated participants' faith and their views on creationism and evolution. Fowler's theory of faith development and Parks' model of college students' faith was extensively used. Additional data were collected through an Evolution Attitudes Survey and a position paper on evolution as an assignment in the evolution course. Data analysis revealed patterns that were organized into themes and sub-themes that were the major outcomes of the study. Most participants were raised to believe in creationism, but came to accept evolution through an extended process of evaluating the scientific evidence in support of evolution, negotiating the literalness of Genesis, recognizing evolution as a non-salvation issue, and observing professors as role models of Christians who accept evolution. Participants remained committed to their personal religious beliefs despite apprehension that accompanied the reconciliation process in accepting evolution. Most participants operated from the perspective that science and religion are separate and interacting domains. Faith played an important role in how participants reconciled their understanding of evolution and their personal religious beliefs. Participants who operated in conventional faith dismissed contentious issues or collapsed dichotomies in an effort to avoid ambiguity and perceived

  10. The role of biology in planetary evolution: cyanobacterial primary production in low-oxygen Proterozoic oceans.

    Science.gov (United States)

    Hamilton, Trinity L; Bryant, Donald A; Macalady, Jennifer L

    2016-02-01

    Understanding the role of biology in planetary evolution remains an outstanding challenge to geobiologists. Progress towards unravelling this puzzle for Earth is hindered by the scarcity of well-preserved rocks from the Archean (4.0 to 2.5 Gyr ago) and Proterozoic (2.5 to 0.5 Gyr ago) Eons. In addition, the microscopic life that dominated Earth's biota for most of its history left a poor fossil record, consisting primarily of lithified microbial mats, rare microbial body fossils and membrane-derived hydrocarbon molecules that are still challenging to interpret. However, it is clear from the sulfur isotope record and other geochemical proxies that the production of oxygen or oxidizing power radically changed Earth's surface and atmosphere during the Proterozoic Eon, pushing it away from the more reducing conditions prevalent during the Archean. In addition to ancient rocks, our reconstruction of Earth's redox evolution is informed by our knowledge of biogeochemical cycles catalysed by extant biota. The emergence of oxygenic photosynthesis in ancient cyanobacteria represents one of the most impressive microbial innovations in Earth's history, and oxygenic photosynthesis is the largest source of O2 in the atmosphere today. Thus the study of microbial metabolisms and evolution provides an important link between extant biota and the clues from the geologic record. Here, we consider the physiology of cyanobacteria (the only microorganisms capable of oxygenic photosynthesis), their co-occurrence with anoxygenic phototrophs in a variety of environments and their persistence in low-oxygen environments, including in water columns as well as mats, throughout much of Earth's history. We examine insights gained from both the rock record and cyanobacteria presently living in early Earth analogue ecosystems and synthesize current knowledge of these ancient microbial mediators in planetary redox evolution. Our analysis supports the hypothesis that anoxygenic photosynthesis

  11. A non-linear irreversible thermodynamic perspective on organic pigment proliferation and biological evolution

    CERN Document Server

    Michaelian, Karo

    2013-01-01

    The most important thermodynamic work performed by life today is the dissipation of the solar photon flux into heat through organic pigments in water. From this thermodynamic perspective, biological evolution is thus just the dispersal of organic pigments and water throughout Earth's surface, while adjusting the gases of Earth's atmosphere to allow the most intense part of the solar spectrum to penetrate the atmosphere and reach the surface to be intercepted by these pigments. The covalent bonding of atoms in organic pigments provides excited levels compatible with the energies of these photons. Internal conversion through vibrational relaxation to the ground state of these excited molecules when in water leads to rapid dissipation of the solar photons into heat, and this is the major source of entropy production on Earth. A non-linear irreversible thermodynamic analysis shows that the proliferation of organic pigments on Earth is a direct consequence of the pigments catalytic properties in dissipating the so...

  12. Design in nature how the constructal law governs evolution in biology, physics, technology, and social organization

    CERN Document Server

    Bejan, Adrian

    2013-01-01

    In this groundbreaking book, Adrian Bejan takes the recurring patterns in nature—trees, tributaries, air passages, neural networks, and lightning bolts—and reveals how a single principle of physics, the constructal law, accounts for the evolution of these and many other designs in our world. Everything—from biological life to inanimate systems—generates shape and structure and evolves in a sequence of ever-improving designs in order to facilitate flow. River basins, cardiovascular systems, and bolts of lightning are very efficient flow systems to move a current—of water, blood, or electricity. Likewise, the more complex architecture of animals evolve to cover greater distance per unit of useful energy, or increase their flow across the land. Such designs also appear in human organizations, like the hierarchical “flowcharts” or reporting structures in corporations and political bodies. All are governed by the same principle, known as the constructal law, and configure and reconfigure themselves...

  13. Geomagnetic polarity reversals as a mechanism for the punctuated equilibrium model of biological evolution

    International Nuclear Information System (INIS)

    In contrast to what is predicted by classical Darwinian theory (phyletic gradualism), the fossil record typically displays a pattern of relatively sudden, dramatic changes as detailed by Eldregde and Gould's model of punctuated equilibrium. Evolutionary biologists have been at a loss to explain the ultimate source of the new mutations that drive evolution. One hypothesis holds that the abrupt speciation seen in the punctuated equilibrium model is secondary to an increased mutation rate resulting from periodically increased levels of ionizing radiation on the Earth's surface. Sporadic geomagnetic pole reversals, occurring every few million years on the average, are accompanied by alterations in the strength of the Earth's magnetic field and magnetosphere. This diminution may allow charged cosmic radiation to bombard Earth with less attenuation, thereby resulting in increased mutation rates. This episodic fluctuation in the magnetosphere is an attractive mechanism for the observed fossil record. Selected periods and epochs of geologic history for which data was available were reviewed for both geomagnetic pole reversal history and fossil record. Anomalies in either were scrutinized in greater depth and correlations were made. A 35 million year span (118-83 Ma) was identified during the Early/Middle Cretaceous period that was devoid of geomagnetic polarity reversals(the Cretaceous normal superchron). Examination of the fossil record (including several invertebrate and vertebrate taxons) during the Cretaceous normal superchron does not reveal any significant gap or slowing of speciation. Although increased terrestrial radiation exposure due to a diminution of the Earth's magnetosphere caused by a reversal of geomagnetic polarity is an attractive explanation for the mechanism of punctuated equilibrium, our investigation suggests that such polarity reversals cannot fully provide the driving force behind biological evolution. Further research is required to determine if

  14. The common extremalities in biology and physics maximum energy dissipation principle in chemistry, biology, physics and evolution

    CERN Document Server

    Moroz, Adam

    2011-01-01

    This book is the first unified systemic description of dissipative phenomena, taking place in biology, and non-dissipative (conservative) phenomena, which is more relevant to physics. Fully updated and revised, this new edition extends our understanding of nonlinear phenomena in biology and physics from the extreme / optimal perspective. The first book to provide understanding of physical phenomena from a biological perspective and biological phenomena from a physical perspectiveDiscusses emerging fields and analysisProvides examples

  15. The role of external pressure and support on teacher choices related to evolution curriculum in the secondary biology classroom

    Science.gov (United States)

    Oschman, Scot

    The scientific community strongly and virtually universally supports the teaching of biological evolution in our public schools. However, there are many in the general public who object to the teaching of biological evolution in our nation's science classrooms. Groups such as Answers in Genesis and the Discovery Institute, along with parents, students, school boards, and school administrators are alleged by many in the scientific and science education communities to be pressuring teachers in a variety of ways regarding the teaching of evolution. The purpose of this study was to examine the sources of, extent of, and ways in which science teachers deal with external influences that attempt to alter their science curriculum related to the teaching of the theory of biological evolution in order to support it, deemphasize it or remove it from their classrooms. It also attempted to determine the impact these outside influences have on evolution education in the classroom. Internal influences were examined in order to ascertain other possible reasons why teachers might or might not de-emphasize, omit, or teach evidence contrary to evolution. Two thousand cover letters were sent out to high school biology teachers selected at random from three states in the U.S. Registry of Teachers, directing them to a web site where they could complete the questionnaire online. One hundred seventy eight teachers responded to the survey. The statistical analyses used in this study to examine the results included analysis of variance (ANOVA), independent samples t tests for means comparisons, as well as a variety of descriptive statistics. This study found that 59% of the teachers who responded had experienced some form of pressure related to their evolution curriculum, and that the majority of this pressure came from students, groups or individuals not affiliated with their school district, and parents. The most common manifestations of pressure were to teach that evolution was "only" a

  16. The Towuti Drilling Project: paleoenvironments, biological evolution, and geomicrobiology of a tropical Pacific lake

    Science.gov (United States)

    Russell, James M.; Bijaksana, Satria; Vogel, Hendrik; Melles, Martin; Kallmeyer, Jens; Ariztegui, Daniel; Crowe, Sean; Fajar, Silvia; Hafidz, Abdul; Haffner, Doug; Hasberg, Ascelina; Ivory, Sarah; Kelly, Christopher; King, John; Kirana, Kartika; Morlock, Marina; Noren, Anders; O'Grady, Ryan; Ordonez, Luis; Stevenson, Janelle; von Rintelen, Thomas; Vuillemin, Aurele; Watkinson, Ian; Wattrus, Nigel; Wicaksono, Satrio; Wonik, Thomas; Bauer, Kohen; Deino, Alan; Friese, André; Henny, Cynthia; Imran; Marwoto, Ristiyanti; Ode Ngkoimani, La; Nomosatryo, Sulung; Ode Safiuddin, La; Simister, Rachel; Tamuntuan, Gerald

    2016-07-01

    The Towuti Drilling Project (TDP) is an international research program, whose goal is to understand long-term environmental and climatic change in the tropical western Pacific, the impacts of geological and environmental changes on the biological evolution of aquatic taxa, and the geomicrobiology and biogeochemistry of metal-rich, ultramafic-hosted lake sediments through the scientific drilling of Lake Towuti, southern Sulawesi, Indonesia. Lake Towuti is a large tectonic lake at the downstream end of the Malili lake system, a chain of five highly biodiverse lakes that are among the oldest lakes in Southeast Asia. In 2015 we carried out a scientific drilling program on Lake Towuti using the International Continental Scientific Drilling Program (ICDP) Deep Lakes Drilling System (DLDS). We recovered a total of ˜ 1018 m of core from 11 drilling sites with water depths ranging from 156 to 200 m. Recovery averaged 91.7 %, and the maximum drilling depth was 175 m below the lake floor, penetrating the entire sedimentary infill of the basin. Initial data from core and borehole logging indicate that these cores record the evolution of a highly dynamic tectonic and limnological system, with clear indications of orbital-scale climate variability during the mid- to late Pleistocene.

  17. Reconstructing Anaximander's biological model unveils a theory of evolution akin to Darwin's, though centuries before the birth of science.

    Science.gov (United States)

    Trevisanato, Siro Igino

    2016-08-01

    Anaximander's fragments on biology report a theory of evolution, which, unlike the development of other biological systems in the ancient Aegean, is naturalistic and is not based on metaphysics. According to Anaximander, evolution affected all living beings, including humans. The first biological systems formed in an aquatic environment, and were encased in a rugged and robust envelope. Evolution progressed with modifications that enabled the formation of more dynamic biological systems. For instance, after reaching land, the robust armors around aquatic beings dried up, and became brittle, This led to the loss of the armor and the development of more mobile life forms. Anaximander's theory combines observations of animals with speculations, and as such mirrors the more famous theory of evolution by Charles Darwin expressed 24 centuries later. The poor reception received by Anaximander's model in his time, illustrates a zeitgeist that would explain the contemporary lag phase in the development of biology and, as a result, medicine, in the ancient western world. PMID:27598953

  18. [Evolution of biologicals in inflammation medicine--biosimilars in gastroenterology, rheumatology and dermatology].

    Science.gov (United States)

    Schreiber, S; Luger, T; Mittendorf, T; Mrowietz, U; Müller-Ladner, U; Schröder, J; Stallmach, A; Bokemeyer, B

    2014-11-01

    Biologicals revolutionized the therapy of chronic inflammatory diseases in gastroenterology, rheumatology and dermatology in the last decade. The first generation biologicals mainly targeted against the pro-inflammatory cytokine TNF-α. The evolution of these therapies in the last years led to the development of new antibodies and to the admission of first generation "generic" biologics - the biosimilars. Biosimilars are not a fundamental new pharmacological development for existing substances, however they have the potential to lead to enormous cost savings in healthcare without reducing the level of care for patients. Biosimilars are not identical with the originator, but in an extensive biosimilarity exercise including analytical, preclinical and comparative clinical studies it was shown that the biosimilars could demonstrate comparability in all relevant aspects with the originator.In September 2013, the Infliximab biosimilars (Inflectra(®), Remsina(®)) were the first biosimilars for monoclonal antibodies to be authorized by the EMA for use in the European Union. By demonstrating the therapeutic similarity only in one indication (rheumatoid arthritis) the EMA agreed with an extrapolation also to all approved indications of the originator. This could be a relevant problem in clinical practice. Therefore, comparative studies with the originator are required in all approved indications.After expiration of the national patent protection in beginning of 2015, the infliximab biosimilars will be launched on the market in Germany and will be part of the therapeutic arsenal in gastroenterology, rheumatology and dermatology. Interchangeability (Switching) of biosimilars with the originator will be subject of an important discussion with the health care providers. Regardless of the biosimilars EMA-approval, several potential problems (efficacy, extrapolation, switching, long-term safety) should be the topic of intensive long-term registries in the future. PMID:25390629

  19. Three Decades of Anti-Evolution Campaign and Its Results: Turkish Undergraduates' Acceptance and Understanding of the Biological Evolution Theory

    Science.gov (United States)

    Peker, Deniz; Comert, Gulsum Gul; Kence, Aykut

    2010-01-01

    Even though in the early years of the Republic of Turkey Darwin's theory of evolution was treated as a scientific theory and taught fairly in schools, despite all the substantial evidence accumulated supporting the theory of evolution since then, Darwin and his ideas today have been scorned by curriculum and education policy makers. Furthermore,…

  20. Effects of an Educational Experience Incorporating an Inventory of Factors Potentially Influencing Student Acceptance of Biological Evolution

    Science.gov (United States)

    Wiles, Jason R.; Alters, Brian

    2011-01-01

    This investigation provides an extensive review of scientific, religious, and otherwise non-scientific factors that may influence student acceptance of biological evolution. We also measure the extent to which students' levels of acceptance changed following an educational experience designed to address an inclusive inventory of factors identified…

  1. A Comparison of Massachusetts and Texas High School Biology Teachers' Attitudes towards the Teaching of Evolution

    Science.gov (United States)

    Howarth, Richard T.

    2012-01-01

    Darwin's theory of evolution by natural selection is considered to be the unifying theory for all life sciences (American Association for the Advancement of Science, AAAS, 1990; National Academy of Sciences, 1998; National Research Council, NRC, 1996; National Science Teachers Association, NSTA, 2010a) and as such, the biology topic has been…

  2. Recent advances in alveolar biology: evolution and function of alveolar proteins.

    Science.gov (United States)

    Orgeig, Sandra; Hiemstra, Pieter S; Veldhuizen, Edwin J A; Casals, Cristina; Clark, Howard W; Haczku, Angela; Knudsen, Lars; Possmayer, Fred

    2010-08-31

    This review is focused on the evolution and function of alveolar proteins. The lung faces physical and environmental challenges, due to changing pressures/volumes and foreign pathogens, respectively. The pulmonary surfactant system is integral in protecting the lung from these challenges via two groups of surfactant proteins - the small molecular weight hydrophobic SPs, SP-B and -C, that regulate interfacial adsorption of the lipids, and the large hydrophilic SPs, SP-A and -D, which are surfactant collectins capable of inhibiting foreign pathogens. Further aiding pulmonary host defence are non-surfactant collectins and antimicrobial peptides that are expressed across the biological kingdoms. Linking to the first symposium session, which emphasised molecular structure and biophysical function of surfactant lipids and proteins, this review begins with a discussion of the role of temperature and hydrostatic pressure in shaping the evolution of SP-C in mammals. Transitioning to the role of the alveolus in innate host defence we discuss the structure, function and regulation of antimicrobial peptides, the defensins and cathelicidins. We describe the recent discovery of novel avian collectins and provide evidence for their role in preventing influenza infection. This is followed by discussions of the roles of SP-A and SP-D in mediating host defence at the alveolar surface and in mediating inflammation and the allergic response of the airways. Finally we discuss the use of animal models of lung disease including knockouts to develop an understanding of the role of these proteins in initiating and/or perpetuating disease with the aim of developing new therapeutic strategies. PMID:20433956

  3. Once upon Multivariate Analyses: When They Tell Several Stories about Biological Evolution.

    Directory of Open Access Journals (Sweden)

    Sabrina Renaud

    Full Text Available Geometric morphometrics aims to characterize of the geometry of complex traits. It is therefore by essence multivariate. The most popular methods to investigate patterns of differentiation in this context are (1 the Principal Component Analysis (PCA, which is an eigenvalue decomposition of the total variance-covariance matrix among all specimens; (2 the Canonical Variate Analysis (CVA, a.k.a. linear discriminant analysis (LDA for more than two groups, which aims at separating the groups by maximizing the between-group to within-group variance ratio; (3 the between-group PCA (bgPCA which investigates patterns of between-group variation, without standardizing by the within-group variance. Standardizing within-group variance, as performed in the CVA, distorts the relationships among groups, an effect that is particularly strong if the variance is similarly oriented in a comparable way in all groups. Such shared direction of main morphological variance may occur and have a biological meaning, for instance corresponding to the most frequent standing genetic variation in a population. Here we undertake a case study of the evolution of house mouse molar shape across various islands, based on the real dataset and simulations. We investigated how patterns of main variance influence the depiction of among-group differentiation according to the interpretation of the PCA, bgPCA and CVA. Without arguing about a method performing 'better' than another, it rather emerges that working on the total or between-group variance (PCA and bgPCA will tend to put the focus on the role of direction of main variance as line of least resistance to evolution. Standardizing by the within-group variance (CVA, by dampening the expression of this line of least resistance, has the potential to reveal other relevant patterns of differentiation that may otherwise be blurred.

  4. Once upon Multivariate Analyses: When They Tell Several Stories about Biological Evolution.

    Science.gov (United States)

    Renaud, Sabrina; Dufour, Anne-Béatrice; Hardouin, Emilie A; Ledevin, Ronan; Auffray, Jean-Christophe

    2015-01-01

    Geometric morphometrics aims to characterize of the geometry of complex traits. It is therefore by essence multivariate. The most popular methods to investigate patterns of differentiation in this context are (1) the Principal Component Analysis (PCA), which is an eigenvalue decomposition of the total variance-covariance matrix among all specimens; (2) the Canonical Variate Analysis (CVA, a.k.a. linear discriminant analysis (LDA) for more than two groups), which aims at separating the groups by maximizing the between-group to within-group variance ratio; (3) the between-group PCA (bgPCA) which investigates patterns of between-group variation, without standardizing by the within-group variance. Standardizing within-group variance, as performed in the CVA, distorts the relationships among groups, an effect that is particularly strong if the variance is similarly oriented in a comparable way in all groups. Such shared direction of main morphological variance may occur and have a biological meaning, for instance corresponding to the most frequent standing genetic variation in a population. Here we undertake a case study of the evolution of house mouse molar shape across various islands, based on the real dataset and simulations. We investigated how patterns of main variance influence the depiction of among-group differentiation according to the interpretation of the PCA, bgPCA and CVA. Without arguing about a method performing 'better' than another, it rather emerges that working on the total or between-group variance (PCA and bgPCA) will tend to put the focus on the role of direction of main variance as line of least resistance to evolution. Standardizing by the within-group variance (CVA), by dampening the expression of this line of least resistance, has the potential to reveal other relevant patterns of differentiation that may otherwise be blurred. PMID:26192946

  5. An Aristotelian Account of Evolution and the Contemporary Philosophy of Biology

    Directory of Open Access Journals (Sweden)

    Mariusz Tabaczek

    2015-05-01

    Full Text Available The anti-reductionist character of the recent philosophy of biology and the dynamic development of the science of emergent properties prove that the time is ripe to reintroduce the thought of Aristotle, the first advocate of a “top-down” approach in life-sciences, back into the science/philosophy debate. His philosophy of nature provides profound insights particularly in the context of the contemporary science of evolution, which is still struggling with the questions of form (species, teleology, and the role of chance in evolutionary processes. However, although Aristotle is referenced in the evolutionary debate, a thorough analysis of his theory of hylomorphism and the classical principle of causality which he proposes is still needed in this exchange. Such is the main concern of the first part of the present article which shows Aristotle’s metaphysics of substance as an open system, ready to incorporate new hypothesis of modern and contemporary science. The second part begins with the historical exploration of the trajectory from Darwin to Darwinism regarded as a metaphysical position. This exploration leads to an inquiry into the central topics of the present debate in the philosophy of evolutionary biology. It shows that Aristotle’s understanding of species, teleology, and chance – in the context of his fourfold notion of causality – has a considerable explanatory power which may enhance our understanding of the nature of evolutionary processes. This fact may inspire, in turn, a retrieval of the classical theology of divine action, based on Aristotelian metaphysics, in the science/theology dialogue. The aim of the present article is to prepare a philosophical ground for such project.

  6. Superhydrophobic hierarchically structured surfaces in biology: evolution, structural principles and biomimetic applications.

    Science.gov (United States)

    Barthlott, W; Mail, M; Neinhuis, C

    2016-08-01

    A comprehensive survey of the construction principles and occurrences of superhydrophobic surfaces in plants, animals and other organisms is provided and is based on our own scanning electron microscopic examinations of almost 20 000 different species and the existing literature. Properties such as self-cleaning (lotus effect), fluid drag reduction (Salvinia effect) and the introduction of new functions (air layers as sensory systems) are described and biomimetic applications are discussed: self-cleaning is established, drag reduction becomes increasingly important, and novel air-retaining grid technology is introduced. Surprisingly, no evidence for lasting superhydrophobicity in non-biological surfaces exists (except technical materials). Phylogenetic trees indicate that superhydrophobicity evolved as a consequence of the conquest of land about 450 million years ago and may be a key innovation in the evolution of terrestrial life. The approximate 10 million extant species exhibit a stunning diversity of materials and structures, many of which are formed by self-assembly, and are solely based on a limited number of molecules. A short historical survey shows that bionics (today often called biomimetics) dates back more than 100 years. Statistical data illustrate that the interest in biomimetic surfaces is much younger still. Superhydrophobicity caught the attention of scientists only after the extreme superhydrophobicity of lotus leaves was published in 1997. Regrettably, parabionic products play an increasing role in marketing.This article is part of the themed issue 'Bioinspired hierarchically structured surfaces for green science'. PMID:27354736

  7. The virtue of innovation: innovation through the lenses of biological evolution

    Science.gov (United States)

    Kell, Douglas B.; Lurie-Luke, Elena

    2015-01-01

    We rehearse the processes of innovation and discovery in general terms, using as our main metaphor the biological concept of an evolutionary fitness landscape. Incremental and disruptive innovations are seen, respectively, as successful searches carried out locally or more widely. They may also be understood as reflecting evolution by mutation (incremental) versus recombination (disruptive). We also bring a platonic view, focusing on virtue and memory. We use ‘virtue’ as a measure of efforts, including the knowledge required to come up with disruptive and incremental innovations, and ‘memory’ as a measure of their lifespan, i.e. how long they are remembered. Fostering innovation, in the evolutionary metaphor, means providing the wherewithal to promote novelty, good objective functions that one is trying to optimize, and means to improve one's knowledge of, and ability to navigate, the landscape one is searching. Recombination necessarily implies multi- or inter-disciplinarity. These principles are generic to all kinds of creativity, novel ideas formation and the development of new products and technologies. PMID:25505138

  8. The biological evolution of guilt, shame and anxiety: A new theory of negative legacy emotions.

    Science.gov (United States)

    Breggin, Peter R

    2015-07-01

    Human beings are the most social and the most violent creatures on Earth. The combination of cooperation and aggression enabled us to dominate our ecosystem. However, the existence of violent impulses would have made it difficult or impossible for humans to live in close-knit families and clans without destroying each other. Nature's answer was the development of guilt, shame and anxiety-internal emotional inhibitions or restraints specifically against aggressive self-assertion within the family and other close relationships. The theory of negative legacy emotions proposes the first unitary concept for the biopsychosocial function of guilt, shame and anxiety, and seeks their origin in biological evolution and natural selection. Natural selection favored individuals with built-in emotional restraints that reduced conflicts within their family and tribal unit, optimizing their capacity to survive and reproduce within the protection of their small, intimate societies, while maintaining their capacity for violence against outsiders. Unfortunately, these negative legacy emotions are rudimentary and often ineffective in their psychosocial and developmental function. As a result, they produce many unintended untoward effects, including the frequent breakdown of restraints in the family and the uninhibited unleashing of violence against outsiders. PMID:25890689

  9. Providing vertical coherence in explanations and promoting reasoning across levels of biological organization when teaching evolution

    Science.gov (United States)

    Jördens, Janina; Asshoff, Roman; Kullmann, Harald; Hammann, Marcus

    2016-04-01

    Students' explanations of biological phenomena are frequently characterized by disconnects between levels and confusion of levels. The purpose of this research is to investigate the effects of a hands-on lab activity that aims at fostering the ability to reason across levels. A total of 197 students (18 years of age) participated in a randomized, pre-post-test design study. Students in the experimental group engaged in a lab activity focused on artificial selection and designed to demonstrate how selection affects both phenotypes and genotypes. In contrast, the lab activity in the comparison group focused on phenotype alone. Data sources for the study included pre-tests of basic concepts in genetics and evolution and two post-test items requiring the students to reproduce and apply their knowledge about artificial selection. The findings indicated that the lab activity which allowed students to explore the interplay between different levels, provided vertical coherence and enhanced students' ability to explain evolutionary change in both reproduction and transfer items. In contrast, the lab activity in the comparison group failed to do so, and most students did not improve their ability to explain evolutionary change. Implications for instruction and recommendations for further research are discussed in light of these findings.

  10. Jupiter and Planet Earth. [planetary and biological evolution and natural satellites

    Science.gov (United States)

    1975-01-01

    The evolution of Jupiter and Earth are discussed along with their atmospheres, the radiation belts around both planets, natural satellites, the evolution of life, and the Pioneer 10. Educational study projects are also included.

  11. Evolution of a physical and biological front from upwelling to relaxation

    Science.gov (United States)

    Zhang, Yanwu; Bellingham, James G.; Ryan, John P.; Godin, Michael A.

    2015-10-01

    Fronts influence the structure and function of coastal marine ecosystems. Due to the complexity and dynamic nature of coastal environments and the small scales of frontal gradient zones, frontal research is difficult. To advance this challenging research we developed a method enabling an autonomous underwater vehicle (AUV) to detect and track fronts, thereby providing high-resolution observations in the moving reference frame of the front itself. This novel method was applied to studying the evolution of a frontal zone in the coastal upwelling environment of Monterey Bay, California, through a period of variability in upwelling intensity. Through 23 frontal crossings in four days, the AUV detected the front using real-time analysis of vertical thermal stratification to identify water types and the front between them, and the vehicle tracked the front as it moved more than 10 km offshore. The physical front coincided with a biological front between strongly stratified phytoplankton-enriched water inshore of the front, and weakly stratified phytoplankton-poor water offshore of the front. While stratification remained a consistent identifier, conditions on both sides of the front changed rapidly as regional circulation responded to relaxation of upwelling winds. The offshore water type transitioned from relatively cold and saline upwelled water to relatively warm and fresh coastal transition zone water. The inshore water type exhibited an order of magnitude increase in chlorophyll concentrations and an associated increase in oxygen and decrease in nitrate. It also warmed and freshened near the front, consistent with the cross-frontal exchange that was detected in the high-resolution AUV data. AUV-observed cross-frontal exchanges beneath the surface manifestation of the front emphasize the importance of AUV synoptic water column surveys in the frontal zone.

  12. An analysis of factors influencing the teaching of evolution and creation by Arizona high school biology teachers

    Science.gov (United States)

    Jorstad, Susan

    2002-09-01

    This study examined the amount of emphasis given by Arizona high school biology teachers to the topics of evolutionary theory and special creation, as explanations for the origin and diversity of life on earth. A questionnaire was mailed to all Arizona public high school biology teachers in March of 2000, to gather data on teachers' classroom practices and attitudes towards evolution and creation, information on teachers' educational and professional backgrounds, their religious preferences, and any perceptions of pressure regarding the teaching of evolution or creation from outside sources. Sixty-five percent (final n = 419) of the questionnaires were returned. Analysis confirmed that, while a strong majority (96%) of Arizona teachers gave some coverage to evolutionary theory, a significant proportion (33%) reported fewer than three class periods per semester in which evolution was a major topic; 10% left it out entirely. Fourteen percent of the teachers reported that they gave moderate-to-strong emphasis to religious explanations of the origins and diversity of life. It was unclear whether this was presented as an alternative scientific theory, or as religion or philosophy. Between ten and thirty percent also rejected the scientific validity of evolutionary theory, rejected the evolution of humans from ape-like ancestors, thought that religious explanations should be taught as part of high school biology classes, or agreed that creationism has a valid scientific foundation. The amount of emphasis given evolution by a teacher correlated positively with teaching experience, number of college classes in evolutionary biology taken by the teacher, the amount of in-service training a teacher had had on teaching evolutionary theory, and age. It correlated negatively with membership in Conservative Christian religious denominations and with degree of religious fervor. Interestingly, the possession of a degree in biological sciences (e.g., versus a degree in education

  13. Stochastic many-body problems in ecology, evolution, neuroscience, and systems biology

    Science.gov (United States)

    Butler, Thomas C.

    Using the tools of many-body theory, I analyze problems in four different areas of biology dominated by strong fluctuations: The evolutionary history of the genetic code, spatiotemporal pattern formation in ecology, spatiotemporal pattern formation in neuroscience and the robustness of a model circadian rhythm circuit in systems biology. In the first two research chapters, I demonstrate that the genetic code is extremely optimal (in the sense that it manages the effects of point mutations or mistranslations efficiently), more than an order of magnitude beyond what was previously thought. I further show that the structure of the genetic code implies that early proteins were probably only loosely defined. Both the nature of early proteins and the extreme optimality of the genetic code are interpreted in light of recent theory [1] as evidence that the evolution of the genetic code was driven by evolutionary dynamics that were dominated by horizontal gene transfer. I then explore the optimality of a proposed precursor to the genetic code. The results show that the precursor code has only limited optimality, which is interpreted as evidence that the precursor emerged prior to translation, or else never existed. In the next part of the dissertation, I introduce a many-body formalism for reaction-diffusion systems described at the mesoscopic scale with master equations. I first apply this formalism to spatially-extended predator-prey ecosystems, resulting in the prediction that many-body correlations and fluctuations drive population cycles in time, called quasicycles. Most of these results were previously known, but were derived using the system size expansion [2, 3]. I next apply the analytical techniques developed in the study of quasi-cycles to a simple model of Turing patterns in a predator-prey ecosystem. This analysis shows that fluctuations drive the formation of a new kind of spatiotemporal pattern formation that I name "quasi-patterns." These quasi

  14. Structural calibration of the rates of amino acid evolution in a search for Darwin in drifting biological systems.

    Science.gov (United States)

    Toft, Christina; Fares, Mario A

    2010-10-01

    In the last two decades, many reports of proteins under positive selection have brought the neutral theory into question. However, the methods used to detect selection have ignored the evolvability of amino acids within proteins, which is fundamental to distinguishing positive selection from the relaxed constraints caused by genetic drift. Disentangling these two counterbalancing forces is essential to test the neutral theory. Here, we calibrate rates of amino acid divergence by using structural information from the full set of crystallized proteins in bacteria. In agreement with previous reports, we show that rates of amino acid evolution correlate negatively with the number of per-amino acid atomic interactions. Calibration of the rates of evolution allows identifying signatures of selection in biological systems that evolve under strong genetic drift, such as endosymbiotic bacteria. Application of this method identifies different rates and dynamics of evolution for highly connected amino acids in the structure compared with sparsely connected ones. We also unearth patterns of Darwinian selection in fundamental cellular proteins in endosymbiotic bacteria including the cochaperonin GroES, ribosomal proteins, proteins involved in cell cycle control, DNA-binding proteins, and proteins involved in DNA replication and repair. This is, to our knowledge, the first attempt to distinguish adaptive evolution from relaxed constraints in biological systems under genetic drift. PMID:20466746

  15. 50 Years of JBE: The Evolution of Biology as a School Subject

    Science.gov (United States)

    Jenkins, Edgar

    2016-01-01

    When the "Journal of Biological Education" was first published in 1967, biology was still very much the Cinderella of the three school sciences in many countries. Most selective secondary school biology courses readily betrayed their origins as an unconvincing coalition of botany and zoology. In the non-selective secondary modern…

  16. Nature of science conceptions, attitudes towards evolution and global climate change, and course achievement in an introductory biology course

    Science.gov (United States)

    Carter, Benjamin Elijah

    which variables accounted for the most variation, and those variables were analyzed using correlation tests, ANOVA, and ANCOVA to test for significant correlations and interaction effects. Changes in students' attitudes towards evolution and global climate change were both positively correlated with shifts in conceptions about the nature of science. Attitudes towards evolution were negatively correlated with religiosity. Knowledge of evolutionary science was positively correlated with attitudes towards evolution, but knowledge about GCC was not significantly correlated with attitudes towards GCC. The strongest correlates of GCC attitudes were political leanings. Findings support the hypothesis that a better understanding of NOS may lead to changes in attitudes towards politically contentious ideas that are not scientifically contentious. Though attitudes towards evolution correlated strongly and significantly with a number of other factors including knowledge of evolutionary science and religiosity, expected non-political correlates with attitudes towards GCC were absent. Giving students a good conception of the modern nature of science may lead to views that are closer to those of the scientific community. This study provides novel evidence of a linkage between student acceptance of evolution and attitudes towards GCC, i.e., NOS conceptions. We also found highly significant, positive relationships between student knowledge of evolution and attitudes toward evolution as well as between introductory biology course achievement and both pre- course acceptance of evolution and pre-course knowledge of evolution among students at Syracuse University, and assert that teachers who scant the teaching of evolution or who do not foster good attitudes toward evolution are not helping their students to prepare for success in science at the college level.

  17. The Biological “Invariant of Motion” vs. “Struggle for Life”? On the Possible Quantum Mechanical Origin and Evolution of Semiotic Controls in Biology

    Directory of Open Access Journals (Sweden)

    András Balázs

    2013-10-01

    Full Text Available A novel, alternative and deeper view to the “selfish gene” paradigm is presented, describable as the “selfish code” frame. Introducing it, we put forth a quantum mechanical algorithm as a new description of the intracellular protein synthetizing machinery. The successive steps of the algorithm are, tentatively, semiotic constraints of the well-known quantum mechanical molecular “internal measurement” type. It is proposed that this molecular algorithm mediates a quantum mechanical time reversed dynamics with a primordial special version of this latter molecular measurement type (“mixed measurement” as its origin. It is furthermore suggested that this intracellular regressive algorithmical dynamics is a component of biological “motion”, the other, strongly coupled component being the macroscopic phenotypic motion. The biological “invariant of motion” of this hierarchically coupled overall generalized dynamics is suggested to be the evolutionally converged invariant genetic code vocabulary. It forms, possibly, the underlying internal “driving force” of evolution, as being “struggle for life”.

  18. Articles selected by Faculty of 1000 Biology: genetically identical SNPs; detailed histone modification mapping; plant gene-expression diversity; photosynthesis gene evolution; ε-Proteobacteria diversity.

    OpenAIRE

    2005-01-01

    A selection of evaluations from Faculty of 1000 Biology covering genetically identical SNPs; detailed histone modification mapping; plant gene-expression diversity; photosynthesis gene evolution; ε-Proteobacteria diversity

  19. High School Biology Teachers' Knowledge Structure, Acceptance and Teaching of Evolution.

    Science.gov (United States)

    Rutledge, Michael L.; Mitchell, Melissa A.

    2002-01-01

    Determines teachers' conceptions of evolutionary theory using the technique of concept mapping. Discusses the methodology, the survey items, and concept map features. Makes specific recommendations for the teaching of evolution. (Contains 32 references.) (DDR)

  20. CONTINUOUS, AUTOMATED AND SIMULTANEOUS MEASUREMENT OF OXYGEN UPTAKE AND CARBON DIOXIDE EVOLUTION IN BIOLOGICAL SYSTEMS

    Science.gov (United States)

    Commercial respirometers are capable of continuously and automatically measuring oxygen uptake in bioreactors. A method for continuously and automatically measuring carbon dioxide evolution can be retrofitted to commercial respirometers. Continuous and automatic measurements of...

  1. TEMPORAL EVOLUTION OF SKELETAL REGENERATED TISSUE : WHAT CAN MECHANICAL INVESTIGATION ADD TO BIOLOGICAL?

    OpenAIRE

    Casanova, Remy; Mokoko, Didier; Pithioux, Martine; Pailler-Mattéi, Cyril; Zahouani, Hassan; Chabrand, Patrick

    2010-01-01

    The objective here was to experimentally characterise the temporal evolution of the structural and mechanical properties of large volume immature regenerated tissues. We studied these evolving tissues from their genesis in controlled mechanical conditions. We developed an animal model based on the periosteal properties leading to unloaded regenerated skeletal tissue. To characterize the temporal evolution of mechanical properties, we carried out indentation tests coupled with macroscopic exam...

  2. The Coverage of Human Evolution in High School Biology Textbooks in the 20th Century and in Current State Science Standards

    Science.gov (United States)

    Skoog, Gerald

    2005-01-01

    Efforts to eliminate or neutralize the coverage of evolution in high school biology textbooks in the United States have persisted with varying degrees of intensity and success since the 1920s. In particular, the coverage of human evolution has been impacted by these efforts. Evidence of the success of these efforts can be chronicled by the…

  3. Evolution of conformational changes in the dynamics of small biological molecules: a hybrid MD/RRK approach.

    Science.gov (United States)

    Segev, Elad; Grumbach, Mikael; Gerber, Robert Benny

    2006-11-14

    The dynamics of long timescale evolution of conformational changes in small biological molecules is described by a hybrid molecular dynamics/RRK algorithm. The approach employs classical trajectories for transitions between adjacent structures separated by a low barrier, and the classical statistical RRK approximation when the barrier involved is high. In determining the long-time dynamics from an initial structure to a final structure of interest, an algorithm is introduced for determining the most efficient pathways (sequence of the intermediate conformers). This method uses the Dijkstra algorithm for finding optimal paths on networks. Three applications of the method using an AMBER force field are presented: a detailed study of conformational transitions in a blocked valine dipeptide; a multiple reaction path study of the blocked valine tripeptide; and the evolution in time from the beta hairpin to alpha helix structure of a blocked alanine hexapeptide. Advantages and limitations of the method are discussed in light of the results. PMID:17066182

  4. Underlying Principles of Natural Selection in Network Evolution: Systems Biology Approach

    OpenAIRE

    Bor-Sen Chen; Wei-Sheng Wu

    2007-01-01

    Systems biology is a rapidly expanding field that integrates diverse areas of science such as physics, engineering, computer science, mathematics, and biology toward the goal of elucidating the underlying principles of hierarchical metabolic and regulatory systems in the cell, and ultimately leading to predictive understanding of cellular response to perturbations. Because post-genomics research is taking place throughout the tree of life, comparative approaches offer a way for combining data...

  5. Degrading organic micropollutants: The next challenge in the evolution of biological wastewater treatment processes

    OpenAIRE

    Naresh eSinghal; Octavio ePerez-Garcia

    2016-01-01

    Global water scarcity is driving the need for identifying new water source. Wastewater could be a potential water resource if appropriate treatment technologies could be developed. One of the barriers to obtaining high quality water from wastewater arises from the presence of organic micropollutants, which are biologically active at trace levels. Removal of these compounds from wastewater by current physico-chemical technologies is prohibitively expensive. While biological treatment processes...

  6. Biologic

    CERN Document Server

    Kauffman, L H

    2002-01-01

    In this paper we explore the boundary between biology and the study of formal systems (logic). In the end, we arrive at a summary formalism, a chapter in "boundary mathematics" where there are not only containers but also extainers ><, entities open to interaction and distinguishing the space that they are not. The boundary algebra of containers and extainers is to biologic what boolean algebra is to classical logic. We show how this formalism encompasses significant parts of the logic of DNA replication, the Dirac formalism for quantum mechanics, formalisms for protein folding and the basic structure of the Temperley Lieb algebra at the foundations of topological invariants of knots and links.

  7. Systems Biology Investigations of Pseudomonas aeruginosa Evolution in Association with Human Airway Infections

    DEFF Research Database (Denmark)

    Pedersen, Søren Damkiær

    Most knowledge about evolutionary adaptation has been gained from experimental evolution studies, in which organisms have been allowed to evolve under simple, well-defined conditions in the laboratory. While these studies have provided novel insight into the fundamental processes of evolutionary....... aeruginosa DK2 clone lineage during 200,000 generations of evolution in the CF airways from its entrance in the clinic in the 1970’ies until the end of 2010. Genetic analysis showed that the DK2 lineage between 1973 and 2007 accumulated mutations in a near-linear manner with an overall genomic signature of...

  8. Early Precambrian Carbonate and Evapolite Sediments: Constraints on Environmental and Biological Evolution

    Science.gov (United States)

    Grotzinger, John P.

    2002-01-01

    The work accomplished under NASA Grant NAG5-6722 was very successful. Our lab was able to document the occurrence and distribution of evaporite-to-carbonate transitions in several basins during Precambrian time, to help constrain the long-term chemical evolution of seawater.

  9. Pre-Service Science Teachers' Acceptance of Biological Evolution in Turkey

    Science.gov (United States)

    Taskin, Özgür

    2013-01-01

    The present research aims to determine whether or not pre-service science teachers in Turkey are resistant to learning about the theory of evolution (TOE), and to understand the reasons for their acceptance or rejection of this theory. Following an intervention process, essay documents were collected from each participant ("N" = 113) and…

  10. Horizontal Gene Transfer among Bacteria and Its Role in Biological Evolution

    OpenAIRE

    Werner Arber

    2014-01-01

    This is a contribution to the history of scientific advance in the past 70 years concerning the identification of genetic information, its molecular structure, the identification of its functions and the molecular mechanisms of its evolution. Particular attention is thereby given to horizontal gene transfer among microorganisms, as well as to biosafety considerations with regard to beneficial applications of acquired scientific knowledge.

  11. Degrading organic micropollutants: The next challenge in the evolution of biological wastewater treatment processes

    Directory of Open Access Journals (Sweden)

    Naresh eSinghal

    2016-05-01

    Full Text Available Global water scarcity is driving the need for identifying new water source. Wastewater could be a potential water resource if appropriate treatment technologies could be developed. One of the barriers to obtaining high quality water from wastewater arises from the presence of organic micropollutants, which are biologically active at trace levels. Removal of these compounds from wastewater by current physico-chemical technologies is prohibitively expensive. While biological treatment processes are comparatively cheap, current systems are not capable of degrading the wide range of organic micropollutants present in wastewater. As current wastewater treatment processes were developed for treating conventional pollutants present at mg/L levels, degrading the ng/L levels of micropollutants will require a different approach to system design and operation. In this paper we discuss strategies that could be employed to develop biological wastewater treatment systems capable of degrading organic micropollutants.

  12. The development and validation of a scientific attitudes and attitudes toward evolution and creation instrument for Christian college biology students

    Science.gov (United States)

    Tenneson, Michael Gunnar

    2002-01-01

    This study reports on the development of a valid and reliable survey instrument to be used by college biology teachers at Christian colleges to evaluate the scientific attitudes and the attitudes about evolution and attitudes about creationism of their students. Survey questions were largely derived from student responses to open ended interview questions. Content validity was strong as indicated by agreement among content experts through the use of a content validity rating form. Construct validity was examined through the use of principal components analysis of 165 survey responses. Four factors were identified as a result of this analysis: "evolution support," "views of how scientists think/operate," "scientific attitudes," and "hypotheses and theories." These factors were found to be consistent with the three theoretical constructs of scientific attitudes, attitudes about evolution, and attitudes about creationism. Overall instrument reliability, Cronbach's reliability coefficient, alpha, was determined to be 0.64 (N = 165). Readability was found to be at the 7 th grade level. The instrument should be comprehensible by college students.

  13. Enzymes useful for chiral compound synthesis: structural biology, directed evolution, and protein engineering for industrial use.

    Science.gov (United States)

    Kataoka, Michihiko; Miyakawa, Takuya; Shimizu, Sakayu; Tanokura, Masaru

    2016-07-01

    Biocatalysts (enzymes) have many advantages as catalysts for the production of useful compounds as compared to chemical catalysts. The stereoselectivity of the enzymes is one advantage, and thus the stereoselective production of chiral compounds using enzymes is a promising approach. Importantly, industrial application of the enzymes for chiral compound production requires the discovery of a novel useful enzyme or enzyme function; furthermore, improving the enzyme properties through protein engineering and directed evolution approaches is significant. In this review, the significance of several enzymes showing stereoselectivity (quinuclidinone reductase, aminoalcohol dehydrogenase, old yellow enzyme, and threonine aldolase) in chiral compound production is described, and the improvement of these enzymes using protein engineering and directed evolution approaches for further usability is discussed. Currently, enzymes are widely used as catalysts for the production of chiral compounds; however, for further use of enzymes in chiral compound production, improvement of enzymes should be more essential, as well as discovery of novel enzymes and enzyme functions. PMID:27188776

  14. The Evolution of Epigenetics: From Prokaryotes to Humans and Its Biological Consequences

    Science.gov (United States)

    Willbanks, Amber; Leary, Meghan; Greenshields, Molly; Tyminski, Camila; Heerboth, Sarah; Lapinska, Karolina; Haskins, Kathryn; Sarkar, Sibaji

    2016-01-01

    The evolution process includes genetic alterations that started with prokaryotes and now continues in humans. A distinct difference between prokaryotic chromosomes and eukaryotic chromosomes involves histones. As evolution progressed, genetic alterations accumulated and a mechanism for gene selection developed. It was as if nature was experimenting to optimally utilize the gene pool without changing individual gene sequences. This mechanism is called epigenetics, as it is above the genome. Curiously, the mechanism of epigenetic regulation in prokaryotes is strikingly different from that in eukaryotes, mainly higher eukaryotes, like mammals. In fact, epigenetics plays a significant role in the conserved process of embryogenesis and human development. Malfunction of epigenetic regulation results in many types of undesirable effects, including cardiovascular disease, metabolic disorders, autoimmune diseases, and cancer. This review provides a comparative analysis and new insights into these aspects. PMID:27512339

  15. Chromosomal Aberrations Associated with Clonal Evolution and Leukemic Transformation in Fanconi Anemia: Clinical and Biological Implications

    OpenAIRE

    Stefan Meyer; Heidemarie Neitzel; Holger Tönnies

    2012-01-01

    Fanconi anaemia (FA) is an inherited disease with congenital and developmental abnormalities, bone marrow failure, and extreme risk of leukemic transformation. Bone marrow surveillance is an important part of the clinical management of FA and often reveals cytogenetic aberrations. Here, we review bone marrow findings in FA and discuss the clinical and biological implications of chromosomal aberrations associated with leukemic transformation.

  16. Adaptive evolution of a generalist parasitoid: implications for the effectiveness of biological control agents

    OpenAIRE

    Zepeda-Paulo, Francisca A; Ortiz-Martínez, Sebastián A; Figueroa, Christian C.; Lavandero, Blas

    2013-01-01

    The use of alternative hosts imposes divergent selection pressures on parasitoid populations. In response to selective pressures, these populations may follow different evolutionary trajectories. Divergent natural selection could promote local host adaptation in populations, translating into direct benefits for biological control, thereby increasing their effectiveness on the target host. Alternatively, adaptive phenotypic plasticity could be favored over local adaptation in temporal and spat...

  17. Creativity, Biology, and Culture: Further Comments on Evolution of the Creative Mind.

    Science.gov (United States)

    Mumford, Michael D.; Mobley, Michele I.

    1989-01-01

    In reviewing the Lumsden and Findlay model of creative ontogeny and its potential influences on geneculture coevolution, the authors found it consistent with certain aspects of the creative process and suggestive of promising new research avenues. They also concluded that biologically based models, especially concerning cultural innovation, must…

  18. Evolution of the Conceptions of a Secondary Education Biology Teacher: Longitudinal Analysis Using Cognitive Maps

    Science.gov (United States)

    Da-Silva, Consuelo; Mellado, Vicente; Ruiz, Constantino; Porlan, Rafael

    2007-01-01

    We describe a longitudinal study of a secondary education biology teacher at two moments in her career (1993-2002), determining the changes in her conceptions of the nature of science and its teaching and learning, and the factors that favored or hindered such changes. The changes were analyzed using cognitive maps, constructed on the basis of the…

  19. The FISH chromosome painting technique in Biological Dosimetry : Evolution and applicability

    International Nuclear Information System (INIS)

    The capacity of ionising radiation to induce chromosomal aberrations has been used during decades to assess doses in persons accidentally exposed, giving rise to the discipline Biological Dosimetry. the Biological Dosimetry is a complement to the physical methods of dosimetry and in the situations where those are not available represent the only way to asses the doses received. During decades biological dosimetry has used the dicentric score to determine doses, since a good correlation between in vitro and in vivo irradiation results exists and the background yields are low. However, dicentrics yields decrease with time after irradiation. The translocations and insertions represent stable aberrations what means that they do not decrease in further cell divisions. The development at the end of the 80s of the FISH technique (Fluorescence In Situ Hybridization), represented a great step for the applicability of translocations score for biological dosimetry. In this paper, a review of the FISH chromosome painting technique is presented, addressing the facts that have needed to be solve before its routine use in retrospective dosimetry, as well as the aspects that will need further research in the near future. (Author) 54 refs

  20. The Origin and Evolution of Life in Pakistani High School Biology

    Science.gov (United States)

    Asghar, Anila; Wiles, Jason R.; Alters, Brian

    2010-01-01

    This study seeks to inform science education practitioners and researchers in the West about apparent attempts to reconcile science and religion in Pakistan's public school curriculum. We analysed the national high school science curriculum and biology textbooks (English) used in the Government schools in Pakistan, where Islamic faith is the…

  1. Genetic control of chromosome behaviour: Implications in evolution, crop improvement, and human biology

    Science.gov (United States)

    Chromosomes and chromosome pairing are pivotal to all biological sciences. The study of chromosomes helps unravel several aspects of an organism. Although the foundation of genetics occurred with the formulation of the laws of heredity in 1865, long before the discovery of chromosomes, their subsequ...

  2. University Students' Acceptance of Biological Theories--Is Evolution Really Different?

    Science.gov (United States)

    Rutledge, Michael L.; Sadler, Kim Cleary

    2011-01-01

    Understanding students' thinking about scientific theories is fundamental to the development of effective instructional strategies designed to foster scientific literacy. We conducted a study to determine student acceptance of important biological theories and to explore the relationships between their acceptance of scientific theories and their…

  3. Internal Structure of Elementary Particle and Possible Deterministic Mechanism of Biological Evolution

    OpenAIRE

    Melkikh, Alexei V.

    2004-01-01

    The possibility of a complicated internal structure of an elementary particle was analyzed. In this case a particle may represent a quantum computer with many degrees of freedom. It was shown that the probability of new species formation by means of random mutations is negligibly small. Deterministic model of evolution is considered. According to this model DNA nucleotides can change their state under the control of elementary particle internal degrees of freedom.

  4. Recent advances in alveolar biology: Evolution and function of alveolar proteins☆

    OpenAIRE

    Orgeig, Sandra; Hiemstra, Pieter S.; Edwin J A Veldhuizen; Casals, Cristina; Clark, Howard W.; Haczku, Angela; Knudsen, Lars; Possmayer, Fred

    2010-01-01

    This review is focused on the evolution and function of alveolar proteins. The lung faces physical and environmental challenges, due to changing pressures/volumes and foreign pathogens, respectively. The pulmonary surfactant system is integral in protecting the lung from these challenges via two groups of surfactant proteins – the small molecular weight hydrophobic SPs, SP-B and -C, that regulate interfacial adsorption of the lipids, and the large hydrophilic SPs, SP-A and -D, which are surfa...

  5. Directed evolution combined with synthetic biology strategies expedite semi-rational engineering of genes and genomes

    OpenAIRE

    Kang, Zhen; Zhang, Junli; Jin, Peng; Yang, Sen

    2015-01-01

    Owing to our limited understanding of the relationship between sequence and function and the interaction between intracellular pathways and regulatory systems, the rational design of enzyme-coding genes and de novo assembly of a brand-new artificial genome for a desired functionality or phenotype are difficult to achieve. As an alternative approach, directed evolution has been widely used to engineer genomes and enzyme-coding genes. In particular, significant developments toward DNA synthesis...

  6. Why Flavins Are not Competitors of Chlorophyll in the Evolution of Biological Converters of Solar Energy

    OpenAIRE

    Kritsky, Mikhail S.; Taisiya A. Telegina; Vechtomova, Yulia L.; Buglak, Andrey A.

    2012-01-01

    Excited flavin molecules can photocatalyze reactions, leading to the accumulation of free energy in the products, and the data accumulated through biochemical experiments and by modeling prebiological processes suggest that flavins were available in the earliest stages of evolution. Furthermore, model experiments have shown that abiogenic flavin conjugated with a polyamino acid matrix, a pigment that photocatalyzes the phosphorylation of ADP to form ATP, could have been present in the prebiot...

  7. Modeling marrow damage from response data: evolution from radiation biology to benzene toxicity.

    OpenAIRE

    Jones, D T; Morris, M D; Hasan, J S

    1996-01-01

    Consensus principles from radiation biology were used to describe a generic set of nonlinear, first-order differential equations for modeling toxicity-induced compensatory cell kinetics in terms of sublethal injury, repair, direct killing, killing of cells with unrepaired sublethal injury, and repopulation. This cellular model was linked to a probit model of hematopoietic mortality that describes death from infection and/or hemorrhage between 5 and 30 days. Mortality data from 27 experiments ...

  8. Emergence and Evolution of Order in Physical, Chemical, and Biological Systems

    Science.gov (United States)

    Swinney, Harry

    2008-10-01

    Do the Great Red Spot of Jupiter and the spirals in a frog egg have anything in common? The sizes are vastly different and the biology of even a simple frog egg is far more complicated than the physics of a fluid. Yet the patterns formed in such systems, differing widely in scale and in the underlying molecular mechanisms, can in many cases be understood from a common approach.

  9. Synthetic biology for the directed evolution of protein biocatalysts: navigating sequence space intelligently

    OpenAIRE

    Currin, Andrew; Swainston, Neil; Philip J. Day; Kell, Douglas B.

    2014-01-01

    The amino acid sequence of a protein affects both its structure and its function. Thus, the ability to modify the sequence, and hence the structure and activity, of individual proteins in a systematic way, opens up many opportunities, both scientifically and (as we focus on here) for exploitation in biocatalysis. Modern methods of synthetic biology, whereby increasingly large sequences of DNA can be synthesised de novo, allow an unprecedented ability to engineer proteins with novel functions....

  10. MBEToolbox: a Matlab toolbox for sequence data analysis in molecular biology and evolution

    OpenAIRE

    Xia Xuhua; Smith David K; Cai James J; Yuen Kwok-yung

    2005-01-01

    Abstract Background MATLAB is a high-performance language for technical computing, integrating computation, visualization, and programming in an easy-to-use environment. It has been widely used in many areas, such as mathematics and computation, algorithm development, data acquisition, modeling, simulation, and scientific and engineering graphics. However, few functions are freely available in MATLAB to perform the sequence data analyses specifically required for molecular biology and evoluti...

  11. The cosmological model of eternal inflation and the transition from chance to biological evolution in the history of life

    Directory of Open Access Journals (Sweden)

    Koonin Eugene V

    2007-05-01

    Full Text Available Abstract Background Recent developments in cosmology radically change the conception of the universe as well as the very notions of "probable" and "possible". The model of eternal inflation implies that all macroscopic histories permitted by laws of physics are repeated an infinite number of times in the infinite multiverse. In contrast to the traditional cosmological models of a single, finite universe, this worldview provides for the origin of an infinite number of complex systems by chance, even as the probability of complexity emerging in any given region of the multiverse is extremely low. This change in perspective has profound implications for the history of any phenomenon, and life on earth cannot be an exception. Hypothesis Origin of life is a chicken and egg problem: for biological evolution that is governed, primarily, by natural selection, to take off, efficient systems for replication and translation are required, but even barebones cores of these systems appear to be products of extensive selection. The currently favored (partial solution is an RNA world without proteins in which replication is catalyzed by ribozymes and which serves as the cradle for the translation system. However, the RNA world faces its own hard problems as ribozyme-catalyzed RNA replication remains a hypothesis and the selective pressures behind the origin of translation remain mysterious. Eternal inflation offers a viable alternative that is untenable in a finite universe, i.e., that a coupled system of translation and replication emerged by chance, and became the breakthrough stage from which biological evolution, centered around Darwinian selection, took off. A corollary of this hypothesis is that an RNA world, as a diverse population of replicating RNA molecules, might have never existed. In this model, the stage for Darwinian selection is set by anthropic selection of complex systems that rarely but inevitably emerge by chance in the infinite universe

  12. Gene flow and biological conflict systems in the origin and evolution of eukaryotes.

    Science.gov (United States)

    Aravind, L; Anantharaman, Vivek; Zhang, Dapeng; de Souza, Robson F; Iyer, Lakshminarayan M

    2012-01-01

    The endosymbiotic origin of eukaryotes brought together two disparate genomes in the cell. Additionally, eukaryotic natural history has included other endosymbiotic events, phagotrophic consumption of organisms, and intimate interactions with viruses and endoparasites. These phenomena facilitated large-scale lateral gene transfer and biological conflicts. We synthesize information from nearly two decades of genomics to illustrate how the interplay between lateral gene transfer and biological conflicts has impacted the emergence of new adaptations in eukaryotes. Using apicomplexans as example, we illustrate how lateral transfer from animals has contributed to unique parasite-host interfaces comprised of adhesion- and O-linked glycosylation-related domains. Adaptations, emerging due to intense selection for diversity in the molecular participants in organismal and genomic conflicts, being dispersed by lateral transfer, were subsequently exapted for eukaryote-specific innovations. We illustrate this using examples relating to eukaryotic chromatin, RNAi and RNA-processing systems, signaling pathways, apoptosis and immunity. We highlight the major contributions from catalytic domains of bacterial toxin systems to the origin of signaling enzymes (e.g., ADP-ribosylation and small molecule messenger synthesis), mutagenic enzymes for immune receptor diversification and RNA-processing. Similarly, we discuss contributions of bacterial antibiotic/siderophore synthesis systems and intra-genomic and intra-cellular selfish elements (e.g., restriction-modification, mobile elements and lysogenic phages) in the emergence of chromatin remodeling/modifying enzymes and RNA-based regulation. We develop the concept that biological conflict systems served as evolutionary "nurseries" for innovations in the protein world, which were delivered to eukaryotes via lateral gene flow to spur key evolutionary innovations all the way from nucleogenesis to lineage-specific adaptations. PMID:22919680

  13. United theory of biological evolution:Disaster-forced evolution through Supernova, radioactive ash fall-outs, genome instability, and mass extinctions

    Institute of Scientific and Technical Information of China (English)

    Toshikazu Ebisuzaki; Shigenori Maruyama

    2015-01-01

    We present the disaster-forced biological evolution model as a general framework that includes Darwinian “phylogenic gradualism”, Eldredge-Gould’s “punctuated equilibrium”, mass extinctions, and allopatric, parapatric, and sympatric speciation. It describes how reproductive isolation of organisms is established through global disasters due to supernova encounters and local disasters due to radioactive volcanic ash fall-outs by continental alkaline volcanism. Our new evolution model uniquely highlights three major factors of disaster-forced speciation: enhanced mutation rate by higher natural radiation level, smaller population size, and shrunken habitat size (i.e., isolation among the individual pop-ulations). We developed a mathematical model describing speciation of a half-isolated group from a parental group, taking into account the population size (Ne), immigration rate (m), and mutation rate (m). The model gives a quantitative estimate of the speciation, which is consistent with the observations of speciation speed. For example, the speciation takes at least 105 generations, if mutation rate is less than 10?3 per generation per individual. This result is consistent with the previous studies, in which m is assumed to be 10?3e10?5. On the other hand, the speciation is much faster (less than 105 generations) for the case that m is as large as 0.1 in parapatric conditions (mevolution during mass extinction events, such as observed during the Cambrian explosion of biodiversity. A similar rapid speciation (though in a much smaller

  14. The chemical and biological evolution of mature fine tailings in oil sands end-pit lakes

    International Nuclear Information System (INIS)

    This presentation described an innovative bench-scale technique to characterize oil sand tailings and their impact on sediment oxygen demand (SOD) for future end-pit lake model behaviour. SOD is a dominant contributor to oxygen depletion in wetlands. The function and sustainability of a wetland ecosystem depends on the biochemical processes occurring at the sediment-water interface. The biochemical reactions associated with natural sediment can change with the addition of oil sands processed material (OSPM), which can affect SOD and ecosystem viability. It is important to establishing the biotic and abiotic controls of SOD. In order to evaluate the effectiveness of current wetland reclamation designs, it is important to establish the biotic and abiotic controls of SOD. The REDOX chemistry of fresh tailings sediment (MFT) was measured in this laboratory microcosm to determine the chemical and biological influences, and to study the role of developing microbial communities as new mature fine tailings (MFT) age. The study evaluated the changes in the main chemical, physical and biological populations of the MFT in both aerobic and anaerobic microcosms. A combination of microelectrode arrays and DNA profiling at the tailings water interface was used in the study.

  15. Cell-cell channels, viruses, and evolution: via infection, parasitism, and symbiosis toward higher levels of biological complexity.

    Science.gov (United States)

    Baluska, Frantisek

    2009-10-01

    Between prokaryotic cells and eukaryotic cells there is dramatic difference in complexity which represents a problem for the current version of the cell theory, as well as for the current version of evolution theory. In the past few decades, the serial endosymbiotic theory of Lynn Margulis has been confirmed. This results in a radical departure from our understanding of living systems: the eukaryotic cell represents de facto"cells-within-cell." Higher order "cells-within-cell" situations are obvious at the eukaryotic cell level in the form of secondary and tertiary endosymbiosis, or in the male and female gametophytes of higher plants. The next challenge of the current version of the cell theory is represented by the fact that the multicellular fungi and plants are, in fact, supracellular assemblies as their cells are not physically separated from each other. Moreover, there are also examples of alliances and mergings between multicellular organisms. Infection, especially the viral one, but also bacterial and fungal infections, followed by symbiosis, is proposed to act as the major force that drives the biological evolution toward higher complexity. PMID:19845631

  16. The evolution of ERMIONE in mitochondrial biogenesis and lipid homeostasis: An evolutionary view from comparative cell biology.

    Science.gov (United States)

    Wideman, Jeremy G; Muñoz-Gómez, Sergio A

    2016-08-01

    The ER-mitochondria organizing network (ERMIONE) in Saccharomyces cerevisiae is involved in maintaining mitochondrial morphology and lipid homeostasis. ERMES and MICOS are two scaffolding complexes of ERMIONE that contribute to these processes. ERMES is ancient but has been lost in several lineages including animals, plants, and SAR (stramenopiles, alveolates and rhizaria). On the other hand, MICOS is ancient and has remained present in all organisms bearing mitochondrial cristae. The ERMIONE precursor evolved in the α-proteobacterial ancestor of mitochondria which had the central subunit of MICOS, Mic60. The subsequent evolution of ERMIONE and its interactors in eukaryotes reflects the integrative co-evolution of mitochondria and their hosts and the adaptive paths that some lineages have followed in their specialization to certain environments. By approaching the ERMIONE from a perspective of comparative evolutionary cell biology, we hope to shed light on not only its evolutionary history, but also how ERMIONE components may function in organisms other than S. cerevisiae. This article is part of a Special Issue entitled: The cellular lipid landscape edited by Tim P. Levine and Anant K. Menon. PMID:26825688

  17. Evolution as represented through argumentation: A qualitative study on reasoning and argumentation in high school biology teaching practices

    Science.gov (United States)

    Yalcinoglu, Pelin

    This study aimed to explore high school biology teachers' epistemological criteria and their attention to reasoning and argumentation within their instructional practices. This study investigated: (1) what epistemological criteria do high school biology teachers use when justifying the validity of conclusions, (2) what is the frequency of the explicit use of reasoning and argumentation, if any, in high school biology teachers' instructional practices, and to what extend are reasoning and argumentation skills reflected, if at all, in high school biology teachers' modes of assessment. Three different data collection methods were employed in this study; face-to-face interviews, classroom observations, and document collections. Teachers' epistemological criteria were investigated to provide insight about their reasoning structures. This investigation was made possible by having teachers provide an argument about the validity of hypothetical conclusions drawn by the students based on two different scenarios related to evolution. Toulmin's Argument Pattern used to create rubric to analyze high school biology teachers' levels of reasoning through argumentation. Results of the data analysis suggested following findings. First, high school biology teachers participated in this study presented variety of epistemological criteria which were presented as high, moderate and low levels of reasoning through the argumentations. Second, elements of Toulmin's Argument Pattern were visible in the participants teaching practices, however students were not explicitly introduced to a well structured argument in those classrooms. High level of reasoning was not evident in the instructional practices of the observed teachers. High school biology classrooms which were observed in this study do not provide opportunities for students to practice high level of reasoning or improve their argumentation skills. Third, Interview Protocols designed for this study were found useful to identify the

  18. Precambrian sulfur isotopes and a possible role for sulfite in the evolution of biological sulfate reduction

    International Nuclear Information System (INIS)

    This paper examines how and when the biochemical process of dissimilatory sulfate reduction evolved. During sulfate reduction by modern sulfate-reducing bacteria the sulfide produced is enriched in 32S compared to the starting sulfate. This phenomenon is used to interpret the origin of sulfide in both modern and ancient environments. The isotopic compositions of Precambrian sulfide and sulfate minerals suggests that until ca. 2.O Ga before present (B.P.) sulfide was the major S-component in sediments and the hydrosphere and was formed mainly by volcanogenic processes. After ca. 2.O Ga B.P., when free oxygen was maintained in the atmosphere by the biological and abiological sulfide formation. Dissimilatory sulfate reduction then became widespread. (Auth.)

  19. Carbonate Platform Development and Stromatolite Morphogenesis: Constraints on Environmental and Biological Evolution

    Science.gov (United States)

    Grotzinger, John P.

    2003-01-01

    Work has been completed on the digital mapping of a terminal Proterozoic reef complex in Namibia. This complex formed an isolated carbonate platform developed downdip on a carbonate ramp of the Nama Group. The stratigraphic evolution of the platform was digitally reconstructed from an extensive dataset that was compiled by using digital surveying technologies. The platform comprises three accommodation cycles in which each subsequent cycle experienced progressively greater influence of a long-term accommodation increase. Aggradation and progradation during the first cycle resulted in a flat, uniform, sheet-like platform. The coarsening and shallowing-upward sequence representing the first cycle is dominated by columnar stromatolitic thrombolites and massive dolostones with interbedded mudstone-grainstone at the base of the sequence grading into cross-bedded dolostones. The second cycle features aggradation, formation of a distinct margin containing thrombolite mounds and domes, and the development of a bucket geometry. Columnar stromatolitic thrombolites dominate the platform interior. The final stage of platform development shows a deepening trend with initial aggradation and formation of well-bedded, thin deposits in the interior and mound development at the margins. While the interior drowned, the platform margin kept up with rising sea level and a complex pinnacle reef formed containing fused and coalesced thrombolite mounds flanked by bioclastic grainstones (containing Cloudina and Namacalathus fossils) and collapse breccias. A set of isolated large thrombolite mounds flanked by shales indicate the final stage of the carbonate platform. During a progressive increase in accommodation, a flat-topped isolated carbonate platform becomes aerially less extensive by either backstepping or formation of smaller pinnacles or a combination of both. The overall geometric evolution of the studied platform from flat-topped to bucket with elevated margins is recorded in many

  20. Production and packaging of a biological arsenal: evolution of centipede venoms under morphological constraint.

    Science.gov (United States)

    Undheim, Eivind A B; Hamilton, Brett R; Kurniawan, Nyoman D; Bowlay, Greg; Cribb, Bronwen W; Merritt, David J; Fry, Bryan G; King, Glenn F; Venter, Deon J

    2015-03-31

    Venom represents one of the most extreme manifestations of a chemical arms race. Venoms are complex biochemical arsenals, often containing hundreds to thousands of unique protein toxins. Despite their utility for prey capture, venoms are energetically expensive commodities, and consequently it is hypothesized that venom complexity is inversely related to the capacity of a venomous animal to physically subdue prey. Centipedes, one of the oldest yet least-studied venomous lineages, appear to defy this rule. Although scutigeromorph centipedes produce less complex venom than those secreted by scolopendrid centipedes, they appear to rely heavily on venom for prey capture. We show that the venom glands are large and well developed in both scutigerid and scolopendrid species, but that scutigerid forcipules lack the adaptations that allow scolopendrids to inflict physical damage on prey and predators. Moreover, we reveal that scolopendrid venom glands have evolved to accommodate a much larger number of secretory cells and, by using imaging mass spectrometry, we demonstrate that toxin production is heterogeneous across these secretory units. We propose that the differences in venom complexity between centipede orders are largely a result of morphological restrictions of the venom gland, and consequently there is a strong correlation between the morphological and biochemical complexity of this unique venom system. The current data add to the growing body of evidence that toxins are not expressed in a spatially homogenous manner within venom glands, and they suggest that the link between ecology and toxin evolution is more complex than previously thought. PMID:25775536

  1. Evolution of physical and biological characteristics of mesoscale eddy in north-central Red Sea

    KAUST Repository

    Zarokanellos, Nikolaos

    2015-04-01

    Eddies appear to be important to both the physical and biogeochemical dynamics of the Red Sea. Numerical simulations of physical dynamics and remote sensing studies of chlorophyll concentration and sea surface height in the Red Sea indicate their importance to the upper portions of the sea (Raitsos et al., 2013; Yao et al., 2014; Zhan et al., 2014). Despite their apparent importance, process studies of these eddies have been lacking. In March 2013 we began an extended observational study of the north-central Red Sea (NCRS) where anticyclonic eddies have been observed. The study began with a ship-based characterization of the eddy and was followed by a three-month observational time series using an autonomous glider equipped with a CTD, oxygen sensor, and optical sensors for chlorophyll, CDOM and optical backscatter. The ship-based study captured an initial snapshot of an anticyclonic eddy and it\\'s associated biological and bio-optical distributions. Initially, chlorophyll distributions tended to mirror the density distribution, with deeper isopycnals and chlorophyll maximum depth in the anticyclonic eddy center. The anticyclone eddy in March had an along basin diameter of 150 km, penetrated vertically less than 150 m and elevated near surface chlorophyll concentrations appeared along its outer boundary. The shallowing of the pycnocline of the outer boundaries of the anticyclone eddy on March may elevate nutrients into the lower euphotic zone, contributing to phytoplankton productivity and biomass within the eddy. This eddy contains most of the kinetic energy of the region with the maximum velocities up to 30 - 35 cm/s. The eddy appeared to interact with the coastal reefs where exchange particulate and dissolved matter may occur. The autonomous glider provided the spring-to-summer progression of the system with increasing stratification, shallowing of the subsurface chlorophyll maximum, and fluctuations in the position and intensity of the eddy. Our glider effort

  2. Molecules in interstellar clouds. [physical and chemical conditions of star formation and biological evolution

    Science.gov (United States)

    Irvine, W. M.; Hjalmarson, A.; Rydbeck, O. E. H.

    1981-01-01

    The physical conditions and chemical compositions of the gas in interstellar clouds are reviewed in light of the importance of interstellar clouds for star formation and the origin of life. The Orion A region is discussed as an example of a giant molecular cloud where massive stars are being formed, and it is pointed out that conditions in the core of the cloud, with a kinetic temperature of about 75 K and a density of 100,000-1,000,000 molecules/cu cm, may support gas phase ion-molecule chemistry. The Taurus Molecular Clouds are then considered as examples of cold, dark, relatively dense interstellar clouds which may be the birthplaces of solar-type stars and which have been found to contain the heaviest interstellar molecules yet discovered. The molecular species identified in each of these regions are tabulated, including such building blocks of biological monomers as H2O, NH3, H2CO, CO, H2S, CH3CN and H2, and more complex species such as HCOOCH3 and CH3CH2CN.

  3. Life at extreme conditions: neutron scattering studies of biological molecules suggest that evolution selected dynamics

    International Nuclear Information System (INIS)

    The short review concentrates on recent work performed at the neutrons in biology laboratories of the Institut Laue Langevin and Institut de Biologie Structurale in Grenoble. Extremophile organisms have been discovered that require extreme conditions of temperature, pressure or solvent environment for survival. The existence of such organisms poses a significant challenge in understanding the physical chemistry of their proteins, in view of the great sensitivity of protein structure and stability to the aqueous environment and to external conditions in general. Results of neutron scattering measurements on the dynamics of proteins from extremophile organisms, in vitro as well as in vivo, indicated remarkably how adaptation to extreme conditions involves forces and fluctuation amplitudes that have been selected specifically, suggesting that evolutionary macromolecular selection proceeded via dynamics. The experiments were performed on a halophilic protein, and membrane adapted to high salt, a thermophilic enzyme adapted to high temperature and its mesophilic (adapted to 37 degC) homologue; and in vivo for psychrophilic, mesophilic, thermophilic and hyperthermophilic bacteria, adapted respectively to temperatures of 4 degC, 37 degC, 75 degC and 85 degC. Further work demonstrated the existence of a water component of exceptionally low mobility in an extreme halophile from the Dead Sea, which is not present in mesophile bacterial cells. (author)

  4. REDOX CHEMISTRY OF MOLYBDENUM IN NATURAL WATERS AND ITS INVOLVEMENT IN BIOLOGICAL EVOLUTION

    Directory of Open Access Journals (Sweden)

    DeliWang

    2012-12-01

    Full Text Available The transition element molybdenum (Mo possesses diverse valances (+II to +VI, and is involved in forming cofactors in more than 60 enzymes in biology. Redox switching of the element in these enzymes catalyzes a series of metabolic reactions in both prokaryotes and eukaryotes, and the element therefore plays a fundamental role in the global carbon, nitrogen, and sulfur cycling. In the present oxygenated waters, oxidized Mo(VI predominates thermodynamically, whilst reduced Mo species are mainly confined within specific niches including cytoplasm. Only recently has the reduced Mo(V been separated from Mo(VI in sulfidic mats and even in some reducing waters. Given the presence of reduced Mo(V in contemporary anaerobic habitats, it seems that reduced Mo species were present in the ancient reducing ocean (probably under both ferrigenous and sulfidic conditions, prompting the involvement of Mo in enzymes including nitrogenase and nitrate reductase. During the global transition to oxic conditions, reduced Mo species were constrained to specific anaerobic habitats, and efficient uptake systems of oxidized Mo(VI became a selective advantage both for prokaryotic and eukaryotic cells. Some prokaryotes are still able to directly utilize reduced Mo if any exists in ambient environments. In total, this mini-review describes the redox chemistry and biogeochemistry of Mo over the Earth’s history.

  5. Life at extreme conditions: Neutron scattering studies of biological molecules suggest that evolution selected dynamics

    Indian Academy of Sciences (India)

    Joseph (Giuseppe) Zaccai

    2008-10-01

    The short review concentrates on recent work performed at the neutrons in biology laboratories of the Institut Laue Langevin and Institut de Biologie Structurale in Grenoble. Extremophile organisms have been discovered that require extreme conditions of temperature, pressure or solvent environment for survival. The existence of such organisms poses a significant challenge in understanding the physical chemistry of their proteins, in view of the great sensitivity of protein structure and stability to the aqueous environment and to external conditions in general. Results of neutron scattering measurements on the dynamics of proteins from extremophile organisms, in vitro as well as in vivo, indicated remarkably how adaptation to extreme conditions involves forces and fluctuation amplitudes that have been selected specifically, suggesting that evolutionary macromolecular selection proceeded via dynamics. The experiments were performed on a halophilic protein, and membrane adapted to high salt, a thermophilic enzyme adapted to high temperature and its mesophilic (adapted to 37°C) homologue; and in vivo for psychrophilic, mesophilic, thermophilic and hyperthermophilic bacteria, adapted respectively to temperatures of 4°C, 37°C, 75°C and 85°C. Further work demonstrated the existence of a water component of exceptionally low mobility in an extreme halophile from the Dead Sea, which is not present in mesophile bacterial cells.

  6. Teach Softly and Debunk with a Big Stick: A Response to "Evolution, Biology, and Society--A Conversation for the 21st-Century Sociology Classroom"

    Science.gov (United States)

    Hanson, Chad

    2010-01-01

    This article presents the author's response to "Evolution, Biology, and Society: A Conversation for the 21st-Century Sociology Classroom" by Richard Machalek and Michael Martin. Their work serves as a reminder that the discipline is diverse and dynamic. The author appreciates the effort to urge sociology teachers to include genetic concepts in…

  7. Using Fossil Shark Teeth to Illustrate Evolution and Introduce Basic Geologic Concepts in a High School Biology Classroom

    Science.gov (United States)

    Agnew, J. G.; Nunn, J. A.

    2007-12-01

    Shell Foundation sponsors a program at Louisiana State University called Shell Undergraduate Recruitment and Geoscience Education (SURGE). The purpose of SURGE is to help local high school science teachers incorporate geology into their classrooms by providing resources and training. As part of this program, a workshop for high school biology teachers was held at Louisiana State University in Baton Rouge on June 3-5, 2007. We had the teachers do a series of activities on fossil shark teeth to illustrate evolution and introduce basic earth science concepts such as geologic time, superposition, and faunal succession and provided the teachers with lesson plans and materials. As an example, one of our exercises explores the evolution of the megatoothed shark lineage leading to Carcharocles megalodon, the largest predatory shark in history with teeth up to 17 cm long. Megatoothed shark teeth make excellent evolutionary subjects because they have a good fossil record and show continuous transitions in morphology from the Eocene to Pliocene. Our activity follows the learning cycle model. We take advantage of the curiosity of sharks shared by most people, and allow students to explore the variations among different shark teeth and explain the causes of those variations. The objectives of this exercise are to have the students: 1) sort fossil shark teeth into biologically reasonable species; 2) form hypotheses about evolutionary relationships among fossil shark teeth; and 3) describe and interpret evolutionary trends in the fossil Megatoothed lineage. To do the activity, students are divided into groups of 2-3 and given a shuffled set of 72 shark tooth cards with different images of megatoothed shark teeth. They are instructed to group the shark tooth cards into separate species of sharks. After sorting the cards, students are asked to consider the evolutionary relationships among their species and arrange their species chronologically according to the species first

  8. The quantitative study of marked individuals in ecology, evolution and conservation biology: a foreword to the EURING 2003 Conference

    Directory of Open Access Journals (Sweden)

    Senar, J. C.

    2004-06-01

    Full Text Available Few fields in modern ecology have developed as fast as the analysis of marked individuals in the study of wild animal populations (Seber & Schwarz, 2002. This is the topic of EURING Conferences, which from 1986 have been the premier forum for advances in capture-recapture methodology. In this sense, EURING Conferences still maintain the flavour that originally inspired scientific meetings: to disseminate the very last findings, ideas and results on the field. Traditionally, EURING Conferences have been published in the form of Proceedings, which because of their relevant content, become a required reading to anyone interested in the capture-recapture methodology. EURING 2003 was held in Radolfzell (Germany, hosted by the Max Planck Research Centre for Ornithology, and the Proceedings appear as a special issue of Animal Biodiversity and Conservation. The full title of the 2003 meeting was “The quantitative study of marked individuals in ecology, evolution and conservation biology”, which stands for one of the main aims of the meeting: to establish the capture-recapture approach as one of the standard methodologies in studies within these fields. One of the shared views is that capture-recapture methodologies have reached a considerable maturity, but the need still exists to spread their use as a “standard” methodology. The nice review paper by Lebreton et al. (1993 in Trends in Ecology and Evolution is still applicable, in that general ecologists and evolutionary biologists still resist their general use. The same applies to conservation biology, where the analysis of marked individuals may also be a key tool in its development. We hope, with the spread of 2003 Proceedings, to help to fill this gap. The Proceedings follow the same general structure as the Conference. We organised the EURING meeting in 10 technical sessions, covering what we considered as fastest growing areas in the field. We appointed for each session, two chairs, which

  9. Evolution of biological information

    OpenAIRE

    Schneider, Thomas D.

    2000-01-01

    How do genetic systems gain information by evolutionary processes? Answering this question precisely requires a robust, quantitative measure of information. Fortunately, 50 years ago Claude Shannon defined information as a decrease in the uncertainty of a receiver. For molecular systems, uncertainty is closely related to entropy and hence has clear connections to the Second Law of Thermodynamics. These aspects of information theory have allowed the development of a straightforward and practic...

  10. Investigating Greek Biology Teachers' Attitudes towards Evolution Teaching with Respect to Their Pedagogical Content Knowledge: Suggestions for Their Professional Development

    Science.gov (United States)

    Stasinakis, Panagiotis K.; Athanasiou, Kyriacos

    2016-01-01

    Evolution Teaching (ET) among in-service teachers in Greece was examined in an attempt to evaluate their Pedagogical Content Knowledge. Evolution teaching is a problematic issue. For this purpose, we constructed a questionnaire that was distributed to the target population and to which 181 teachers responded. We used quantitative method to…

  11. Evolution in the Caribbean Classroom: A Critical Analysis of the Role of Biology Teachers and Science Standards in Shaping Evolution Instruction in Belize

    Science.gov (United States)

    Nunez, Elvis Enrique; Pringle, Rose M.; Showalter, Kevin Tyler

    2012-01-01

    A survey of the literature on evolution instruction provides evidence that teachers' personal views and understandings can shape instructional approaches and content delivered in science classrooms regardless of established science standards. This study is the first to quantify evolutionary worldviews of in-service teachers in the Caribbean,…

  12. Analyzing Change in Students' Gene-to-Evolution Models in College-Level Introductory Biology

    Science.gov (United States)

    Dauer, Joseph T.; Momsen, Jennifer L.; Speth, Elena Bray; Makohon-Moore, Sasha C.; Long, Tammy M.

    2013-01-01

    Research in contemporary biology has become increasingly complex and organized around understanding biological processes in the context of systems. To better reflect the ways of thinking required for learning about systems, we developed and implemented a pedagogical approach using box-and-arrow models (similar to concept maps) as a foundational…

  13. Teaching Evolution at A-Level: Is "Intelligent Design" a Scientific Theory That Merits Inclusion in the Biology Syllabus?

    Science.gov (United States)

    Freeland, Peter

    2013-01-01

    Charles Darwin supposed that evolution involved a process of gradual change, generated randomly, with the selection and retention over many generations of survival-promoting features. Some theists have never accepted this idea. "Intelligent design" is a relatively recent theory, supposedly based on scientific evidence, which attempts to…

  14. A paradigm for viewing biologic systems as scale-free networks based on energy efficiency: implications for present therapies and the future of evolution.

    Science.gov (United States)

    Yun, Anthony J; Lee, Patrick Y; Doux, John D

    2006-01-01

    A network constitutes an abstract description of the relationships among entities, respectively termed links and nodes. If a power law describes the probability distribution of the number of links per node, the network is said to be scale-free. Scale-free networks feature link clustering around certain hubs based on preferential attachments that emerge due either to merit or legacy. Biologic systems ranging from sub-atomic to ecosystems represent scale-free networks in which energy efficiency forms the basis of preferential attachments. This paradigm engenders a novel scale-free network theory of evolution based on energy efficiency. As environmental flux induces fitness dislocations and compels a new meritocracy, new merit-based hubs emerge, previously merit-based hubs become legacy hubs, and network recalibration occurs to achieve system optimization. To date, Darwinian evolution, characterized by innovation sampling, variation, and selection through filtered termination, has enabled biologic progress through optimization of energy efficiency. However, as humans remodel their environment, increasing the level of unanticipated fitness dislocations and inducing evolutionary stress, the tendency of networks to exhibit inertia and retain legacy hubs engender maladaptations. Many modern diseases may fundamentally derive from these evolutionary displacements. Death itself may constitute a programmed adaptation, terminating individuals who represent legacy hubs and recalibrating the network. As memes replace genes as the basis of innovation, death itself has become a legacy hub. Post-Darwinian evolution may favor indefinite persistence to optimize energy efficiency. We describe strategies to reprogram or decommission legacy hubs that participate in human disease and death. PMID:16580786

  15. Geochemistry of U and Th and its Influence on the Origin and Evolution of the Crust of Earth and the Biological Evolution

    CERN Document Server

    Bao, Xuezhao

    1998-01-01

    We have investigated the migration behaviors of uranium (U) and thorium (Th) in the Earth and other terrestrial planets. Theoretical models of U and Th migration have been proposed. These models suggest that the unique features of the Earth are closely connected with its unique U and Th migration models and distribution patterns. In the Earth, U and Th can combine with oxidative volatile components and water, migrate up to the asthenosphere position to form an enrichment zone (EZ) of U and Th first, and then migrate up further to the crusts through magmatism and metamorphism. We emphasize that the formation of an EZ of U, Th and other heat-producing elements is a prerequisite for the formation of a plate tectonic system. The heat-producing elements, currently mainly U and Th, in the EZ are also the energy sources that drive the formation and evolution of the crust of Earth and create special granitic continental crusts. In other terrestrial planets, including Mercury, Venus, and Mars, an EZ can not be formed ...

  16. Papers presented to the Conference on Large Body Impacts and Terrestrial Evolution: Geological, Climatological, and Biological Implications

    Science.gov (United States)

    1981-01-01

    The effects of large impacts on the environment are discussed and include thermal effects, atmospheric effects, changes in ocean temperatures, and geomagnetic anomalies. Biological factors such as extinction and increases in mutation development were investigated. Geological anomalies studied include stratigraphic gaps, extinction of entire boundary layers from the geological record, and geochemical oddities. Evidence was examined for impact cratering throughout the world.

  17. Evolution in Secondary School Biology Textbooks of the PRC, the USA, and the Latter Stages of the USSR.

    Science.gov (United States)

    Swarts, Frederick A.; And Others

    1994-01-01

    The presentations of evolutionary theory of 13 prominent secondary school biology textbooks (3 Chinese, 8 American, and 2 Soviet) were examined using the methods of content analysis. Pronounced differences in topic emphasis among the 13 textbooks and systematic trends between countries are discussed. (Author/ZWH)

  18. Evolution of natural history information in the 21st century – developing an integrated framework for biological and geographical data

    Science.gov (United States)

    Reusser, Deborah A.; Lee, Henry, II

    2011-01-01

    Threats to marine and estuarine species operate over many spatial scales, from nutrient enrichment at the watershed/estuarine scale to invasive species and climate change at regional and global scales. To help address research questions across these scales, we provide here a standardized framework for a biogeographical information system containing queriable biological data that allows extraction of information on multiple species, across a variety of spatial scales based on species distributions, natural history attributes and habitat requirements. As scientists shift from research on localized impacts on individual species to regional and global scale threats, macroecological approaches of studying multiple species over broad geographical areas are becoming increasingly important. The standardized framework described here for capturing and integrating biological and geographical data is a critical first step towards addressing these macroecological questions and we urge organizations capturing biogeoinformatics data to consider adopting this framework.

  19. On the biological and cultural evolution of shame: Using internet search tools to weight values in many cultures

    OpenAIRE

    Jaffe, Klaus; Florez, Astrid; Gomes, Cristina M.; Rodriguez, Daniel; Achury, Carla

    2014-01-01

    Shame has clear biological roots and its precise form of expression affects social cohesion and cultural characteristics. Here we explore the relative importance between shame and guilt by using Google Translate to produce translation for the words shame, guilt, pain, embarrassment and fear to the 64 languages covered. We also explore the meanings of these concepts among the Yanomami, a horticulturist hunter-gatherer tribe in the Orinoquia. Results show that societies previously described as ...

  20. Has Human Evolution Stopped?

    OpenAIRE

    Templeton, Alan R.

    2010-01-01

    It has been argued that human evolution has stopped because humans now adapt to their environment via cultural evolution and not biological evolution. However, all organisms adapt to their environment, and humans are no exception. Culture defines much of the human environment, so cultural evolution has actually led to adaptive evolution in humans. Examples are given to illustrate the rapid pace of adaptive evolution in response to cultural innovations. These adaptive responses have important ...

  1. The cosmological model of eternal inflation and the transition from chance to biological evolution in the history of life: The possibility of chance emergence of the replication and translation systems, and the protein superfolds

    OpenAIRE

    Koonin, Eugene V

    2007-01-01

    Evolution of life on earth was governed, primarily, by natural selection, with major contribution of other evolutionary processes, such as neutral variation, exaptation, and gene duplication. However, for biological evolution to take off, a certain minimal degree of complexity is required such that a replicating genome encodes means for its own replication with sufficient rate and fidelity. In all existing life forms, this is achieved by dedicated proteins, polymerases (replicases), that are ...

  2. Structural insights into the evolution of a non-biological protein: importance of surface residues in protein fold optimization.

    Directory of Open Access Journals (Sweden)

    Matthew D Smith

    Full Text Available Phylogenetic profiling of amino acid substitution patterns in proteins has led many to conclude that most structural information is carried by interior core residues that are solvent inaccessible. This conclusion is based on the observation that buried residues generally tolerate only conserved sequence changes, while surface residues allow more diverse chemical substitutions. This notion is now changing as it has become apparent that both core and surface residues play important roles in protein folding and stability. Unfortunately, the ability to identify specific mutations that will lead to enhanced stability remains a challenging problem. Here we discuss two mutations that emerged from an in vitro selection experiment designed to improve the folding stability of a non-biological ATP binding protein. These mutations alter two solvent accessible residues, and dramatically enhance the expression, solubility, thermal stability, and ligand binding affinity of the protein. The significance of both mutations was investigated individually and together, and the X-ray crystal structures of the parent sequence and double mutant protein were solved to a resolution limit of 2.8 and 1.65 A, respectively. Comparative structural analysis of the evolved protein to proteins found in nature reveals that our non-biological protein evolved certain structural features shared by many thermophilic proteins. This experimental result suggests that protein fold optimization by in vitro selection offers a viable approach to generating stable variants of many naturally occurring proteins whose structures and functions are otherwise difficult to study.

  3. Lagrangian evolution of DMS during the Southern Ocean gas exchange experiment: The effects of vertical mixing and biological community shift

    Science.gov (United States)

    Yang, M.; Archer, S. D.; Blomquist, B. W.; Ho, D. T.; Lance, V. P.; Torres, R. J.

    2013-12-01

    Concentrations of dimethylsulfide (DMS) and its precursor dimethylsulfoniopropionate (DMSP) are highly variable in time and space. What is driving the variability in DMS(P), and can those variability be explained by physical processes and changes in the biological community? During the Southern Ocean Gas Exchange Experiment (SO GasEx) in the austral fall of 2008, two 3He/SF6 labeled patches were created in the surface water. SF6 and DMS were surveyed continuously in a Lagrangian framework, while direct measurements of air-sea exchange further constrained the gas budgets. Turbulent diffusivity at the base of the mixed layer was estimated from SF6 profiles and used to calculate the vertical fluxes of DMS and nutrients. Increasing mixed layer nutrient concentrations due to mixing were associated with a shift in the phytoplankton community structure, which in turned likely affected the sulfur dynamics on timescales of days. DMS concentration as well as air-sea DMS flux appeared to be decoupled from the DMSP concentration, possibly due to grazing and bacterial DMS production. Contrary to expectations, in an environment with high winds and modest productivity, physical processes (air-sea exchange, photochemistry, vertical mixing) only accounted for a small fraction of DMS loss from the surface water. Among the DMS sinks, inferred biological consumption most likely dominated during SO GasEx.

  4. Biological feedbacks as cause and demise of the Neoproterozoic icehouse: astrobiological prospects for faster evolution and importance of cold conditions.

    Directory of Open Access Journals (Sweden)

    Pekka Janhunen

    Full Text Available Several severe glaciations occurred during the Neoproterozoic eon, and especially near its end in the Cryogenian period (630-850 Ma. While the glacial periods themselves were probably related to the continental positions being appropriate for glaciation, the general coldness of the Neoproterozoic and Cryogenian as a whole lacks specific explanation. The Cryogenian was immediately followed by the Ediacaran biota and Cambrian Metazoan, thus understanding the climate-biosphere interactions around the Cryogenian period is central to understanding the development of complex multicellular life in general. Here we present a feedback mechanism between growth of eukaryotic algal phytoplankton and climate which explains how the Earth system gradually entered the Cryogenian icehouse from the warm Mesoproterozoic greenhouse. The more abrupt termination of the Cryogenian is explained by the increase in gaseous carbon release caused by the more complex planktonic and benthic foodwebs and enhanced by a diversification of metazoan zooplankton and benthic animals. The increased ecosystem complexity caused a decrease in organic carbon burial rate, breaking the algal-climatic feedback loop of the earlier Neoproterozoic eon. Prior to the Neoproterozoic eon, eukaryotic evolution took place in a slow timescale regulated by interior cooling of the Earth and solar brightening. Evolution could have proceeded faster had these geophysical processes been faster. Thus, complex life could theoretically also be found around stars that are more massive than the Sun and have main sequence life shorter than 10 Ga. We also suggest that snow and glaciers are, in a statistical sense, important markers for conditions that may possibly promote the development of complex life on extrasolar planets.

  5. Fundamental Issues Related to the Origin of Melatonin and Melatonin Isomers during Evolution: Relation to Their Biological Functions

    Directory of Open Access Journals (Sweden)

    Dun-Xian Tan

    2014-09-01

    Full Text Available Melatonin and melatonin isomers exist and/or coexist in living organisms including yeasts, bacteria and plants. The levels of melatonin isomers are significantly higher than that of melatonin in some plants and in several fermented products such as in wine and bread. Currently, there are no reports documenting the presence of melatonin isomers in vertebrates. From an evolutionary point of view, it is unlikely that melatonin isomers do not exist in vertebrates. On the other hand, large quantities of the microbial flora exist in the gut of the vertebrates. These microorganisms frequently exchange materials with the host. Melatonin isomers, which are produced by these organisms inevitably enter the host’s system. The origins of melatonin and its isomers can be traced back to photosynthetic bacteria and other primitive unicellular organisms. Since some of these bacteria are believed to be the precursors of mitochondria and chloroplasts these cellular organelles may be the primary sites of melatonin production in animals or in plants, respectively. Phylogenic analysis based on its rate-limiting synthetic enzyme, serotonin N-acetyltransferase (SNAT, indicates its multiple origins during evolution. Therefore, it is likely that melatonin and its isomer are also present in the domain of archaea, which perhaps require these molecules to protect them against hostile environments including extremely high or low temperature. Evidence indicates that the initial and primary function of melatonin and its isomers was to serve as the first-line of defence against oxidative stress and all other functions were acquired during evolution either by the process of adoption or by the extension of its antioxidative capacity.

  6. Nitrogen Substituted Polycyclic Aromatic Hydrocarbon As Capable Interstellar Infrared Spectrum Source Considering Astronomical Chemical Evolution Step To Biological Organic Purine And Adenine

    CERN Document Server

    Ota, Norio

    2016-01-01

    In order to find out capable chemical evolution step from astronomically created organic in interstellar space to biological organic on the earth, infrared spectrum of nitrogen substituted carbon pentagon-hexagon coupled polycyclic aromatic hydrocarbon was analyzed by the density functional theory. Ionization was modeled from neutral to tri-cation. Among one nitrogen and two nitrogen substituted NPAH, we could find good examples showing similar IR behavior with astronomically well observed one as like C8H6N1, C7H5N2, and C7H5N2. We can imagine that such ionized NPAH may be created in interstellar space by attacks of high energy nitrogen and photon. Whereas, in case of three and four nitrogen substituted cases as like C6H4N3 and C5H3N4, there were no candidate showing similar behavior with observed one. Also, IR of typical biological organic with four and five nitrogen substituted one as like purine and adenine resulted no good similarity with observed one. By such theoretical comparison, one capable story of ...

  7. Evolution of specialized spermatheca morphology in ant queens: insight from comparative developmental biology between ants and polistine wasps.

    Science.gov (United States)

    Gotoh, Ayako; Billen, Johan; Hashim, Rosli; Ito, Fuminori

    2009-11-01

    In many ant species, the queens can keep spermatozoa alive in their spermatheca for several years, which goes along with unique morphological characteristics of the queen's spermatheca. The relative spermatheca size in ant queens is prominently larger than that in social wasps. Furthermore, the epithelium lining the spermatheca reservoir of ants consists of columnar cells in the hilar region and squamous cells in the distal region, whereas it is formed by columnar cells only in social wasps. To study the evolution of the unique spermatheca morphology in ant queens, we compared the various processes during spermatheca development between two ponerine ant species of the genus Pachycondyla (=Brachyponera) and three polistine wasp species of the genus Polistes. From histological observations, we can define four developmental events in the ant queens: (1) invagination of the spermatheca primordium, (2) the reservoir wall thickness becomes unequal, (3) the reservoir diameter doubles as the lining epithelial cells become flattened except for the hilar region, and (4) the increase in thickness of the reservoir epithelium is limited to the hilar region which doubles in thickness. In polistine wasps, the second and the third developmental events are absent and the entire epithelium of the spermatheca wall becomes thick in the final step. We therefore conclude that for ant queens the second and third steps are crucial for the enlargement of the spermatheca size, and that the second to the fourth steps are crucial for the specialization of the reservoir wall structure. PMID:19720157

  8. Testing biological hypotheses with embodied robots: adaptations, accidents, and by-products in the evolution of vertebrates

    Directory of Open Access Journals (Sweden)

    Sonia F Roberts

    2014-11-01

    Full Text Available Evolutionary robotics allows biologists to test hypotheses about extinct animals. We modeled some of the first vertebrates, jawless fishes, in order to study the evolution of the trait after which vertebrates are named: vertebrae. We tested the hypothesis that vertebrae are an adaptation for enhanced feeding and fleeing performance. We created a population of autonomous embodied robots, Preyro, in which the number of vertebrae, N, were free to evolve. In addition, two other traits, the span of the caudal fin, b, and the predator detection threshold, ζ, a proxy for the lateral line sensory system, were also allowed to evolve. These three traits were chosen because they evolved early in vertebrates, are all potentially important in feeding and fleeing, and vary in form among species. Preyro took on individual identities in a given generation as defined by the population’s six diploid genotypes, Gi. Each Gi was a 3-tuple, with each element an integer specifying N, b, and, ζ. The small size of the population allowed for genetic drift to operate in concert with random mutation and mating; the presence of these mechanisms of chance provided an opportunity for N to evolve by accident. The presence of three evolvable traits provided an opportunity for direct selection on b and/or ζ to evolve N as a by-product linked trait correlation. In selection trials, different Gi embodied in Preyro attempted to feed at a light source and then flee to avoid a predator robot in pursuit. The fitness of each Gi was calculated from five different types of performance: speed, acceleration, distance to the light, distance to the predator, and the number of predator escapes initiated. In each generation, we measured the selection differential, the selection gradient, the strength of chance, and the indirect correlation selection gradient. These metrics allowed us to understand the relative contributions of the three mechanisms: direct selection, chance, and indirect

  9. On Technology and Evolution

    OpenAIRE

    Radovan, Mario

    2007-01-01

    Evolution creates structures of increasing order and power; in this process the stronger prevail over the weaker and carry the evolution further. Technology is an artificial creation that often threatens life and evolution conceived of as natural phenomena; but technology also supports life and it works together with evolution. However, there are claims that technology will do much more than that, and bring about an entirely new epoch of evolution. Technology will replace the fragile biologic...

  10. Evolution of unusual morphologies in Lentibulariaceae (bladderworts and allies) and Podostemaceae (river-weeds): a pictorial report at the interface of developmental biology and morphological diversification

    Science.gov (United States)

    Rutishauser, Rolf

    2016-01-01

    Background Various groups of flowering plants reveal profound (‘saltational’) changes of their bauplans (architectural rules) as compared with related taxa. These plants are known as morphological misfits that appear as rather large morphological deviations from the norm. Some of them emerged as morphological key innovations (perhaps ‘hopeful monsters’) that gave rise to new evolutionary lines of organisms, based on (major) genetic changes. Scope This pictorial report places emphasis on released bauplans as typical for bladderworts (Utricularia, approx. 230 secies, Lentibulariaceae) and river-weeds (Podostemaceae, three subfamilies, approx. 54 genera, approx. 310 species). Bladderworts (Utricularia) are carnivorous, possessing sucking traps. They live as submerged aquatics (except for their flowers), as humid terrestrials or as epiphytes. Most Podostemaceae are restricted to rocks in tropical river-rapids and waterfalls. They survive as submerged haptophytes in these extreme habitats during the rainy season, emerging with their flowers afterwards. The recent scientific progress in developmental biology and evolutionary history of both Lentibulariaceae and Podostemaceae is summarized. Conclusions Lentibulariaceae and Podostemaceae follow structural rules that are different from but related to those of more typical flowering plants. The roots, stems and leaves – as still distinguishable in related flowering plants – are blurred (‘fuzzy’). However, both families have stable floral bauplans. The developmental switches to unusual vegetative morphologies facilitated rather than prevented the evolution of species diversity in both families. The lack of one-to-one correspondence between structural categories and gene expression may have arisen from the re-use of existing genetic resources in novel contexts. Understanding what developmental patterns are followed in Lentibulariaceae and Podostemaceae is a necessary prerequisite to discover the genetic

  11. Research trends in radiobiology since 40 years. a new approach: the enzymatic repair function of DNA, internal factor in evolution of biological systems under irradiation

    International Nuclear Information System (INIS)

    In the first part of the report, the author attempts to draw an historical scheme of successive research working hypotheses in radiobiology since 1924. Less than a generation ago the effect of radiation exposure were viewed as being direct, immediate, irreparable and unmodifiable. Now it is generally accepted that radiation lesion can also be indirect, delayed, reparable and often modified with appropriate chemical or biochemical treatment. It was however in 1962-1964 that came the decisive breakthrough in radiobiology with the discovery that the cell possesses a natural active self-defense mechanism against whatever stress would affect the integrity of the genetic message contained in the DNA structure itself. The existence of what could be considered as a fourth DNA function i.e. self-repair by enzymatic action under genetic control-brings at least to radiobiology the missing molecular biology basis it needed to get out of its 'phenomenological night' after abandon of the generalization of Lea's theory through lack of experimental evidence. In the second part, which is a prospective one, the author tries to set an enlarged synthesis considering the possible role of DNA repair system not only in cell survival - in presence or absence of dose modifiers or mutagens - but also in the artificial and natural evolution of biological system exposed to sub-lethal doses of radiation. Most recent data from the literature fit well with what must be still considered as a general working hypothesis. Studies dealing with phenotypic and genotypic characters linked with the acquisition of gamma and UV radiation resistance in 'Escherichia coli K12' has been started by the author, in collaboration with O. Tremeau, in order to bring a new experimental contribution in this respect. (author)

  12. THE EVOLUTION OF SOCIAL ORGANIZATION

    OpenAIRE

    Kurtz, Donald

    2011-01-01

    This paper asserts that while culture does change, it does not evolve. In anthropology the explanation for the evolution of the non-biological aspects of the human condition has relied on the paradigm of cultural evolution. This paper argues that non-biological evolution is better explained in terms of the evolution of social organization. It also rejects the materialist bias that dominates the explanations for why and how evolution takes place. Instead it argues that human agents play a larg...

  13. Evolution of Direct Costs in the First Years of Rheumatoid Arthritis: Impact of Early versus Late Biologic Initiation - An Economic Analysis Based on the ESPOIR Cohort.

    OpenAIRE

    Karine Chevreul; Georges Haour; Sandy Lucier; Stephanie Harvard; Marie-Laure Laroche; Xavier Mariette; Alain Saraux; Isabelle Durand-Zaleski; Francis Guillemin; Bruno Fautrel

    2014-01-01

    International audience OBJECTIVES: To estimate annual direct costs of early RA by resource component in an inception cohort, with reference to four distinct treatment strategies: no disease modifying antirheumatic drugs (DMARDs), synthetic DMARDs only, biologic DMARDs in the first year ('first-year biologic', FYB), and biologic DMARDs from the second year after inclusion ('later-year biologic', LYB); to determine predictors of total and non-DMARD related costs. METHODS: The ESPOIR cohort i...

  14. "New" Persuasive Evidence for Evolution.

    Science.gov (United States)

    Max, Edward E.

    1998-01-01

    Discusses some new evidence for evolution that might be useful in persuading students who question the scientific basis for evolution. Draws on findings from the fields of molecular biology and genetics. (DDR)

  15. Investigating Human Evolution Using Digital Imaging & Craniometry

    Science.gov (United States)

    Robertson, John C.

    2007-01-01

    Human evolution is an important and intriguing area of biology. The significance of evolution as a component of biology curricula, at all levels, can not be overstated; the need to make the most of opportunities to effectively educate students in evolution as a central and unifying realm of biology is paramount. Developing engaging laboratory or…

  16. The Evolution and Development of the Universe

    OpenAIRE

    Vidal, Clement; Auffray, Charles; Blin, Alex H.; Chaline, Jean; Crane, Louis; Durt, Thomas; Ekstig, Borje; Fairlamb, Horace; Greben, Jan; Hengeveld, Rob; Heylighen, Francis; Akkerhuis, Gerard Jagers op; Longo, Giuseppe; Lori, Nicolas F.; Noble, Denis

    2009-01-01

    This document is the Special Issue of the First International Conference on the Evolution and Development of the Universe (EDU 2008). Please refer to the preface and introduction for more details on the contributions. Keywords: acceleration, artificial cosmogenesis, artificial life, Big Bang, Big History, biological evolution, biological universe, biology, causality, classical vacuum energy, complex systems, complexity, computational universe, conscious evolution, cosmological artificial sele...

  17. The Biology of Behaviour.

    Science.gov (United States)

    Broom, D. M.

    1981-01-01

    Discusses topics to aid in understanding animal behavior, including the value of the biological approach to psychology, functional systems, optimality and fitness, universality of environmental effects on behavior, and evolution of social behavior. (DS)

  18. Framing Evolution Discussion Intellectually

    Science.gov (United States)

    Oliveira, Alandeom W.; Cook, Kristin; Buck, Gayle A.

    2011-01-01

    This study examines how a first-year biology teacher facilitates a series of whole-class discussions about evolution during the implementation of a problem-based unit. A communicative theoretical perspective is adopted wherein evolution discussions are viewed as social events that the teacher can frame intellectually (i.e., present or organize as…

  19. Learning and Evolution

    OpenAIRE

    Nolfi, S.; Floreano, D.

    1999-01-01

    In the last few years several researchers have resorted to artificial evolution (e.g. genetic algorithms) and learning techniques (e.g. neural networks) for studying the interaction between learning and evolution. These studies have been conducted for two different purposes: (a) looking at the performance advantages obtained by combining these two adaptive techniques; (b) understanding the role of the interaction between learning and evolution in biological organisms. In this paper we describ...

  20. Seevolution: visualizing chromosome evolution

    OpenAIRE

    Esteban-Marcos, Andrés; Darling, Aaron E.; Ragan, Mark A.

    2009-01-01

    Summary: Genome evolution underpins all of biology, yet its principles can be difficult to communicate to the non-specialist. To facilitate broader understanding of genome evolution, we have designed an interactive 3D environment that enables visualization of diverse genome evolution processes. The system can intuitively and interactively animate mutation histories involving genome rearrangement, point mutation, recombination, insertion and deletion. Multiple organisms related by a phylogeny ...

  1. NATURAL TRANSFORMATIONS OF MULTI-LEVEL ORGANISMAL STRUCTURES REPRESENTED AS ORGANISMIC SUPERCATEGORIES: I. Generation of Categorical Limits and Colimits during Biological Development and Evolution

    OpenAIRE

    Baianu, Dr. Ion

    1983-01-01

    A current update of our original 1980 publication entitled "Natural Transformations of Organismic Structures" is here presented, along with the original (1980) article. A unifying approach to the realization of Relational Biology models and Complex System Biology was reported in 1980 for the first time in terms of Natural Transformations between Functors of Organismic Supercategories and their generating categorical diagrams. The representation of organismal structures in terms of Organismic-...

  2. Is genetic evolution predictable?

    Science.gov (United States)

    Stern, David L; Orgogozo, Virginie

    2009-02-01

    Ever since the integration of Mendelian genetics into evolutionary biology in the early 20th century, evolutionary geneticists have for the most part treated genes and mutations as generic entities. However, recent observations indicate that all genes are not equal in the eyes of evolution. Evolutionarily relevant mutations tend to accumulate in hotspot genes and at specific positions within genes. Genetic evolution is constrained by gene function, the structure of genetic networks, and population biology. The genetic basis of evolution may be predictable to some extent, and further understanding of this predictability requires incorporation of the specific functions and characteristics of genes into evolutionary theory. PMID:19197055

  3. Some aspects of the taxonomy, biology, possible evolution and biogeography of nematodes of the spirurine genus Rhabdochona Railliet, 1916 (Rhabdochonidae, Thelazioidea)

    Czech Academy of Sciences Publication Activity Database

    Moravec, František

    2010-01-01

    Roč. 55, č. 2 (2010), s. 144-160. ISSN 1230-2821 R&D Projects: GA MŠk LC522 Institutional research plan: CEZ:AV0Z60220518 Keywords : Rhabdochona * evolution * freshwater fish Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 1.144, year: 2010

  4. Evolution across the Curriculum: Microbiology.

    Science.gov (United States)

    Burmeister, Alita R; Smith, James J

    2016-05-01

    An integrated understanding of microbiology and evolutionary biology is essential for students pursuing careers in microbiology and healthcare fields. In this Perspective, we discuss the usefulness of evolutionary concepts and an overall evolutionary framework for students enrolled in microbiology courses. Further, we propose a set of learning goals for students studying microbial evolution concepts. We then describe some barriers to microbial evolution teaching and learning and encourage the continued incorporation of evidence-based teaching practices into microbiology courses at all levels. Next, we review the current status of microbial evolution assessment tools and describe some education resources available for teaching microbial evolution. Successful microbial evolution education will require that evolution be taught across the undergraduate biology curriculum, with a continued focus on applications and applied careers, while aligning with national biology education reform initiatives. Journal of Microbiology & Biology Education. PMID:27158306

  5. Evolution across the Curriculum: Microbiology

    Science.gov (United States)

    Burmeister, Alita R.; Smith, James J.

    2016-01-01

    An integrated understanding of microbiology and evolutionary biology is essential for students pursuing careers in microbiology and healthcare fields. In this Perspective, we discuss the usefulness of evolutionary concepts and an overall evolutionary framework for students enrolled in microbiology courses. Further, we propose a set of learning goals for students studying microbial evolution concepts. We then describe some barriers to microbial evolution teaching and learning and encourage the continued incorporation of evidence-based teaching practices into microbiology courses at all levels. Next, we review the current status of microbial evolution assessment tools and describe some education resources available for teaching microbial evolution. Successful microbial evolution education will require that evolution be taught across the undergraduate biology curriculum, with a continued focus on applications and applied careers, while aligning with national biology education reform initiatives. Journal of Microbiology & Biology Education PMID:27158306

  6. Embodied Evolution of Learning Ability

    OpenAIRE

    Elfwing, Stefan

    2007-01-01

    Embodied evolution is a methodology for evolutionary robotics that mimics the distributed, asynchronous, and autonomous properties of biological evolution. The evaluation, selection, and reproduction are carried out by cooperation and competition of the robots, without any need for human intervention. An embodied evolution framework is therefore well suited to study the adaptive learning mechanisms for artificial agents that share the same fundamental constraints as biological agents: self-pr...

  7. O comportamento humano em relação a seu ambiente, à luz das teorias biológicas da evolução Human behaviour towards nature from the biological theories of evolution

    Directory of Open Access Journals (Sweden)

    Guilhermo Foladori

    2000-05-01

    Full Text Available De acordo com a teoria neodarwinista em biologia, o fenótipo desempenha papel ínfimo na evolução, que é exclusivamente uma questão genética. Neste artigo, argumentaremos que a teoria a trata de uma visão unilateral da evolução; b existe outra corrente, a fenogenética, que melhor contempla o papel do fenótipo na evolução; e c essa discussão é especialmente importante para se entender o comportamento do ser humano em relação a seu ambienteFollowing the neodarwinist approach in evolutionary biology the phenogenetic plays a marginal role in evolution. Evolution is basically a genetic problem. In this article we will argue that this view is: a unilateral; b there exists another approach, the phenogenetic one that expresses more accurately the role of phenogenetic in evolution; and c this difference is of great importance for the understanding of human behavior towards nature

  8. Evolution and Christian Faith

    Science.gov (United States)

    Roughgarden, J. E.

    2006-12-01

    My recent book, Evolution and Christian Faith explores how evolutionary biology can be portrayed from the religious perspective of Christianity. The principal metaphors for evolutionary biology---differential success at breeding and random mutation, probably originate with the dawn of agriculture and clearly occur in the Bible. The central narrative of evolutionary biology can be presented using Biblical passages, providing an account of evolution that is inherently friendly to a Christian perspective. Still, evolutionary biology is far from complete, and problematic areas pertain to species in which the concept of an individual is poorly defined, and to species in which the expression of gender and sexuality depart from Darwin's sexual-selection templates. The present- day controversy in the US about teaching evolution in the schools provides an opportunity to engage the public about science education.

  9. Quantum mechanism of Biological Search

    OpenAIRE

    Kwon, Younghun

    2006-01-01

    We wish to suggest an algorithm for biological search including DNA search. Our argument supposes that biological search be performed by quantum search.If we assume this, we can naturally answer the following long lasting puzzles such that "Why does DNA use the helix structure?" and "How can the evolution in biological system occur?".

  10. The FISH chromosome painting technique in Biological Dosimetry : Evolution and applicability; La Tecnica de Pintado Cromosomico mediante FISH en Dosimetria Biologica: Evolucion y Aplicabilidad

    Energy Technology Data Exchange (ETDEWEB)

    Oteo, M.; Real, A.

    2005-07-01

    The capacity of ionising radiation to induce chromosomal aberrations has been used during decades to assess doses in persons accidentally exposed, giving rise to the discipline Biological Dosimetry. the Biological Dosimetry is a complement to the physical methods of dosimetry and in the situations where those are not available represent the only way to asses the doses received. During decades biological dosimetry has used the dicentric score to determine doses, since a good correlation between in vitro and in vivo irradiation results exists and the background yields are low. However, dicentrics yields decrease with time after irradiation. The translocations and insertions represent stable aberrations what means that they do not decrease in further cell divisions. The development at the end of the 80s of the FISH technique (Fluorescence In Situ Hybridization), represented a great step for the applicability of translocations score for biological dosimetry. In this paper, a review of the FISH chromosome painting technique is presented, addressing the facts that have needed to be solve before its routine use in retrospective dosimetry, as well as the aspects that will need further research in the near future. (Author) 54 refs.

  11. Quantum biological information theory

    CERN Document Server

    Djordjevic, Ivan B

    2016-01-01

    This book is a self-contained, tutorial-based introduction to quantum information theory and quantum biology. It serves as a single-source reference to the topic for researchers in bioengineering, communications engineering, electrical engineering, applied mathematics, biology, computer science, and physics. The book provides all the essential principles of the quantum biological information theory required to describe the quantum information transfer from DNA to proteins, the sources of genetic noise and genetic errors as well as their effects. Integrates quantum information and quantum biology concepts; Assumes only knowledge of basic concepts of vector algebra at undergraduate level; Provides a thorough introduction to basic concepts of quantum information processing, quantum information theory, and quantum biology; Includes in-depth discussion of the quantum biological channel modelling, quantum biological channel capacity calculation, quantum models of aging, quantum models of evolution, quantum models o...

  12. Darwinian Evolution on a Chip

    OpenAIRE

    Paegel, Brian M.; Joyce, Gerald F.

    2008-01-01

    Author Summary The principles of Darwinian evolution are fundamental to understanding biological organization and have been applied to the development of functional molecules in the test tube. Laboratory evolution is greatly accelerated compared with natural evolution, but it usually requires substantial manipulation by the experimenter. Here we describe a system that relies on computer control and microfluidic chip technology to automate the directed evolution of functional molecules, subjec...

  13. Hydrogen Evolution from Napiergrass by the Combination of Biological Treatment and a Pt-Loaded TiO2-Photocatalytic Reaction

    OpenAIRE

    Masahide Yasuda; Yasuyuki Ishii; Hikaru Tsumagari; Takayuki Tomo; Tsutomu Shiragami

    2011-01-01

    Ethanol and pentose were produced from lignocellulosic napiergrass by the simultaneous saccharification and fermentation process (SSF) using hydrolytic enzyme and S. Cerevisiae. After the ethanol was removed, the pentose solution was subjected to photocatalytic hydrogen evolution with Pt-loaded TiO2 under UV-irradiation. This process converted 100 g of napiergrass into 12.3 g of ethanol and 1.76 g of hydrogen whose total combustion energy of (∆H) was 615 kJ. This was close to the ∆H (639 kJ) ...

  14. A review on biological adaptation: with applications in engineering science

    OpenAIRE

    LiMin Luo; WenJun Zhang

    2014-01-01

    Biological adaptation refers to that organisms change themselves at morphological, physiological, behavioral and molecular level to better survive in a changing environment. It includes phenotype adaptation and molecular adaptation. Biological adaptation is a driving force of evolution. Biological adaptation was described from Darwinian theory of evolution to the theory of molecular evolution in present paper. Adaptive control and adaptive filtering were briefly described also.

  15. Multistage treatment system for raw leachate from sanitary landfill combining biological nitrification-denitrification/solar photo-Fenton/biological processes, at a scale close to industrial--biodegradability enhancement and evolution profile of trace pollutants.

    Science.gov (United States)

    Silva, Tânia F C V; Silva, M Elisabete F; Cunha-Queda, A Cristina; Fonseca, Amélia; Saraiva, Isabel; Sousa, M A; Gonçalves, C; Alpendurada, M F; Boaventura, Rui A R; Vilar, Vítor J P

    2013-10-15

    A multistage treatment system, at a scale close to the industrial, was designed for the treatment of a mature raw landfill leachate, including: a) an activated sludge biological oxidation (ASBO), under aerobic and anoxic conditions; b) a solar photo-Fenton process, enhancing the bio-treated leachate biodegradability, with and without sludge removal after acidification; and c) a final polishing step, with further ASBO. The raw leachate was characterized by a high concentration of humic substances (HS) (1211 mg CHS/L), representing 39% of the dissolved organic carbon (DOC) content, and a high nitrogen content, mainly in the form of ammonium nitrogen (>3.8 g NH4(+)-N/L). In the first biological oxidation step, a 95% removal of total nitrogen and a 39% mineralization in terms of DOC were achieved, remaining only the recalcitrant fraction, mainly attributed to HS (57% of DOC). Under aerobic conditions, the highest nitrification rate obtained was 8.2 mg NH4(+)-N/h/g of volatile suspended solids (VSS), and under anoxic conditions, the maximum denitrification rate obtained was 5.8 mg (NO2(-)-N + NO3(-)-N)/h/g VSS, with a C/N consumption ratio of 2.4 mg CH3OH/mg (NO2(-)-N + NO3(-)-N). The precipitation of humic acids (37% of HS) after acidification of the bio-treated leachate corresponds to a 96% DOC abatement. The amount of UV energy and H2O2 consumption during the photo-Fenton reaction was 30% higher in the experiment without sludge removal and, consequently, the reaction velocity was 30% lower. The phototreatment process led to the depletion of HS >80%, of low-molecular-weight carboxylate anions >70% and other organic micropollutants, thus resulting in a total biodegradability increase of >70%. The second biological oxidation allowed to obtain a final treated leachate in compliance with legal discharge limits regarding water bodies (with the exception of sulfate ions), considering the experiment without sludge. Finally, the high efficiency of the overall treatment

  16. Branching processes in biology

    CERN Document Server

    Kimmel, Marek

    2015-01-01

    This book provides a theoretical background of branching processes and discusses their biological applications. Branching processes are a well-developed and powerful set of tools in the field of applied probability. The range of applications considered includes molecular biology, cellular biology, human evolution and medicine. The branching processes discussed include Galton-Watson, Markov, Bellman-Harris, Multitype, and General Processes. As an aid to understanding specific examples, two introductory chapters, and two glossaries are included that provide background material in mathematics and in biology. The book will be of interest to scientists who work in quantitative modeling of biological systems, particularly probabilists, mathematical biologists, biostatisticians, cell biologists, molecular biologists, and bioinformaticians. The authors are a mathematician and cell biologist who have collaborated for more than a decade in the field of branching processes in biology for this new edition. This second ex...

  17. Evolution and Computing (Dagstuhl Seminar 16011)

    OpenAIRE

    Barton, Nick; Lehre, Per Kristian; Vishnoi, Nisheeth

    2016-01-01

    This report documents the talks and discussions at the Dagstuhl seminar 16011 “Evolution and Computing”. The seminar brought together several research disciplines studying evolution, including population genetics and mathematical biology, theoretical computer science, and evolutionary computation.

  18. Hydrogen Evolution from Napiergrass by the Combination of Biological Treatment and a Pt-Loaded TiO2-Photocatalytic Reaction

    Directory of Open Access Journals (Sweden)

    Masahide Yasuda

    2011-12-01

    Full Text Available Ethanol and pentose were produced from lignocellulosic napiergrass by the simultaneous saccharification and fermentation process (SSF using hydrolytic enzyme and S. Cerevisiae. After the ethanol was removed, the pentose solution was subjected to photocatalytic hydrogen evolution with Pt-loaded TiO2 under UV-irradiation. This process converted 100 g of napiergrass into 12.3 g of ethanol and 1.76 g of hydrogen whose total combustion energy of (∆H was 615 kJ. This was close to the ∆H (639 kJ of the pentose (13.6 g and hexose (27.4 g obtained by the cellulose-saccharification of 100 g of napiergrass.

  19. Enzymological study of the evolution of the technogenic soil submitted to biological recultivation in Bozanta Mare (Maramures county, north-western Romania

    Directory of Open Access Journals (Sweden)

    Cristian Felix BLIDAR

    2009-11-01

    Full Text Available This paper summarizes our research work regarding the dynamics of vegetation growth of miscellaneous species of trees planted and monitored in the particular environment of the tailing pond in Bozanta Mare (Maramures County. The structure of soil bearing high content of heavy metals and cyanides considerably impacts the ecologic conditions of tailing ponds. Aspects related to soil characteristics (such as structure, size of particles, porosity, texture, chemical composition are included. In the framework of our experiment we have planted seedlings belonging to four species of trees: Quercus petraea, Populus tremula, Betula verrucosa, Salix caprea. Our aim was to study the evolution of enzyme activities. Our contribution, based on the outcomes of our research, consists in the formulation of functional correlations spotted between cormophites and enzyme activities, between the species of trees and their environmental underlying conditions, with the overarching goal to optimize the activities undertaken in order to alleviate the tailing ponds inherent to mining activities.

  20. 99mTc(CO)3-Garenoxacin dithiocarbamate synthesis and biological evolution in rats infected with multiresistant Staphylococcus aureus and penicillin-resistant Streptococci

    International Nuclear Information System (INIS)

    99mTc(CO)3-Garenoxacin dithiocarbamate (99mTc(CO)3-GXND) complex was synthesized and biologically characterized in rats artificially infected with multiresistant Staphylococcus aureus (MDRSA) and penicillin-resistant Streptococci (PRSC). The characteristics of the 99mTc(CO)3-GXND complex was assessed in terms of radiochemical stability in saline, serum, in vitro binding with live and heat killed MDRSA and PRSC and biodistribution in rats artificially infected with MDRSA and PRSC. The complex showed maximum radiochemical stability at 30 min and remained more than 90% stable up to 240 min in normal saline after reconstitution. The complex was found stable in serum at 37 deg C up to 16 h. The complex showed in vitro saturated binding with living MDRSA and PRSC. In rats infected with living MDRSA and PRSC the complex showed five higher up take in the infected muscle as compared to the inflamed and normal muscle. No significant difference in uptake of the complex in rats infected with heat killed MDRSA and PRSC was observed. The disappearance of the complex from the blood and appearance in the urinary system confirm the normal biological route of biodistribution and excretion. The high values of the radiochemical stability in normal saline, serum, saturated in vitro binding with living MDRSA and PRSC and significant infected to normal muscles ratios, the 99mTc(CO)3-GXND complex is recommended for the localization of soft tissue infection caused by living MDRSA and PRSC. (author)

  1. Biological Threats

    Science.gov (United States)

    ... Workplace Plans School Emergency Plans Main Content Biological Threats Biological agents are organisms or toxins that can ... for Disease Control and Prevention . Before a Biological Threat Unlike an explosion, a biological attack may or ...

  2. Has Human Evolution Stopped?

    Directory of Open Access Journals (Sweden)

    Alan R. Templeton

    2010-07-01

    Full Text Available It has been argued that human evolution has stopped because humans now adapt to their environment via cultural evolution and not biological evolution. However, all organisms adapt to their environment, and humans are no exception. Culture defines much of the human environment, so cultural evolution has actually led to adaptive evolution in humans. Examples are given to illustrate the rapid pace of adaptive evolution in response to cultural innovations. These adaptive responses have important implications for infectious diseases, Mendelian genetic diseases, and systemic diseases in current human populations. Moreover, evolution proceeds by mechanisms other than natural selection. The recent growth in human population size has greatly increased the reservoir of mutational variants in the human gene pool, thereby enhancing the potential for human evolution. The increase in human population size coupled with our increased capacity to move across the globe has induced a rapid and ongoing evolutionary shift in how genetic variation is distributed within and among local human populations. In particular, genetic differences between human populations are rapidly diminishing and individual heterozygosity is increasing, with beneficial health effects. Finally, even when cultural evolution eliminates selection on a trait, the trait can still evolve due to natural selection on other traits. Our traits are not isolated, independent units, but rather are integrated into a functional whole, so selection on one trait can cause evolution to occur on another trait, sometimes with mildly maladaptive consequences.

  3. Divergent Cumulative Cultural Evolution

    OpenAIRE

    Marriott, Chris; Chebib, Jobran

    2016-01-01

    Divergent cumulative cultural evolution occurs when the cultural evolutionary trajectory diverges from the biological evolutionary trajectory. We consider the conditions under which divergent cumulative cultural evolution can occur. We hypothesize that two conditions are necessary. First that genetic and cultural information are stored separately in the agent. Second cultural information must be transferred horizontally between agents of different generations. We implement a model with these ...

  4. Evolution of proteins.

    Science.gov (United States)

    Dayhoff, M. O.

    1971-01-01

    The amino acid sequences of proteins from living organisms are dealt with. The structure of proteins is first discussed; the variation in this structure from one biological group to another is illustrated by the first halves of the sequences of cytochrome c, and a phylogenetic tree is derived from the cytochrome c data. The relative geological times associated with the events of this tree are discussed. Errors which occur in the duplication of cells during the evolutionary process are examined. Particular attention is given to evolution of mutant proteins, globins, ferredoxin, and transfer ribonucleic acids (tRNA's). Finally, a general outline of biological evolution is presented.

  5. American Institute of Biological Sciences

    Science.gov (United States)

    ... policy goals. News from Nov 20, 2014 Bring Evolution To Your School/Community For Darwin Day 2015. Apply Now for the Gordon Research Conference on Undergraduate Biology Education Research AIBS Education is dedicated to improving ...

  6. Exploring the kinetic and thermodynamic aspects of four-electron electrochemical reactions: electrocatalysis of oxygen evolution by metal oxides and biological systems.

    Science.gov (United States)

    Wang, Vincent C-C

    2016-08-10

    Finding fundamental and general mechanisms for electrochemical reactions, such as the oxygen evolution reaction (OER) from water and reduction of CO2, plays vital roles in developing the desired electrocatalysts for facilitating solar fuel production. Recently, density functional theory (DFT) calculations have shown that there is a universal scaling relation of adsorption energy between key intermediate species, HO(ad) and HOO(ad), on the surface of metal oxides as OER electrocatalysts. In this paper, a kinetic and thermodynamic model for the four-electron electrochemical reaction based on previous OER mechanisms proposed by DFT calculations is developed to further investigate the electrocatalytic properties over a wide range of metal oxides and photosystem II. The OER activity of metal oxides (i.e. electrocatalytic current) calculated from the DFT-calculated equilibrium potentials with kinetic properties, such as the rate constants for interfacial electron transfer and catalytic turnover, can lead to a volcano-shaped trend that agrees with the results observed in experiments. In addition, the kinetic aspects of the impact on the electrocatalysts are evaluated. Finally, comparing the results of metal oxides and photosystem II, and fitting experimental voltammograms give further insights into kinetic and thermodynamic roles. Here, the general guidelines for designing OER electrocatalysts with unified kinetic and thermodynamic properties are presented. PMID:27460039

  7. Language from a biological perspective

    Indian Academy of Sciences (India)

    Mohinish Shukla

    2005-02-01

    The faculty of language is unique to the human species. This implies that there are human-specific biological changes that lie at the basis of human language. However, it is not clear what the nature of such changes are, and how they could be shaped by evolution. In this paper, emphasis is laid on describing language in a Chomskyan manner, as a mental object. This serves as a standpoint to speculate about the biological basis of the emergence and evolution of language.

  8. Integrating Functional, Developmental and Evolutionary Biology into Biology Curricula

    Science.gov (United States)

    Haave, Neil

    2012-01-01

    A complete understanding of life involves how organisms are able to function in their environment and how they arise. Understanding how organisms arise involves both their evolution and development. Thus to completely comprehend living things, biology must study their function, development and evolution. Previous proposals for standardized…

  9. Evolution and Ageing

    OpenAIRE

    de Oliveira, S. Moss; Alves, Domingos; Martins, J. S. Sa

    2000-01-01

    The idea of this review is to connect the different models of evolution to those of biological ageing through Darwin's theory. We start with the Eigen model of quasispecies for microevolution, then introduce the Bak-Sneppen model for macroevolution and, finally, present the Penna model for biological ageing and some of its most important results. We also explore the concept of coevolution using this model.

  10. Spin glasses and biology

    CERN Document Server

    Stein, David

    1992-01-01

    This volume is an introduction to the application of techniques developed for the study of disordered systems to problems which arise in biology. Topics presented include neural networks, adaptation and evolution, maturation of the immune response, and protein dynamics and folding. This book will appeal to students and researchers interested in statistical and condensed matter physics, glasses and spin glasses, and biophysics.

  11. The evolution of airplanes

    Science.gov (United States)

    Bejan, A.; Charles, J. D.; Lorente, S.

    2014-07-01

    The prevailing view is that we cannot witness biological evolution because it occurred on a time scale immensely greater than our lifetime. Here, we show that we can witness evolution in our lifetime by watching the evolution of the flying human-and-machine species: the airplane. We document this evolution, and we also predict it based on a physics principle: the constructal law. We show that the airplanes must obey theoretical allometric rules that unite them with the birds and other animals. For example, the larger airplanes are faster, more efficient as vehicles, and have greater range. The engine mass is proportional to the body size: this scaling is analogous to animal design, where the mass of the motive organs (muscle, heart, lung) is proportional to the body size. Large or small, airplanes exhibit a proportionality between wing span and fuselage length, and between fuel load and body size. The animal-design counterparts of these features are evident. The view that emerges is that the evolution phenomenon is broader than biological evolution. The evolution of technology, river basins, and animal design is one phenomenon, and it belongs in physics.

  12. Epigenetics: Biology's Quantum Mechanics.

    Science.gov (United States)

    Jorgensen, Richard A

    2011-01-01

    The perspective presented here is that modern genetics is at a similar stage of development as were early formulations of quantum mechanics theory in the 1920s and that in 2010 we are at the dawn of a new revolution in genetics that promises to enrich and deepen our understanding of the gene and the genome. The interrelationships and interdependence of two views of the gene - the molecular biological view and the epigenetic view - are explored, and it is argued that the classical molecular biological view is incomplete without incorporation of the epigenetic perspective and that in a sense the molecular biological view has been evolving to include the epigenetic view. Intriguingly, this evolution of the molecular view toward the broader and more inclusive epigenetic view of the gene has an intriguing, if not precise, parallel in the evolution of concepts of atomic physics from Newtonian mechanics to quantum mechanics that are interesting to consider. PMID:22639577

  13. Epigenetics: Biology's Quantum Mechanics

    Directory of Open Access Journals (Sweden)

    Richard A Jorgensen

    2011-04-01

    Full Text Available The perspective presented here is that modern genetics is at a similar stage of development as were early formulations of quantum mechanics theory in the 1920's and that in 2010 we are at the dawn of a new revolution in genetics that promises to enrich and deepen our understanding of the gene and the genome. The interrelationships and interdependence of two views of the gene - the molecular biological view and the epigenetic view - are explored, and it is argued that the classical molecular biological view is incomplete without incorporation of the epigenetic perspective and that in a sense the molecular biological view has been evolving to include the epigenetic view. Intriguingly, this evolution of the molecular view toward the broader and more inclusive epigenetic view of the gene has an intriguing, if not precise, parallel in the evolution of concepts of atomic physics from Newtonian mechanics to quantum mechanics that are interesting to consider.

  14. High School Students' Perceptions of Evolution Instruction: Acceptance and Evolution Learning Experiences

    Science.gov (United States)

    Donnelly, Lisa A.; Kazempour, Mahsa; Amirshokoohi, Aidin

    2009-01-01

    Evolution is an important and sometimes controversial component of high school biology. In this study, we used a mixed methods approach to explore students' evolution acceptance and views of evolution teaching and learning. Students explained their acceptance and rejection of evolution in terms of evidence and conflicts with religion and…

  15. On Multiobjective Evolution Model

    OpenAIRE

    Ahmed, E; Elettreby, M. F.

    2004-01-01

    Self-Organized Criticality (SOC) phenomena could have a significant effect on the dynamics of ecosystems. The Bak-Sneppen (BS) model is a simple and robust model of biological evolution that exhibits punctuated equilibrium behavior. Here we will introduce random version of BS model. Also we generalize the single objective BS model to a multiobjective one.

  16. On Multiobjective Evolution Model

    Science.gov (United States)

    Ahmed, E.; Elettreby, M. F.

    Self-Organized Criticality (SOC) phenomena could have a significant effect on the dynamics of ecosystems. The Bak-Sneppen (BS) model is a simple and robust model of biological evolution that exhibits punctuated equilibrium behavior. Here, we will introduce random version of BS model. We also generalize the single objective BS model to a multiobjective one.

  17. Evolution and the Law

    Science.gov (United States)

    Mayer, William V.

    1973-01-01

    Some court cases and legislative bills have been filed in states to legalize the use of the creationist view (of life forms on earth) in biology textbooks superseding the organic theory of evolution. The law has not yet accepted the religious viewpoint. (PS)

  18. Computational evolution: taking liberties.

    Science.gov (United States)

    Correia, Luís

    2010-09-01

    Evolution has, for a long time, inspired computer scientists to produce computer models mimicking its behavior. Evolutionary algorithm (EA) is one of the areas where this approach has flourished. EAs have been used to model and study evolution, but they have been especially developed for their aptitude as optimization tools for engineering. Developed models are quite simple in comparison with their natural sources of inspiration. However, since EAs run on computers, we have the freedom, especially in optimization models, to test approaches both realistic and outright speculative, from the biological point of view. In this article, we discuss different common evolutionary algorithm models, and then present some alternatives of interest. These include biologically inspired models, such as co-evolution and, in particular, symbiogenetics and outright artificial operators and representations. In each case, the advantages of the modifications to the standard model are identified. The other area of computational evolution, which has allowed us to study basic principles of evolution and ecology dynamics, is the development of artificial life platforms for open-ended evolution of artificial organisms. With these platforms, biologists can test theories by directly manipulating individuals and operators, observing the resulting effects in a realistic way. An overview of the most prominent of such environments is also presented. If instead of artificial platforms we use the real world for evolving artificial life, then we are dealing with evolutionary robotics (ERs). A brief description of this area is presented, analyzing its relations to biology. Finally, we present the conclusions and identify future research avenues in the frontier of computation and biology. Hopefully, this will help to draw the attention of more biologists and computer scientists to the benefits of such interdisciplinary research. PMID:20532997

  19. Culture, Urbanism and Changing Human Biology

    OpenAIRE

    Schell, L M

    2014-01-01

    Anthropologists have long known that human activity driven by culture changes the environment. This is apparent in the archaeological record and through the study of the modern environment. Perhaps the largest change since the paleolithic era is the organization of human populations in cities. New environments can reshape human biology through evolution as shown by the evolution of the hominid lineage. Evolution is not the only process capable of reshaping our biology. Some changes in our hum...

  20. Initiatives in biological research in Indian psychiatry

    OpenAIRE

    Shrivatava, Amresh

    2010-01-01

    Biological psychiatry is an exploratory science for mental health. These biological changes provide some explicit insight into the complex area of ‘brain-mind and behavior’. One major achievement of research in biological field is the finding to explain how biological factors cause changes in behavior. In India, we have a clear history of initiatives in research from a biological perspective, which goes back to 1958. In the last 61 years, this field has seen significant evolution, precision a...

  1. Practices and Perspectives of College Instructors on Addressing Religious Beliefs When Teaching Evolution

    Science.gov (United States)

    Barnes, M. Elizabeth; Brownell, Sara E.

    2016-01-01

    Evolution is a core concept of biology, and yet many college biology students do not accept evolution because of their religious beliefs. However, we do not currently know how instructors perceive their role in helping students accept evolution or how they address the perceived conflict between religion and evolution when they teach evolution.…

  2. Evolution, epigenetics and cooperation

    Indian Academy of Sciences (India)

    Patrick Bateson

    2014-04-01

    Explanations for biological evolution in terms of changes in gene frequencies refer to outcomes rather than process. Integrating epigenetic studies with older evolutionary theories has drawn attention to the ways in which evolution occurs. Adaptation at the level of the gene is givingway to adaptation at the level of the organism and higher-order assemblages of organisms. These ideas impact on the theories of how cooperation might have evolved. Two of the theories, i.e. that cooperating individuals are genetically related or that they cooperate for self-interested reasons, have been accepted for a long time. The idea that adaptation takes place at the level of groups is much more controversial. However, bringing together studies of development with those of evolution is taking away much of the heat in the debate about the evolution of group behaviour.

  3. Darwin and Mendel: Evolution and Genetics

    Science.gov (United States)

    Bizzo, Nelio; El-Hani, Charbel N.

    2009-01-01

    Many studies have shown that students' understanding of evolution is low and some sort of historical approach would be necessary in order to allow students to understand the theory of evolution. It is common to present Mendelian genetics to high school students prior to Biological Evolution, having in mind historical and epistemological…

  4. Insect evolution.

    Science.gov (United States)

    Engel, Michael S

    2015-10-01

    It goes without saying that insects epitomize diversity, and with over a million documented species they stand out as one of the most remarkable lineages in the 3.5-billion-year history of life on earth (Figure 1). This reality is passé to even the layperson and is taken for granted in the same way none of us think much of our breathing as we go about our day, and yet insects are just as vital to our existence. Insects are simultaneously familiar and foreign to us, and while a small fraction are beloved or reviled, most are simply ignored. These inexorable evolutionary overachievers outnumber us all, their segmented body plan is remarkably labile, they combine a capacity for high rates of speciation with low levels of natural extinction, and their history of successes eclipses those of the more familiar ages of dinosaurs and mammals alike. It is their evolution - persisting over vast expanses of geological time and inextricably implicated in the diversification of other lineages - that stands as one of the most expansive subjects in biology. PMID:26439349

  5. The Evolution and Development of the Universe

    CERN Document Server

    Vidal, Clément; Blin, Alex H; Chaline, Jean; Crane, Louis; Durt, Thomas; Ekstig, Borje; Fairlamb, Horace; Greben, Jan; Hengeveld, Rob; Heylighen, Francis; Akkerhuis, Gerard Jagers op; Longo, Giuseppe; Lori, Nicolas F; Noble, Denis; Nottale, Laurent; Salthe, Stanley; Stewart, John; Vaas, Ruediger; Van de Vijver, Gertrudis; van Straalen, Nico M

    2009-01-01

    This document is the Special Issue of the First International Conference on the Evolution and Development (EDU 2008). Please refer to the preface and introduction for more details on the contributions. Keywords: acceleration, artificial cosmogenesis, artificial life, Big Bang, Big History, biological evolution, biological universe, biology, causality, classical vacuum energy, complex systems, complexity, computational universe, conscious evolution, cosmological artificial selection, cosmological natural selection, cosmology, critique, cultural evolution, dark energy, dark matter, development of the universe, development, emergence, evolution of the universe evolution, exobiology, extinction, fine-tuning, fractal space-time, fractal, information, initial conditions, intentional evolution, linear expansion of the universe, log-periodic laws, macroevolution, materialism, meduso-anthropic principle, multiple worlds, natural sciences, Nature, ontology, order, origin of the universe, particle hierarchy, philosophy,...

  6. Cultural Evolution and SETI

    Science.gov (United States)

    Dick, S. J.

    2009-12-01

    The Drake Equation for the number of radio communicative technological civilizations in the Galaxy encompasses three components of cosmic evolution: astronomical, biological and cultural. Of these three, cultural evolution totally dominates in terms of the rapidity of its effects. Yet, SETI scientists do not take cultural evolution into account, perhaps for understandable reasons, since cultural evolution is not well-understood even on Earth and is unpredictable in its outcome. But the one certainty for technical civilizations billions, millions, or even thousands of years older than ours is that they will have undergone cultural evolution. Cultural evolution potentially takes place in many directions, but this paper argues that its central driving force is the maintenance, improvement and perpetuation of knowledge and intelligence, and that to the extent intelligence can be improved, it will be improved. Applying this principle to life in the universe, extraterrestrials will have sought the best way to improve their intelligence. One possibility is that they may have long ago advanced beyond flesh-and-blood to artificial intelligence, constituting a postbiological universe. Although this subject has been broached, it has not been given the attention it is due from its foundation in cultural evolution. Nor has the idea of a postbiological universe been carried to its logical conclusion, including a careful analysis of the implications for SETI. SETI scientists, social scientists, and experts in AI should consider the strengths and weaknesses of this new paradigm.

  7. Evolution of lifespan.

    Science.gov (United States)

    Neill, David

    2014-10-01

    Present-day evolutionary theory, modern synthesis and evo-devo, appear to explain evolution. There remain however several points of contention. These include: biological time, direction, macroevolution verses microevolution, ageing and the extent of internal as opposed to external mediation. A new theoretical model for the control of biological time in vertebrates/bilaterians is introduced. Rather than biological time being controlled solely by a molecular cascade domino effect, it is suggested there is also an intracellular oscillatory clock. This clock (life's timekeeper) is synchronised across all cells in an organism and runs at a constant frequency throughout life. Slower frequencies extend lifespan, increase body/brain size and advance behaviour. They also create a time void which could aid additional evolutionary change. Faster frequencies shorten lifespan, reduce body/brain size and diminish behaviour. They are therefore less likely to mediate evolution in vertebrates/mammals. It is concluded that in vertebrates, especially mammals, there is a direction in evolution towards longer lifespan/advanced behaviour. Lifespan extension could equate with macroevolution and subsequent modifications with microevolution. As life's timekeeper controls the rate of ageing it constitutes a new genetic theory of ageing. Finally, as lifespan extension is internally mediated, this suggests a major role for internal mediation in evolution. PMID:24992233

  8. Biological races in humans.

    Science.gov (United States)

    Templeton, Alan R

    2013-09-01

    Races may exist in humans in a cultural sense, but biological concepts of race are needed to access their reality in a non-species-specific manner and to see if cultural categories correspond to biological categories within humans. Modern biological concepts of race can be implemented objectively with molecular genetic data through hypothesis-testing. Genetic data sets are used to see if biological races exist in humans and in our closest evolutionary relative, the chimpanzee. Using the two most commonly used biological concepts of race, chimpanzees are indeed subdivided into races but humans are not. Adaptive traits, such as skin color, have frequently been used to define races in humans, but such adaptive traits reflect the underlying environmental factor to which they are adaptive and not overall genetic differentiation, and different adaptive traits define discordant groups. There are no objective criteria for choosing one adaptive trait over another to define race. As a consequence, adaptive traits do not define races in humans. Much of the recent scientific literature on human evolution portrays human populations as separate branches on an evolutionary tree. A tree-like structure among humans has been falsified whenever tested, so this practice is scientifically indefensible. It is also socially irresponsible as these pictorial representations of human evolution have more impact on the general public than nuanced phrases in the text of a scientific paper. Humans have much genetic diversity, but the vast majority of this diversity reflects individual uniqueness and not race. PMID:23684745

  9. The Biological Universe

    Science.gov (United States)

    Dick, Steven J.

    2000-03-01

    Introduction; 1. From the physical world to the biological universe: Democritus to Lowell; 2. Plurality of worlds and the decline of anthropocentrism; 3. The solar system: the limits of observation; 4. Solar systems beyond: the limits of theory; 5. Extraterrestrials in literature and the arts: the role of imagination; 6. The UFO controversy: on perception and deception; 7. The origin and evolution of life in the extraterrestrial context; 8. SETI: the Search for Extraterrestrial Intelligence; 9. The convergence of disciplines: birth of a new science; 10. The meaning of life; Summary and conclusion: the biological universe and the limits of science.

  10. Chemical and biological evolution in space

    Science.gov (United States)

    Greenberg, J. M.; Weber, P.; Schutte, W.

    1984-01-01

    The formation of organic molecules in interstellar dust grains and the survival of bacterial spores in a space environment are examined, summarizing the results of experimental investigations and theoretical calculations. The interstellar medium is characterized; the production of organic yellow-stuff residues on the mantles of dust grains in molecular clouds by UV radiation is explained; an IR absorption spectrum toward a Galactic-center source is shown to confirm the presence of such residues; and the mass of such abiotically produced complex organic molecules in the Galaxy is estimated as at least 10 to the 7th solar mass, or 0.1 percent of the mass in the Galaxy. This finding is considered significant for the prebiotic chemistry of the earth, since comets containing large amounts of interstellar dust may have impacted the earth many times during comet showers in the early solar system. UV-irradiation experiments on bacterial spores show that initial exposures to solar UV, not interstellar survival, is the main factor rendering theries of panspermia questionable.

  11. The apoptotic machinery as a biological complex system: analysis of its omics and evolution, identification of candidate genes for fourteen major types of cancer, and experimental validation in CML and neuroblastoma

    Directory of Open Access Journals (Sweden)

    Li Destri Giovanni

    2009-04-01

    Full Text Available Abstract Background Apoptosis is a critical biological phenomenon, executed under the guidance of the Apoptotic Machinery (AM, which allows the physiologic elimination of terminally differentiated, senescent or diseased cells. Because of its relevance to BioMedicine, we have sought to obtain a detailed characterization of AM Omics in Homo sapiens, namely its Genomics and Evolution, Transcriptomics, Proteomics, Interactomics, Oncogenomics, and Pharmacogenomics. Methods This project exploited the methodology commonly used in Computational Biology (i.e., mining of many omics databases of the web as well as the High Throughput biomolecular analytical techniques. Results In Homo sapiens AM is comprised of 342 protein-encoding genes (possessing either anti- or pro-apoptotic activity, or a regulatory function and 110 MIR-encoding genes targeting them: some have a critical role within the system (core AM nodes, others perform tissue-, pathway-, or disease-specific functions (peripheral AM nodes. By overlapping the cancer type-specific AM mutation map in the fourteen most frequent cancers in western societies (breast, colon, kidney, leukaemia, liver, lung, neuroblastoma, ovary, pancreas, prostate, skin, stomach, thyroid, and uterus to their transcriptome, proteome and interactome in the same tumour type, we have identified the most prominent AM molecular alterations within each class. The comparison of the fourteen mutated AM networks (both protein- as MIR-based has allowed us to pinpoint the hubs with a general and critical role in tumour development and, conversely, in cell physiology: in particular, we found that some of these had already been used as targets for pharmacological anticancer therapy. For a better understanding of the relationship between AM molecular alterations and pharmacological induction of apoptosis in cancer, we examined the expression of AM genes in K562 and SH-SY5Y after anticancer treatment. Conclusion We believe that our data

  12. The theory of evolution

    Directory of Open Access Journals (Sweden)

    Oleg Bazaluk

    2015-06-01

    Full Text Available The book The Theory of Evolution: from the Space Vacuum to Neural Ensembles and Moving Forward, an edition of 100 copies, was published in Russian language, in December 2014 in Kiev. Its Russian version is here: http://en.bazaluk.com/journals.html. Introduction, Chapter 10 and Conclusion published in English for the first time. Since 2004 author have been researching in the field of theory of Evolution, Big History. The book was written on the base of analysis of more than 2000 primary sources of this research topic. The volume is 90,000 words (with Reference. The book is for a wide range of professionals, from students to professors and researchers working in the fields of: philosophical anthropology, philosophy, Big History, cosmology, biology, neuroscience and etc. In the book, the author defines the evolution as continuous and nonlinear complication of the structure of matter, the types of interaction and environments; analyzes existing in modern science and philosophy approaches to the research of the process of evolution, degree of development of the factors and causes of evolution. Unifying interdisciplinary researches of evolution in cosmology, biology, neuroscience and philosophy, the author presents his vision of the model of «Evolving Matter», which allows us to consider not only the laws of transition of space vacuum in neural ensembles but also to see our Universe as a complication, heterogeneous organization. Interdisciplinary amount of information on the theory of evolution is systematized and a new method of world perception is proposed in the book.

  13. Spherule Beds 3.47-3.24 Billion Years Old in the Barberton Greenstone Belt, South Africa: A Record of Large Meteorite Impacts and Their Influence on Early Crustal and Biological Evolution

    Science.gov (United States)

    Lowe, Donald R.; Byerly, Gary R.; Kyte, Frank T.; Shukolyukov, Alexander; Asaro, Frank; Krull, Alexander

    2003-01-01

    Four layers, S1-S4, containing sand-sized spherical particles formed as a result of large meteorite impacts, occur in 3.47-3.24 Ga rocks of the Barberton Greenstone Belt, South Africa. Ir levels in S3 and S4 locally equal or exceed chondritic values but in other sections are at or only slightly above background. Most spherules are inferred to have formed by condensation of impact-produced rock vapor clouds, although some may represent ballistically ejected liquid droplets. Extreme Ir abundances and heterogeneity may reflect element fractionation during spherule formation, hydraulic fractionation during deposition, and/or diagenetic and metasomatic processes. Deposition of S1, S2, and S3 was widely influenced by waves and/or currents interpreted to represent impact-generated tsunamis, and S1 and S2 show multiple graded layers indicating the passage of two or more wave trains. These tsunamis may have promoted mixing within a globally stratified ocean, enriching surface waters in nutrients for biological communities. S2 and S3 mark the transition from the 300-million-year-long Onverwacht stage of predominantly basaltic and komatiitic volcanism to the late orogenic stage of greenstone belt evolution, suggesting that regional and possibly global tectonic reorganization resulted from these large impacts. These beds provide the oldest known direct record of terrestrial impacts and an opportunity to explore their influence on early life, crust, ocean, and atmosphere. The apparent presence of impact clusters at 3.26-3.24 Ga and approx. 2.65-2.5 Ga suggests either spikes in impact rates during the Archean or that the entire Archean was characterized by terrestrial impact rates above those currently estimated from the lunar cratering record.

  14. Modeling Protein Evolution

    Science.gov (United States)

    Goldstein, Richard; Pollock, David

    The study of biology is fundamentally different from many other scientific pursuits, such as geology or astrophysics. This difference stems from the ubiquitous questions that arise about function and purpose. These are questions concerning why biological objects operate the way they do: what is the function of a polymerase? What is the role of the immune system? No one, aside from the most dedicated anthropist or interventionist theist, would attempt to determine the purpose of the earth's mantle or the function of a binary star. Among the sciences, it is only biology in which the details of what an object does can be said to be part of the reason for its existence. This is because the process of evolution is capable of improving an object to better carry out a function; that is, it adapts an object within the constraints of mechanics and history (i.e., what has come before). Thus, the ultimate basis of these biological questions is the process of evolution; generally, the function of an enzyme, cell type, organ, system, or trait is the thing that it does that contributes to the fitness (i.e., reproductive success) of the organism of which it is a part or characteristic. Our investigations cannot escape the simple fact that all things in biology (including ourselves) are, ultimately, the result of an evolutionary process.

  15. Learning and the evolution of social systems : an epigenetic perspective

    OpenAIRE

    Eder, Klaus

    1987-01-01

    The theory of epigenetic developments in evolution rests upon two assumptions. First, it refers to developmental processes that decouple biological from genetic evolution. Decoupling evolutionary processes from genetic evolution is even more important for social evolution. Second, it claims that the development of an organism plays a vital role in evolution. It takes into account the specific role individual development plays in evolution. Thus epigenesis refers to definite evolutionary proce...

  16. Noise in biology

    International Nuclear Information System (INIS)

    Noise permeates biology on all levels, from the most basic molecular, sub-cellular processes to the dynamics of tissues, organs, organisms and populations. The functional roles of noise in biological processes can vary greatly. Along with standard, entropy-increasing effects of producing random mutations, diversifying phenotypes in isogenic populations, limiting information capacity of signaling relays, it occasionally plays more surprising constructive roles by accelerating the pace of evolution, providing selective advantage in dynamic environments, enhancing intracellular transport of biomolecules and increasing information capacity of signaling pathways. This short review covers the recent progress in understanding mechanisms and effects of fluctuations in biological systems of different scales and the basic approaches to their mathematical modeling. (review article)

  17. Algorithms, games, and evolution

    OpenAIRE

    Chastain, Erick; Livnat, Adi; Papadimitriou, Christos; Vazirani, Umesh

    2014-01-01

    Theoretical biology was founded on the mathematical tools of statistics and physics. We believe there are productive connections to be made with the younger field of theoretical computer science, which shares with it an interest in complexity and functionality. In this paper, we find that the mathematical description of evolution in the presence of sexual recombination and weak selection is equivalent to a repeated game between genes played according to the multiplicative weight updates algor...

  18. How evolution guides complexity

    OpenAIRE

    LARRY S. YAEGER

    2009-01-01

    Long-standing debates about the role of natural selection in the growth of biological complexity over geological time scales are difficult to resolve from the paleobiological record. Using an evolutionary model—a computational ecosystem subjected to natural selection—we investigate evolutionary trends in an information-theoretic measure of the complexity of the neural dynamics of artificial agents inhabiting the model. Our results suggest that evolution always guides complexity change, just n...

  19. Memory Evolutive Systems

    OpenAIRE

    Ehresmann, Andree; Vanbremeersch, Jean-Paul

    1999-01-01

    Natural autonomous systems, such as biological, neural, social or cultural systems, are open, self-organized systems with a more or less large hierarchy of interacting complexity levels; they are able to memorize their experiences and to adapt to various conditions through a change of behavior. These last fifteen years, the Authors have developed a mathematical model for these systems, based on Category Theory. The aim of the paper is to give an overview of this model, called Memory Evolutive...

  20. Second Symposium on Chemical Evolution and the Origin of Life

    Science.gov (United States)

    Devincenzi, D. L. (Editor); model. (Editor)

    1986-01-01

    Recent findings by NASA Exobiology investigators are reported. Scientific papers are presented in the following areas: cosmic evolution of biogenic compounds, prebiotic evolution (planetary and molecular), early evolution of life (biological and geochemical), evolution of advanced life, solar system exploration, and the Search for Extraterrestrial Intelligence (SETI).

  1. Second Symposium on Chemical Evolution and the Origin of Life

    Energy Technology Data Exchange (ETDEWEB)

    Devincenzi, D.L.; Dufour, P.A.

    1986-05-01

    Recent findings by NASA Exobiology investigators are reported. Scientific papers are presented in the following areas: cosmic evolution of biogenic compounds, prebiotic evolution (planetary and molecular), early evolution of life (biological and geochemical), evolution of advanced life, solar system exploration, and the Search for Extraterrestrial Intelligence (SETI).

  2. Evolution across the Curriculum: Microbiology

    OpenAIRE

    Burmeister, Alita R.; James J. Smith

    2016-01-01

    An integrated understanding of microbiology and evolutionary biology is essential for students pursuing careers in microbiology and healthcare fields. In this Perspective, we discuss the usefulness of evolutionary concepts and an overall evolutionary framework for students enrolled in microbiology courses. Further, we propose a set of learning goals for students studying microbial evolution concepts. We then describe some barriers to microbial evolution teaching and learning and encourage the...

  3. The Pace of Cultural Evolution

    OpenAIRE

    Perreault, Charles

    2012-01-01

    Today, humans inhabit most of the world’s terrestrial habitats. This observation has been explained by the fact that we possess a secondary inheritance mechanism, culture, in addition to a genetic system. Because it is assumed that cultural evolution occurs faster than biological evolution, humans can adapt to new ecosystems more rapidly than other animals. This assumption, however, has never been tested empirically. Here, I compare rates of change in human technologies to rates of change in ...

  4. Cultural commons and cultural evolution

    OpenAIRE

    Giangiacomo Bravo

    2010-01-01

    Culture evolves following a process that is akin to biological evolution, although with some significant differences. At the same time culture has often a collective good value for human groups. This paper studies culture in an evolutionary perspective, with a focus on the implications of group definition for the coexistence of different cultures. A model of cultural evolution is presented where agents interacts in an artificial environment. The belonging to a specific memetic group is a majo...

  5. A Review of Research Instruments Assessing Levels of Student Acceptance of Evolution

    Science.gov (United States)

    Yasri, Pratchayapong

    2014-01-01

    Darwin's theory of evolution by means of natural selection, called evolution for short, is perceived as a unifying theme in biology, forming a major part of all biology syllabuses. It is reported that student acceptance of evolution associates with conceptual understandings of biological contents, nature of science, as well as motivations to…

  6. The pace of cultural evolution.

    Directory of Open Access Journals (Sweden)

    Charles Perreault

    Full Text Available Today, humans inhabit most of the world's terrestrial habitats. This observation has been explained by the fact that we possess a secondary inheritance mechanism, culture, in addition to a genetic system. Because it is assumed that cultural evolution occurs faster than biological evolution, humans can adapt to new ecosystems more rapidly than other animals. This assumption, however, has never been tested empirically. Here, I compare rates of change in human technologies to rates of change in animal morphologies. I find that rates of cultural evolution are inversely correlated with the time interval over which they are measured, which is similar to what is known for biological rates. This correlation explains why the pace of cultural evolution appears faster when measured over recent time periods, where time intervals are often shorter. Controlling for the correlation between rates and time intervals, I show that (1 cultural evolution is faster than biological evolution; (2 this effect holds true even when the generation time of species is controlled for; and (3 culture allows us to evolve over short time scales, which are normally accessible only to short-lived species, while at the same time allowing for us to enjoy the benefits of having a long life history.

  7. Networks of lexical borrowing and lateral gene transfer in language and genome evolution

    OpenAIRE

    List, Johann-Mattis; Nelson-Sathi, Shijulal; Geisler, Hans; Martin, William

    2013-01-01

    Like biological species, languages change over time. As noted by Darwin, there are many parallels between language evolution and biological evolution. Insights into these parallels have also undergone change in the past 150 years. Just like genes, words change over time, and language evolution can be likened to genome evolution accordingly, but what kind of evolution? There are fundamental differences between eukaryotic and prokaryotic evolution. In the former, natural variation entails the g...

  8. Biological trade and markets.

    Science.gov (United States)

    Hammerstein, Peter; Noë, Ronald

    2016-02-01

    Cooperation between organisms can often be understood, like trade between merchants, as a mutually beneficial exchange of services, resources or other 'commodities'. Mutual benefits alone, however, are not sufficient to explain the evolution of trade-based cooperation. First, organisms may reject a particular trade if another partner offers a better deal. Second, while human trade often entails binding contracts, non-human trade requires unwritten 'terms of contract' that 'self-stabilize' trade and prevent cheating even if all traders strive to maximize fitness. Whenever trading partners can be chosen, market-like situations arise in nature that biologists studying cooperation need to account for. The mere possibility of exerting partner choice stabilizes many forms of otherwise cheatable trade, induces competition, facilitates the evolution of specialization and often leads to intricate forms of cooperation. We discuss selected examples to illustrate these general points and review basic conceptual approaches that are important in the theory of biological trade and markets. Comparing these approaches with theory in economics, it turns out that conventional models-often called 'Walrasian' markets-are of limited relevance to biology. In contrast, early approaches to trade and markets, as found in the works of Ricardo and Cournot, contain elements of thought that have inspired useful models in biology. For example, the concept of comparative advantage has biological applications in trade, signalling and ecological competition. We also see convergence between post-Walrasian economics and biological markets. For example, both economists and biologists are studying 'principal-agent' problems with principals offering jobs to agents without being sure that the agents will do a proper job. Finally, we show that mating markets have many peculiarities not shared with conventional economic markets. Ideas from economics are useful for biologists studying cooperation but need

  9. Biological trade and markets

    Science.gov (United States)

    2016-01-01

    Cooperation between organisms can often be understood, like trade between merchants, as a mutually beneficial exchange of services, resources or other ‘commodities’. Mutual benefits alone, however, are not sufficient to explain the evolution of trade-based cooperation. First, organisms may reject a particular trade if another partner offers a better deal. Second, while human trade often entails binding contracts, non-human trade requires unwritten ‘terms of contract’ that ‘self-stabilize’ trade and prevent cheating even if all traders strive to maximize fitness. Whenever trading partners can be chosen, market-like situations arise in nature that biologists studying cooperation need to account for. The mere possibility of exerting partner choice stabilizes many forms of otherwise cheatable trade, induces competition, facilitates the evolution of specialization and often leads to intricate forms of cooperation. We discuss selected examples to illustrate these general points and review basic conceptual approaches that are important in the theory of biological trade and markets. Comparing these approaches with theory in economics, it turns out that conventional models—often called ‘Walrasian’ markets—are of limited relevance to biology. In contrast, early approaches to trade and markets, as found in the works of Ricardo and Cournot, contain elements of thought that have inspired useful models in biology. For example, the concept of comparative advantage has biological applications in trade, signalling and ecological competition. We also see convergence between post-Walrasian economics and biological markets. For example, both economists and biologists are studying ‘principal–agent’ problems with principals offering jobs to agents without being sure that the agents will do a proper job. Finally, we show that mating markets have many peculiarities not shared with conventional economic markets. Ideas from economics are useful for biologists

  10. Biology Notes.

    Science.gov (United States)

    School Science Review, 1982

    1982-01-01

    Presents procedures, exercises, demonstrations, and information on a variety of biology topics including labeling systems, biological indicators of stream pollution, growth of lichens, reproductive capacity of bulbous buttercups, a straw balance to measure transpiration, interaction of fungi, osmosis, and nitrogen fixation and crop production. (DC)

  11. Fourth Symposium on Chemical Evolution and the Origin and Evolution of Life

    Science.gov (United States)

    Wharton, Robert A., Jr. (Editor); Andersen, Dale T. (Editor); Bzik, Sara E. (Editor); Rummel, John D. (Editor)

    1991-01-01

    This symposium was held at the NASA Ames Research Center, Moffett Field, California, July 24-27, 1990. The NASA exobiology investigators reported their recent research findings. Scientific papers were presented in the following areas: cosmic evolution of biogenic compounds, prebiotic evolution (planetary and molecular), early evolution of life (biological and geochemical), evolution of advanced life, solar system exploration, and the Search for Extraterrestrial Intelligence (SETI).

  12. Statistical limitations on molecular evolution.

    Science.gov (United States)

    Perlovsky, Leonid I

    2002-06-01

    Complexity of functions evolving in an evolution process are expected to be limited by the time length of an evolution process among other factors. This paper outlines a general method of deriving function-complexity limitations based on mathematical statistics and independent from details of a biological or genetic mechanism of the evolution of the function. Limitations on the emergence of life are derived, these limitations indicate a possibility of a very fast evolution and are consistent with "RNA world" hypothesis. The discussed method is general and can be used to characterize evolution of more specific biological organism functions and relate functions to genetic structures. The derived general limitations indicate that a co-evolution of multiple functions and species could be a slow process, whereas an evolution of a specific function might proceed very fast, so that no trace of intermediate forms (species) is preserved in fossil records of phenotype or DNA structure; this is consistent with a picture of "punctuated equilibrium". PMID:12023805

  13. Autopoiesis and natural drift: genetic information, reproduction, and evolution revisited.

    Science.gov (United States)

    Etxeberria, Arantza

    2004-01-01

    The contribution of the theory of autopoiesis to the definition of life and biological theory affirms biological autonomy as a central notion of scientific and philosophical inquiry, and opposes other biological approaches, based on the notion of genetic information, that consider reproduction and evolution to be the central aspects of life and living phenomenology. This article reviews the autopoietic criticisms of genetic information, reproduction, and evolution in the light of a biology that can solve the problem of living organization. PMID:15245632

  14. Teaching Molecular Biology with Microcomputers.

    Science.gov (United States)

    Reiss, Rebecca; Jameson, David

    1984-01-01

    Describes a series of computer programs that use simulation and gaming techniques to present the basic principles of the central dogma of molecular genetics, mutation, and the genetic code. A history of discoveries in molecular biology is presented and the evolution of these computer assisted instructional programs is described. (MBR)

  15. Quantum Biology

    Directory of Open Access Journals (Sweden)

    Alessandro Sergi

    2009-06-01

    Full Text Available A critical assessment of the recent developmentsof molecular biology is presented.The thesis that they do not lead to a conceptualunderstanding of life and biological systems is defended.Maturana and Varela's concept of autopoiesis is briefly sketchedand its logical circularity avoided by postulatingthe existence of underlying living processes,entailing amplification from the microscopic to the macroscopic scale,with increasing complexity in the passage from one scale to the other.Following such a line of thought, the currently accepted model of condensed matter, which is based on electrostatics and short-ranged forces,is criticized. It is suggested that the correct interpretationof quantum dispersion forces (van der Waals, hydrogen bonding, and so onas quantum coherence effects hints at the necessity of includinglong-ranged forces (or mechanisms for them incondensed matter theories of biological processes.Some quantum effects in biology are reviewedand quantum mechanics is acknowledged as conceptually important to biology since withoutit most (if not all of the biological structuresand signalling processes would not even exist. Moreover, it is suggested that long-rangequantum coherent dynamics, including electron polarization,may be invoked to explain signal amplificationprocess in biological systems in general.

  16. Stellar evolution

    CERN Document Server

    Meadows, A J

    2013-01-01

    Stellar Evolution, Second Edition covers the significant advances in the understanding of birth, life, and death of stars.This book is divided into nine chapters and begins with a description of the characteristics of stars according to their brightness, distance, size, mass, age, and chemical composition. The next chapters deal with the families, structure, and birth of stars. These topics are followed by discussions of the chemical composition and the evolution of main-sequence stars. A chapter focuses on the unique features of the sun as a star, including its evolution, magnetic fields, act

  17. Power and Biological Potential

    Science.gov (United States)

    Hoehler, T. M.; Som, S. M.; Kempes, C.; Jørgensen, B. B.

    2014-12-01

    Habitability, biomass abundance, growth rates, and rates of evolution are constrained by the availability of biologically accessible energy through time -- power. It is well understood that life requires energy not only to grow, but also to support standing biomass without new growth. Quantifying this "maintenance energy" requirement is critical for understanding the biological potential of low energy systems, including many systems of astrobiological interest, but field- and culture-based estimates differ by as much as three orders of magnitude. Here, we evaluate and compare these estimates to environmental energy supply in two examples: methanogenic metabolism in serpentinizing systems and a hypothetical "thermotrophic" metabolism. In both cases, evaluation of the power budget introduces constraint and resolution beyond that provided by evaluation of Gibbs energy change for metabolic reactions.

  18. Quantum Biology

    CERN Document Server

    Sergi, Alessandro

    2009-01-01

    A critical assessment of the recent developments of molecular biology is presented. The thesis that they do not lead to a conceptual understanding of life and biological systems is defended. Maturana and Varela's concept of autopoiesis is briefly sketched and its logical circularity avoided by postulating the existence of underlying {\\it living processes}, entailing amplification from the microscopic to the macroscopic scale, with increasing complexity in the passage from one scale to the other. Following such a line of thought, the currently accepted model of condensed matter, which is based on electrostatics and short-ranged forces, is criticized. It is suggested that the correct interpretation of quantum dispersion forces (van der Waals, hydrogen bonding, and so on) as quantum coherence effects hints at the necessity of including long-ranged forces (or mechanisms for them) in condensed matter theories of biological processes. Some quantum effects in biology are reviewed and quantum mechanics is acknowledge...

  19. Evolution of Oxygenic Photosynthesis

    Science.gov (United States)

    Fischer, Woodward W.; Hemp, James; Johnson, Jena E.

    2016-06-01

    The origin of oxygenic photosynthesis was the most important metabolic innovation in Earth history. It allowed life to generate energy and reducing power directly from sunlight and water, freeing it from the limited resources of geochemically derived reductants. This greatly increased global primary productivity and restructured ecosystems. The release of O2 as an end product of water oxidation led to the rise of oxygen, which dramatically altered the redox state of Earth's atmosphere and oceans and permanently changed all major biogeochemical cycles. Furthermore, the biological availability of O2 allowed for the evolution of aerobic respiration and novel biosynthetic pathways, facilitating much of the richness we associate with modern biology, including complex multicellularity. Here we critically review and synthesize information from the geological and biological records for the origin and evolution of oxygenic photosynthesis. Data from both of these archives illustrate that this metabolism first appeared in early Paleoproterozoic time and, despite its biogeochemical prominence, is a relatively late invention in the context of our planet's history.

  20. Investigating Evolution with Living Plants.

    Science.gov (United States)

    Schlessman, Mark A.

    1997-01-01

    Describes two investigative labs that use live plants to illustrate important biological principles, include quantitative analysis, and require very little equipment. Each lab is adaptable to a variety of class sizes, course contents, and student backgrounds. Topics include the evolution of flower size in Mimulus and pollination of Brassicas. (DDR)

  1. Cultural evolution as a nonstationary stochastic process

    DEFF Research Database (Denmark)

    Nicholson, Arwen; Sibani, Paolo

    2016-01-01

    We present an individual based model of cultural evolution, where interacting agents are coded by binary strings standing for strategies for action, blueprints for products or attitudes and beliefs. The model is patterned on an established model of biological evolution, the Tangled Nature Model...

  2. Intervening in evolution: Ethics and actions

    OpenAIRE

    Ehrlich, Paul R.

    2001-01-01

    Biologists should help to guide a process of cultural evolution in which society determines how much effort, if any, is ethically required to preserve options in biological evolution. Evolutionists, conservation biologists, and ecologists should be doing more research to determine actions that would best help to avoid foreclosing evolutionary options.

  3. Schumpeter's Evolution

    DEFF Research Database (Denmark)

    Andersen, Esben Sloth

    This draft of a book on Schumpeter is distributed for commenting. It is a stylised intellectual biography that focus on the emergence and extension of the Schumpeterian vision and analysis of economic and social evolution. The draft provides novel interpretations of Schumpeter's six major books. He...... reworking of his basic theory of economic evolution in Development from 1934, and this reworking was continued in Cycles from 1939. Here Schumpeter also tried to handle the statistical and historical evidence on the waveform evolution of the capitalist economy. Capitalism from 1942 modified the model of...... economic evolution and added evolutionary contributions to other social sciences. History, which was published by his widow, was based on his evolutionary theory of the history of economic analysis. This sequential analysis of Schumpeter's six books demonstrates the progress he within his research...

  4. Microarray Data Analysis of Gene Expression Evolution

    OpenAIRE

    Honghuang Lin

    2009-01-01

    Microarrays are becoming a widely used tool to study gene expression evolution. A recent paper by Wang and Rekaya describes a comprehensive study of gene expression evolution by microarray.1 The work provides a perspective to study gene expression evolution in terms of functional enrichment and promoter conservation. It was found that gene expression patterns are highly conserved in some biological processes, but the correlation between promoter and gene expression is insignificant. This scop...

  5. Directed evolution: selection of the host organism

    OpenAIRE

    Azadeh Pourmir; Johannes, Tyler W.

    2012-01-01

    Directed evolution has become a well-established tool for improving proteins and biological systems. A critical aspect of directed evolution is the selection of a suitable host organism for achieving functional expression of the target gene. To date, most directed evolution studies have used either Escherichia coli or Saccharomyces cerevisiae as a host; however, other bacterial and yeast species, as well as mammalian and insect cell lines, have also been successfully used. Recent advances in ...

  6. Bacterial Evolution and Bak-Sneppen Model

    OpenAIRE

    Bose, Indrani; Chaudhuri, Indranath

    2002-01-01

    Recently, Lenski et al [Elena,Lenski,Travisano] have carried out several experiments on bacterial evolution. Their findings support the theory of punctuated equilibrium in biological evolution. They have further quantified the relative contributions of adaptation, chance and history to bacterial evolution. In this paper, we show that a modified $M$-trait Bak-Sneppen model can explain many of the experimental results in a qualitative manner.

  7. Six Classroom Exercises to Teach Natural Selection to Undergraduate Biology Students

    OpenAIRE

    Kalinowski, Steven T.; Leonard, Mary J.; Andrews, Tessa M.; Litt, Andrea R.

    2013-01-01

    Students in introductory biology courses frequently have misconceptions regarding natural selection. In this paper, we describe six activities that biology instructors can use to teach undergraduate students in introductory biology courses how natural selection causes evolution. These activities begin with a lesson introducing students to natural selection and also include discussions on sexual selection, molecular evolution, evolution of complex traits, and the evolution of behavior. The set...

  8. Biologically inspired intelligent robots

    Science.gov (United States)

    Bar-Cohen, Yoseph; Breazeal, Cynthia

    2003-07-01

    Humans throughout history have always sought to mimic the appearance, mobility, functionality, intelligent operation, and thinking process of biological creatures. This field of biologically inspired technology, having the moniker biomimetics, has evolved from making static copies of human and animals in the form of statues to the emergence of robots that operate with realistic behavior. Imagine a person walking towards you where suddenly you notice something weird about him--he is not real but rather he is a robot. Your reaction would probably be "I can't believe it but this robot looks very real" just as you would react to an artificial flower that is a good imitation. You may even proceed and touch the robot to check if your assessment is correct but, as oppose to the flower case, the robot may be programmed to respond physical and verbally. This science fiction scenario could become a reality as the current trend continues in developing biologically inspired technologies. Technology evolution led to such fields as artificial muscles, artificial intelligence, and artificial vision as well as biomimetic capabilities in materials science, mechanics, electronics, computing science, information technology and many others. This paper will review the state of the art and challenges to biologically-inspired technologies and the role that EAP is expected to play as the technology evolves.

  9. Evolution and the End of a World

    Science.gov (United States)

    Long, David Edward

    2010-01-01

    This dissertation examines college student understanding and attitudes toward biological evolution. In ethnographic work, I followed a cohort of 31 students through their required introductory biology class. In interviews, students discuss their life history with the concept--in school, at home, at church, and in their communities. For some…

  10. Biological Oceanography

    Science.gov (United States)

    Abbott, M. R.

    1984-01-01

    Within the framework of global biogeochemical cycles and ocean productivity, there are two areas that will be of particular interest to biological oceanography in the 1990s. The first is the mapping in space time of the biomass and productivity of phytoplankton in the world ocean. The second area is the coupling of biological and physical processes as it affects the distribution and growth rate of phytoplankton biomass. Certainly other areas will be of interest to biological oceanographers, but these two areas are amenable to observations from satellites. Temporal and spatial variability is a regular feature of marine ecosystems. The temporal and spatial variability of phytoplankton biomass and productivity which is ubiquitous at all time and space scales in the ocean must be characterized. Remote sensing from satellites addresses these problems with global observations of mesocale (2 to 20 days, 10 to 200 km) features over a long period of time.

  11. Biological preconcentrator

    Science.gov (United States)

    Manginell, Ronald P.; Bunker, Bruce C.; Huber, Dale L.

    2008-09-09

    A biological preconcentrator comprises a stimulus-responsive active film on a stimulus-producing microfabricated platform. The active film can comprise a thermally switchable polymer film that can be used to selectively absorb and desorb proteins from a protein mixture. The biological microfabricated platform can comprise a thin membrane suspended on a substrate with an integral resistive heater and/or thermoelectric cooler for thermal switching of the active polymer film disposed on the membrane. The active polymer film can comprise hydrogel-like polymers, such as poly(ethylene oxide) or poly(n-isopropylacrylamide), that are tethered to the membrane. The biological preconcentrator can be fabricated with semiconductor materials and technologies.

  12. Research trends in radiobiology since 40 years. a new approach: the enzymatic repair function of DNA, internal factor in evolution of biological systems under irradiation; Etude des tendances des recherches en radiologie depuis 40 ans. Une nouvelle voie de recherche: la fonction de reparation enzymatique de l'ADN, facteur interne d'evolution des systemes biologiques sous rayonnement

    Energy Technology Data Exchange (ETDEWEB)

    Mouton, R. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1968-07-01

    In the first part of the report, the author attempts to draw an historical scheme of successive research working hypotheses in radiobiology since 1924. Less than a generation ago the effect of radiation exposure were viewed as being direct, immediate, irreparable and unmodifiable. Now it is generally accepted that radiation lesion can also be indirect, delayed, reparable and often modified with appropriate chemical or biochemical treatment. It was however in 1962-1964 that came the decisive breakthrough in radiobiology with the discovery that the cell possesses a natural active self-defense mechanism against whatever stress would affect the integrity of the genetic message contained in the DNA structure itself. The existence of what could be considered as a fourth DNA function i.e. self-repair by enzymatic action under genetic control-brings at least to radiobiology the missing molecular biology basis it needed to get out of its 'phenomenological night' after abandon of the generalization of Lea's theory through lack of experimental evidence. In the second part, which is a prospective one, the author tries to set an enlarged synthesis considering the possible role of DNA repair system not only in cell survival - in presence or absence of dose modifiers or mutagens - but also in the artificial and natural evolution of biological system exposed to sub-lethal doses of radiation. Most recent data from the literature fit well with what must be still considered as a general working hypothesis. Studies dealing with phenotypic and genotypic characters linked with the acquisition of gamma and UV radiation resistance in 'Escherichia coli K12' has been started by the author, in collaboration with O. Tremeau, in order to bring a new experimental contribution in this respect. (author) [French] Dans la premiere partie, l'auteur tente de retracer l'historique des hypotheses successives qui ont jalonne les avances de la radiobiologie depuis 1924

  13. Words as alleles: connecting language evolution with Bayesian learners to models of genetic drift

    OpenAIRE

    Reali, Florencia; Griffiths, Thomas L.

    2009-01-01

    Scientists studying how languages change over time often make an analogy between biological and cultural evolution, with words or grammars behaving like traits subject to natural selection. Recent work has exploited this analogy by using models of biological evolution to explain the properties of languages and other cultural artefacts. However, the mechanisms of biological and cultural evolution are very different: biological traits are passed between generations by genes, while languages and...

  14. Marine Biology

    Science.gov (United States)

    Dewees, Christopher M.; Hooper, Jon K.

    1976-01-01

    A variety of informational material for a course in marine biology or oceanology at the secondary level is presented. Among the topics discussed are: food webs and pyramids, planktonic blooms, marine life, plankton nets, food chains, phytoplankton, zooplankton, larval plankton and filter feeders. (BT)

  15. Biology Notes.

    Science.gov (United States)

    School Science Review, 1983

    1983-01-01

    Describes laboratory procedures, demonstrations, and classroom activities/materials, including water relation exercise on auxin-treated artichoke tuber tissue; aerobic respiration in yeast; an improved potometer; use of mobiles in biological classification, and experiments on powdery mildews and banana polyphenol oxidase. Includes reading lists…

  16. Why Am I Learning Evolution? Pointers towards Enacted Scientific Literacy

    Science.gov (United States)

    Olander, Clas

    2013-01-01

    This paper explores affordances in teaching evolution, especially those in which evolution is made relevant to and argued for in a grade 9 biology classroom, thus giving potential answers to the pupils' legitimate question,"'why am I learning evolution?" The aim of the paper is methodological in the sense that it explores…

  17. Practices and Perspectives of College Instructors on Addressing Religious Beliefs When Teaching Evolution.

    Science.gov (United States)

    Barnes, M Elizabeth; Brownell, Sara E

    2016-01-01

    Evolution is a core concept of biology, and yet many college biology students do not accept evolution because of their religious beliefs. However, we do not currently know how instructors perceive their role in helping students accept evolution or how they address the perceived conflict between religion and evolution when they teach evolution. This study explores instructor practices and beliefs related to mitigating students' perceived conflict between religion and evolution. Interviews with 32 instructors revealed that many instructors do not believe it is their goal to help students accept evolution and that most instructors do not address the perceived conflict between religion and evolution. Instructors cited many barriers to discussing religion in the context of evolution in their classes, most notably the instructors' own personal beliefs that religion and evolution may be incompatible. These data are exploratory and are intended to stimulate a series of questions about how we as college biology instructors teach evolution. PMID:27193289

  18. Practices and Perspectives of College Instructors on Addressing Religious Beliefs When Teaching Evolution

    Science.gov (United States)

    Barnes, M. Elizabeth; Brownell, Sara E.

    2016-01-01

    Evolution is a core concept of biology, and yet many college biology students do not accept evolution because of their religious beliefs. However, we do not currently know how instructors perceive their role in helping students accept evolution or how they address the perceived conflict between religion and evolution when they teach evolution. This study explores instructor practices and beliefs related to mitigating students’ perceived conflict between religion and evolution. Interviews with 32 instructors revealed that many instructors do not believe it is their goal to help students accept evolution and that most instructors do not address the perceived conflict between religion and evolution. Instructors cited many barriers to discussing religion in the context of evolution in their classes, most notably the instructors’ own personal beliefs that religion and evolution may be incompatible. These data are exploratory and are intended to stimulate a series of questions about how we as college biology instructors teach evolution. PMID:27193289

  19. Continuous "in vitro" Evolution of a Ribozyme Ligase: A Model Experiment for the Evolution of a Biomolecule

    Science.gov (United States)

    Ledbetter, Michael P.; Hwang, Tony W.; Stovall, Gwendolyn M.; Ellington, Andrew D.

    2013-01-01

    Evolution is a defining criterion of life and is central to understanding biological systems. However, the timescale of evolutionary shifts in phenotype limits most classroom evolution experiments to simple probability simulations. "In vitro" directed evolution (IVDE) frequently serves as a model system for the study of Darwinian…

  20. Representing Evolution

    DEFF Research Database (Denmark)

    Hedin, Gry

    2012-01-01

    article discusses Willumsen's etching in the context of evolutionary theory, arguing that Willumsen is a rare example of an artist who not only let the theory of evolution fuel his artistic imagination, but also concerned himself with a core issue of the theory, namely to what extent it could be applied...

  1. Cepheid evolution

    International Nuclear Information System (INIS)

    A review of the phases of stellar evolution relevant to Cepheid variables of both Types I and II is presented. Type I Cepheids arise as a result of normal post-main sequence evolutionary behavior of many stars in the intermediate to massive range of stellar masses. In contrast, Type II Cepheids generally originate from low-mass stars of low metalicity which are undergoing post core helium-burning evolution. Despite great progress in the past two decades, uncertainties still remain in such areas as how to best model convective overshoot, semiconvection, stellar atmospheres, rotation, and binary evolution as well as uncertainties in important physical parameters such as the nuclear reaction rates, opacity, and mass loss rates. The potential effect of these uncertainties on stellar evolution models is discussed. Finally, comparisons between theoretical predictions and observations of Cepheid variables are presented for a number of cases. The results of these comparisons show both areas of agreement and disagreement with the latter result providing incentive for further research

  2. Cultural evolution: implications for understanding the human language faculty and its evolution.

    Science.gov (United States)

    Smith, Kenny; Kirby, Simon

    2008-11-12

    Human language is unique among the communication systems of the natural world: it is socially learned and, as a consequence of its recursively compositional structure, offers open-ended communicative potential. The structure of this communication system can be explained as a consequence of the evolution of the human biological capacity for language or the cultural evolution of language itself. We argue, supported by a formal model, that an explanatory account that involves some role for cultural evolution has profound implications for our understanding of the biological evolution of the language faculty: under a number of reasonable scenarios, cultural evolution can shield the language faculty from selection, such that strongly constraining language-specific learning biases are unlikely to evolve. We therefore argue that language is best seen as a consequence of cultural evolution in populations with a weak and/or domain-general language faculty. PMID:18801718

  3. The Path of the Blind Watchmaker: A Model of Evolution

    OpenAIRE

    Poggio, Andrew Anthony

    2011-01-01

    Evolution has been described by Richard Dawkins as a blind watchmaker due to its being unconscious and random but selective and able to produce complex forms. Evolution from an early, primitive organism (the Last Universal Common Ancestor of all life, LUCA) to Homo sapiens is the most dramatic biological process that has taken place on Earth and knowledge of it is important to understanding many aspects of biology including disease prevention and treatment.We claim that computational biology ...

  4. Teaching Evolution: A Heuristic Study of Personal and Cultural Dissonance

    Science.gov (United States)

    Grimes, Larry G.

    Darwinian evolution is a robustly supported scientific theory. Yet creationists continue to challenge its teaching in American public schools. Biology teachers in all 50 states are responsible for teaching science content standards that include evolution. As products of their backgrounds and affiliations teachers bring personal attitudes and beliefs to their teaching. The purpose of this study was to explore how biology teachers perceive, describe, and value their teaching of evolution. This research question was explored through a heuristic qualitative methodology. Eight veteran California high school biology teachers were queried as to their beliefs, perceptions, experiences and practices of teaching evolution. Both personal and professional documents were collected. Data was presented in the form of biographical essays that highlight teachers' backgrounds, experiences, perspectives and practices of teaching evolution. Of special interest was how they describe pressure over teaching evolution during a decade of standards and No Child Left Behind high-stakes testing mandates. Five common themes emerged. Standards have increased the overall amount of evolution that is taught. High-stakes testing has decreased the depth at which evolution is taught. Teacher belief systems strongly influence how evolution is taught. Fear of creationist challenges effect evolution teaching strategies. And lastly, concern over the potential effects of teaching evolution on student worldviews was mixed. Three categories of teacher concern over the potential impact of evolution on student worldviews were identified: Concerned, Strategist, and Carefree. In the final analysis teacher beliefs and attitudes still appeared to he the most important factor influencing how evolution is taught.

  5. Mesoscopic biology

    Indian Academy of Sciences (India)

    G V Shivashankar

    2002-02-01

    In this paper we present a qualitative outlook of mesoscopic biology where the typical length scale is of the order of nanometers and the energy scales comparable to thermal energy. Novel biomolecular machines, governed by coded information at the level of DNA and proteins, operate at these length scales in biological systems. In recent years advances in technology have led to the study of some of the design principles of these machines; in particular at the level of an individual molecule. For example, the forces that operate in molecular interactions, the stochasticity involved in these interactions and their spatio-temporal dynamics are beginning to be explored. Understanding such design principles is opening new possibilities in mesoscopic physics with potential applications.

  6. Collective Landmarks for Deep Time: A New Tool for Evolution Education

    Science.gov (United States)

    Delgado, Cesar

    2014-01-01

    Evolution is a fundamental, organising concept in biology, yet there is widespread resistance to evolution among US students and there are rising creationist challenges in Europe. Resistance to evolution is linked to lack of understanding of the age of the Earth. An understanding of deep time is thus essential for effective biology education.…

  7. Which Beak Fits the Bill? An Activity Examining Adaptation, Natural Selection and Evolution

    Science.gov (United States)

    Darling, Randi

    2014-01-01

    Evolution is a unifying concept within biology. In fact, Dobzhansky, a noted evolutionary biologist, argued, "Nothing in biology makes sense except in the light of evolution" (Dobzhansky, 1973). However, often students have misconceptions about evolution. There are a number of available activities where students use tools (representing…

  8. Biological programming

    OpenAIRE

    Ramsden, Jeremy J.; Bándi, Gergely

    2010-01-01

    Biology offers a tremendous set of concepts that are potentially very powerfully usable for the software engineer, but they have been barely exploited hitherto. In this position paper we propose a fresh attempt to create the building blocks of a programming technology that could be as successful as life. A key guiding principle is to develop and make use of unambiguous definitions of the essential features of life.

  9. Biological radioprotector

    International Nuclear Information System (INIS)

    According to the patent description, the biological radioprotector is deuterium depleted water, DDW, produced by vacuum distillation with an isotopic content lower than natural value. It appears as such or in a mixture with natural water and carbon dioxide. It can be used for preventing and reducing the ionizing radiation effects upon humans or animal organisms, exposed therapeutically, professionally or accidentally to radiation. The most significant advantage of using DDW as biological radioprotector results from its way of administration. Indeed no one of the radioprotectors currently used today can be orally administrated, what reduces the patients' compliance to prophylactic administrations. The biological radioprotector is an unnoxious product obtained from natural water, which can be administrated as food additive instead of drinking water. Dose modification factor is according to initial estimates around 1.9, what is a remarkable feature when one takes into account that the product is toxicity-free and side effect-free and can be administrated prophylactically as a food additive. A net radioprotective action of the deuterium depletion was evidenced experimentally in laboratory animals (rats) hydrated with DDW of 30 ppm D/(D+H) concentration as compared with normally hydrated control animals. Knowing the effects of irradiation and mechanisms of the acute radiation disease as well as the effects of administration of radiomimetic chemicals upon cellular lines of fast cell division, it appears that the effects of administrating DDW result from stimulation of the immunity system. In conclusion, the biological radioprotector DDW presents the following advantages: - it is obtained from natural products without toxicity; - it is easy to be administrated as a food additive, replacing the drinking water; - besides radioprotective effects, the product has also immunostimulative and antitumoral effects

  10. Photon track evolution

    International Nuclear Information System (INIS)

    Given the time scale of biological, biochemical, biophysical and physical effects in a radiation exposure of living tissue, the first physical stage can be considered to be independent of time. All the physical interactions caused by the incident photons happen at the same starting time. From this point of view it would seem that the evolution of photon tracks is not a relevant topic for analysis; however, if the photon track is considered as a sequence of several interactions, there are several steps until the total degradation of the energy of the primary photon. We can characterise the photon track structure by the probability p(E,j), that is, the probability that a photon with energy E suffers j secondary interactions. The aim of this work is to analyse the photon track structure by considering j as a step of the photon track evolution towards the total degradation of the photon energy. Low energy photons (<150 keV) are considered, with water phantoms and half-extended geometry. The photon track evolution concept is presented and compared with the energy deposition along the track and also with the spatial distribution of the several steps in the photon track. (authors)

  11. The middle way of evolution

    OpenAIRE

    Hunt, Tam

    2012-01-01

    This essay provides a critical review of two recent books on evolution: Richard Dawkins’ The Greatest Show on Earth, and Jerry Coyne’s Why Evolution is True, as well as a critique of mainstream evolutionary theory and of natural selection. I also suggest a generalization of sexual selection theory that acknowledges mind as pervasive in nature. Natural selection, as the primary theory of how biological change occurs, must be carefully framed to avoid the long-standing “tautology problem” and m...

  12. Marine biology

    International Nuclear Information System (INIS)

    This book discusses both taxonomic and ecological topics on marine biology. Full coverage of marine organisms of all five kingdoms is provided, along with interesting and thorough discussion of all major marine habitats. Organization into six major parts allows flexibility. It also provides insight into important topics such as disposal of nuclear waste at sea, the idea that life began on the ocean floor, and how whales, krill, and people interact. A full-color photo chapter reviews questions, and exercises. The contents are: an overview marine biology: fundamental concepts/investigating life in the ocean; the physical ocean, the ocean floor, the nature of water, the nature and motion of ocean water; general ecology, conditions for life in the sea, biological productivity and energy transfer; marine organisms; monera, protista, mycota and metaphyta; the smaller marine animals, the large animals marine habitats, the intertidal zone/benthos of the continental shelf, the photic zone, the deep ocean, the ocean under stress, marine pollution, appendix a: the metric system and conversion factors/ appendix b: prefixes and suffixes/ appendix c: taxonomic classification of common marine organisms, and glossary, and index

  13. Marine biology

    Energy Technology Data Exchange (ETDEWEB)

    Thurman, H.V.; Webber, H.H.

    1984-01-01

    This book discusses both taxonomic and ecological topics on marine biology. Full coverage of marine organisms of all five kingdoms is provided, along with interesting and thorough discussion of all major marine habitats. Organization into six major parts allows flexibility. It also provides insight into important topics such as disposal of nuclear waste at sea, the idea that life began on the ocean floor, and how whales, krill, and people interact. A full-color photo chapter reviews questions, and exercises. The contents are: an overview marine biology: fundamental concepts/investigating life in the ocean; the physical ocean, the ocean floor, the nature of water, the nature and motion of ocean water; general ecology, conditions for life in the sea, biological productivity and energy transfer; marine organisms; monera, protista, mycota and metaphyta; the smaller marine animals, the large animals marine habitats, the intertidal zone/benthos of the continental shelf, the photic zone, the deep ocean, the ocean under stress, marine pollution, appendix a: the metric system and conversion factors/ appendix b: prefixes and suffixes/ appendix c: taxonomic classification of common marine organisms, and glossary, and index.

  14. Some nonlinear challenges in biology

    International Nuclear Information System (INIS)

    Driven by a deluge of data, biology is undergoing a transition to a more quantitative science. Making sense of the data, building new models, asking the right questions and designing smart experiments to answer them are becoming ever more relevant. In this endeavour, nonlinear approaches can play a fundamental role. The biochemical reactions that underlie life are very often nonlinear. The functional features exhibited by biological systems at all levels (from the activity of an enzyme to the organization of a colony of ants, via the development of an organism or a functional module like the one responsible for chemotaxis in bacteria) are dynamically robust. They are often unaffected by order of magnitude variations in the dynamical parameters, in the number or concentrations of actors (molecules, cells, organisms) or external inputs (food, temperature, pH, etc). This type of structural robustness is also a common feature of nonlinear systems, exemplified by the fundamental role played by dynamical fixed points and attractors and by the use of generic equations (logistic map, Fisher–Kolmogorov equation, the Stefan problem, etc.) in the study of a plethora of nonlinear phenomena. However, biological systems differ from these examples in two important ways: the intrinsic stochasticity arising from the often very small number of actors and the role played by evolution. On an evolutionary time scale, nothing in biology is frozen. The systems observed today have evolved from solutions adopted in the past and they will have to adapt in response to future conditions. The evolvability of biological system uniquely characterizes them and is central to biology. As the great biologist T Dobzhansky once wrote: 'nothing in biology makes sense except in the light of evolution'. (open problem)

  15. Mitochondrial Evolution

    OpenAIRE

    Gray, Michael W

    2012-01-01

    Viewed through the lens of the genome it contains, the mitochondrion is of unquestioned bacterial ancestry, originating from within the bacterial phylum α-Proteobacteria (Alphaproteobacteria). Accordingly, the endosymbiont hypothesis—the idea that the mitochondrion evolved from a bacterial progenitor via symbiosis within an essentially eukaryotic host cell—has assumed the status of a theory. Yet mitochondrial genome evolution has taken radically different pathways in diverse eukaryotic lineag...

  16. Biological Databases

    Directory of Open Access Journals (Sweden)

    Kaviena Baskaran

    2013-12-01

    Full Text Available Biology has entered a new era in distributing information based on database and this collection of database become primary in publishing information. This data publishing is done through Internet Gopher where information resources easy and affordable offered by powerful research tools. The more important thing now is the development of high quality and professionally operated electronic data publishing sites. To enhance the service and appropriate editorial and policies for electronic data publishing has been established and editors of article shoulder the responsibility.

  17. Evolution algebras generated by Gibbs measures

    International Nuclear Information System (INIS)

    In this article we study algebraic structures of function spaces defined by graphs and state spaces equipped with Gibbs measures by associating evolution algebras. We give a constructive description of associating evolution algebras to the function spaces (cell spaces) defined by graphs and state spaces and Gibbs measure μ. For finite graphs we find some evolution subalgebras and other useful properties of the algebras. We obtain a structure theorem for evolution algebras when graphs are finite and connected. We prove that for a fixed finite graph, the function spaces have a unique algebraic structure since all evolution algebras are isomorphic to each other for whichever Gibbs measures are assigned. When graphs are infinite graphs then our construction allows a natural introduction of thermodynamics in studying of several systems of biology, physics and mathematics by theory of evolution algebras. (author)

  18. Life and evolution as physics.

    Science.gov (United States)

    Bejan, Adrian

    2016-01-01

    What is evolution and why does it exist in the biological, geophysical and technological realms - in short, everywhere? Why is there a time direction - a time arrow - in the changes we know are happening every moment and everywhere? Why is the present different than the past? These are questions of physics, about everything, not just biology. The answer is that nothing lives, flows and moves unless it is driven by power. Physics sheds light on the natural engines that produce the power destroyed by the flows, and on the free morphing that leads to flow architectures naturally and universally. There is a unifying tendency across all domains to evolve into flow configurations that provide greater access for movement. This tendency is expressed as the constructal law of evolutionary flow organization everywhere. Here I illustrate how this law of physics accounts for and unites the life and evolution phenomena throughout nature, animate and inanimate. PMID:27489579

  19. Biological biomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Jorge-Herrero, E. [Servicio de Cirugia Experimental. Clinica Puerta de Hierro, Madrid (Spain)

    1997-05-01

    There are a number of situations in which substances of biological origin are employed as biomaterials. Most of them are macromolecules derived from isolated connective tissue or the connective tissue itself in membrane form, in both cases, the tissue can be used in its natural form or be chemically treated. In other cases, certain blood vessels can be chemically pretreated and used as vascular prostheses. Proteins such as albumin, collagen and fibrinogen are employed to coat vascular prostheses. Certain polysaccharides have also been tested for use in controlled drug release systems. Likewise, a number of tissues, such as dura mater, bovine pericardium, procine valves and human valves, are used in the preparation of cardiac prostheses. We also use veins from animals or humans in arterial replacement. In none of these cases are the tissues employed dissimilar to the native tissues as they have been chemically modified, becoming a new bio material with different physical and biochemical properties. In short, we find that natural products are being utilized as biomaterials and must be considered as such; thus, it is necessary to study both their chemicobiological and physicomechanical properties. In the present report, we review the current applications, problems and future prospects of some of these biological biomaterials. (Author) 84 refs.

  20. Rapid Evolution of Social Learning

    OpenAIRE

    Nunn, Charles Lindsay; Franz, M.

    2009-01-01

    Culture is widely thought to be beneficial when social learning is less costly than individual learning and thus may explain the enormous ecological success of humans. Rogers (1988. Does biology constrain culture. Am. Anthropol. 90: 819–831) contradicted this common view by showing that the evolution of social learning does not necessarily increase the net benefits of learned behaviours in a variable environment. Using simulation experiments, we re-analysed extensions of Rogers' model after r...

  1. Evidence and Evolution: A Review

    OpenAIRE

    Robert, Christian P.

    2010-01-01

    "Evidence and Evolution: the Logic behind the Science" was published in 2008 by Elliott Sober. It examines the philosophical foundations of the statistical arguments used to evaluate hypotheses in evolutionary biology, based on simple examples and likelihood ratios. The difficulty with reading the book from a statistician's perspective is the reluctance of the author to engage into model building and even less into parameter estimation. The first chapter nonetheless constitutes a splendid cov...

  2. Emerging principles of regulatory evolution

    OpenAIRE

    Prud'homme, Benjamin; Gompel, Nicolas; Carroll, Sean B.

    2007-01-01

    Understanding the genetic and molecular mechanisms governing the evolution of morphology is a major challenge in biology. Because most animals share a conserved repertoire of body-building and -patterning genes, morphological diversity appears to evolve primarily through changes in the deployment of these genes during development. The complex expression patterns of developmentally regulated genes are typically controlled by numerous independent cis-regulatory elements (CREs). It has been prop...

  3. Extinction Events Can Accelerate Evolution

    DEFF Research Database (Denmark)

    Lehman, Joel; Miikkulainen, Risto

    2015-01-01

    Extinction events impact the trajectory of biological evolution significantly. They are often viewed as upheavals to the evolutionary process. In contrast, this paper supports the hypothesis that although they are unpredictably destructive, extinction events may in the long term accelerate...... evolution by increasing evolvability. In particular, if extinction events extinguish indiscriminately many ways of life, indirectly they may select for the ability to expand rapidly through vacated niches. Lineages with such an ability are more likely to persist through multiple extinctions. Lending...... computational support for this hypothesis, this paper shows how increased evolvability will result from simulated extinction events in two computational models of evolved behavior. The conclusion is that although they are destructive in the short term, extinction events may make evolution more prolific in the...

  4. Human evolution: humanistic selection and looking to the future.

    Science.gov (United States)

    Krsiak, Miloslav

    2006-10-01

    Cultural evolution has predominated over biological evolution in modern man (Homo sapiens sapiens). Cultural evolution differs from biological evolution not only by inheritance of acquired characteristics but also, as is proposed in the present essay, by another kind of selection mechanism. Whereas selection in biological evolution is executed according to a criterion of reproductive success (the natural selection), selection in cultural evolution appears to be carried out according to human and humanistic criteria (success or fitness in meeting human needs, interests and humanistic values--"humanistic selection"). Many humanistic needs or values do not seem to be prerequisite for reproductive success, yet some of them (e.g. a need for freedom) seem to be inborn. Innateness, humanistic selection (decisive at a community level) and hierarchy of some human needs, interests and values appear to give cultural evolution a generally upward trend although long periods of stagnation or even regression may occur. Modern humans appear to be still at the early stage of their cultural evolution. A further cultural evolution of man appears to be, in contrast to biological evolution, predictable (with an optimistic outlook) and testable. The problem is that the hopeful result of this test will probably be known only in the fairly remote future provided that this species will not become extinct before that. PMID:17159825

  5. Implementing Recommendations for Introductory Biology by Writing a New Textbook

    OpenAIRE

    Barsoum, Mark J.; Sellers, Patrick J.; Campbell, A. Malcolm; Heyer, Laurie J.; Paradise, Christopher J

    2013-01-01

    We redesigned the undergraduate introductory biology course by writing a new textbook (Integrating Concepts in Biology [ICB]) that follows first principles of learning. Our approach emphasizes primary data interpretation and the utility of mathematics in biology, while de-emphasizing memorization. This redesign divides biology into five big ideas (information, evolution, cells, emergent properties, homeostasis), addressing each at five levels of organization (molecules, cells, organisms, popu...

  6. LA (R EVOLUCIÓN INFORMÁTICA EN BIOLOGÍA:: EL CASO DE LA GENÓMICA The Informatics (R Evolution in Biology:: The Case of Genomics

    Directory of Open Access Journals (Sweden)

    LAYLA MICHÁN AGUIRRE

    Full Text Available La biología ha evolucionado rápidamente en las últimas décadas; uno de los indicadores de este fenómeno ha sido la introducción de nuevas disciplinas, tal es el caso de la genómica que se originó en la década de los años 80 y ha dado un giro inverosímil a la ciencia moderna, dicha disciplina hace referencia al estudio no solo de los genes, sino de sus funciones, relaciones entre sí y con el medio ambiente. Surgió con la consolidación del proyecto genoma humano en un periodo de transición donde el conocimiento genético específico se tornó crítico. Se diferencia de otros enfoques (por ejemplo: la ecología, la biología evolutiva en el tipo de información que ofrece, las perspectivas de mejoras técnicas e intelectuales en la obtención y explotación de datos de todo el ge-noma (Murray, 2000. Presentamos un breve análisis bibliométrico en el que se muestra el desarrollo y las principales tendencias de esta disciplina biológica en boga.Biology has been revolutionized by the introduction of new disciplines, such is the case of genomics that introduced in the 80s has turned unlikely to modern science, the discipline refers to the study not only of genes but their roles, relations among themselves and with the environment. Arises, with the consolidation of the Human Genome Project and introduces us to a period of transition in which specific genetic knowledge becomes critical. Differs from other approaches in the type of information provided, the prospects for technical and intellectual improvements in the collection and use of data from the whole genome. A brief bibliometric analysis which shows the development and the main trends of this biological discipline in vogue.

  7. Adaptive evolution in ecological communities.

    Directory of Open Access Journals (Sweden)

    Martin M Turcotte

    Full Text Available Understanding how natural selection drives evolution is a key challenge in evolutionary biology. Most studies of adaptation focus on how a single environmental factor, such as increased temperature, affects evolution within a single species. The biological relevance of these experiments is limited because nature is infinitely more complex. Most species are embedded within communities containing many species that interact with one another and the physical environment. To understand the evolutionary significance of such ecological complexity, experiments must test the evolutionary impact of interactions among multiple species during adaptation. Here we highlight an experiment that manipulates species composition and tracks evolutionary responses within each species, while testing for the mechanisms by which species interact and adapt to their environment. We also discuss limitations of previous studies of adaptive evolution and emphasize how an experimental evolution approach can circumvent such shortcomings. Understanding how community composition acts as a selective force will improve our ability to predict how species adapt to natural and human-induced environmental change.

  8. Biological effects

    International Nuclear Information System (INIS)

    Following an introduction into the field of cellular radiation effect considering the most important experimental results, the biological significance of the colony formation ability is brought out. The inactivation concept of stem cells does not only prove to be good, according to the present results, in the interpretation of the pathogenesis of acute radiation effects on moult tissue, it also enables chronicle radiation injuries to be interpreted through changes in the fibrous part of the organs. Radiation therapy of tumours can also be explained to a large extent by the radiation effect on the unlimited reproductiveness of tumour cells. The more or less similar dose effect curves for healthy and tumour tissue in practice lead to intermittent irradiation. The dependence of the intermittent doses and intervals on factors such as Elkind recovery, synchronisation, redistribution, reoxygenation, repopulation and regeneration are reviewed. (ORU/LH)

  9. Creating biological nanomaterials using synthetic biology

    International Nuclear Information System (INIS)

    Synthetic biology is a new discipline that combines science and engineering approaches to precisely control biological networks. These signaling networks are especially important in fields such as biomedicine and biochemical engineering. Additionally, biological networks can also be critical to the production of naturally occurring biological nanomaterials, and as a result, synthetic biology holds tremendous potential in creating new materials. This review introduces the field of synthetic biology, discusses how biological systems naturally produce materials, and then presents examples and strategies for incorporating synthetic biology approaches in the development of new materials. In particular, strategies for using synthetic biology to produce both organic and inorganic nanomaterials are discussed. Ultimately, synthetic biology holds the potential to dramatically impact biological materials science with significant potential applications in medical systems. (review)

  10. Creating biological nanomaterials using synthetic biology

    Directory of Open Access Journals (Sweden)

    MaryJoe K Rice

    2014-01-01

    Full Text Available Synthetic biology is a new discipline that combines science and engineering approaches to precisely control biological networks. These signaling networks are especially important in fields such as biomedicine and biochemical engineering. Additionally, biological networks can also be critical to the production of naturally occurring biological nanomaterials, and as a result, synthetic biology holds tremendous potential in creating new materials. This review introduces the field of synthetic biology, discusses how biological systems naturally produce materials, and then presents examples and strategies for incorporating synthetic biology approaches in the development of new materials. In particular, strategies for using synthetic biology to produce both organic and inorganic nanomaterials are discussed. Ultimately, synthetic biology holds the potential to dramatically impact biological materials science with significant potential applications in medical systems.

  11. CHEMICAL EVOLUTION

    Energy Technology Data Exchange (ETDEWEB)

    Calvin, Melvin

    1965-06-01

    How did life come to be on the surface of the earth? Darwin himself recognized that his basic idea of evolution by variation and natural selection must be a continuous process extending backward in time through that period in which the first living things arose and into the period of 'Chemical Evolution' which preceded it. We are approaching the examination of these events by two routes. One is to seek for evidence in the ancient rocks of the earth which were laid down prior to that time in which organisms capable of leaving their skeletons in the rocks to be fossilized were in existence. This period is sometime prior to approximately 600 million years ago. The earth is believed to have taken its present form approximately 4700 million years ago. We have found in rocks whose age is about 1000 million years certain organic molecules which are closely related to the green pigment of plants, chlorophyll. This seems to establish that green plants were already fluorishing prior to that time. We have now found in rocks of still greater age, namely, 2500 million years, the same kinds of molecules mentioned above which can be attributed to the presence of living organisms. If these molecules are as old as the rocks, we have thus shortened the time available for the generation of the complex biosynthetic sequences which give rise to these specific hydrocarbons (polyisoprenoids) to less than 2000 million years.

  12. Energy utilization in fluctuating biological energy converters

    OpenAIRE

    Szőke, Abraham; Hajdu, Janos

    2016-01-01

    We have argued previously [Szoke et al., FEBS Lett. 553, 18–20 (2003); Curr. Chem. Biol. 1, 53–57 (2007)] that energy utilization and evolution are emergent properties based on a small number of established laws of physics and chemistry. The relevant laws constitute a framework for biology on a level intermediate between quantum chemistry and cell biology. There are legitimate questions whether these concepts are valid at the mesoscopic level. Such systems fluctuate appreciably, so it is not ...

  13. Evolution of cooperation in artificial ants

    OpenAIRE

    Waibel, Markus

    2007-01-01

    The evolution of cooperation is a fundamental and enduring puzzle in biology and the social sciences. Hundreds of theoretical models have been proposed, but empirical research has been hindered by the generation time of social organisms and by the difficulties of quantifying costs and benefits of cooperation. The significant increase in computational power in the last decade has made artificial evolution of simple social robots a promising alternative. This thesis is concerned with the artifi...

  14. Simple models of evolution and extinction

    CERN Document Server

    Newman, M E J

    1999-01-01

    This article gives a brief introduction to the mathematical modeling of large-scale biological evolution and extinction. We give three examples of simple models in this field: the coevolutionary avalanche model of Bak and Sneppen, the environmental stress model of Newman, and the increasing fitness model of Sibani, Schmidt, and Alstrom. We describe the features of real evolution which these models are intended to explain and compare the results of simulations against data drawn from the fossil record.

  15. Simple models of evolution and extinction

    OpenAIRE

    Newman, M. E. J.

    1999-01-01

    This article gives a brief introduction to the mathematical modeling of large-scale biological evolution and extinction. We give three examples of simple models in this field: the coevolutionary avalanche model of Bak and Sneppen, the environmental stress model of Newman, and the increasing fitness model of Sibani, Schmidt, and Alstrom. We describe the features of real evolution which these models are intended to explain and compare the results of simulations against data drawn from the fossi...

  16. The evolution of photosynthesis…again?

    OpenAIRE

    Rothschild, Lynn J.

    2008-01-01

    ‘Replaying the tape’ is an intriguing ‘would it happen again?’ exercise. With respect to broad evolutionary innovations, such as photosynthesis, the answers are central to our search for life elsewhere. Photosynthesis permits a large planetary biomass on Earth. Specifically, oxygenic photosynthesis has allowed an oxygenated atmosphere and the evolution of large metabolically demanding creatures, including ourselves. There are at least six prerequisites for the evolution of biological carbon f...

  17. Entrepreneurship, evolution and the human mind

    OpenAIRE

    Brian J. Loasby

    2005-01-01

    Schumpeterian 'development from within' requires imagination, skill and motivation; so does Cattaneo's 'psychology of wealth'. Neither can be encompassed by models that rely on deductive rationality, but are twin products of Knightian uncertainty, where the absence of demonstrably correct procedures allows individuals to create domain-limited mental structures. The human mind (as studied by Smith, Marshall and Hayek), is a product of biological evolution which supports the evolution of knowle...

  18. The Evolution of Reduced Microbial Killing

    OpenAIRE

    Vriezen, Jan A. C.; Valliere, Michael; Riley, Margaret A.

    2009-01-01

    Bacteria engage in a never-ending arms race in which they compete for limited resources and niche space. The outcome of this intense interaction is the evolution of a powerful arsenal of biological weapons. Perhaps the most studied of these are colicins, plasmid-based toxins produced by and active against Escherichia coli. The present study was designed to explore the molecular responses of a colicin-producing strain during serial transfer evolution. What evolutionary changes occur when colic...

  19. Structural Biology Fact Sheet

    Science.gov (United States)

    ... Home > Science Education > Structural Biology Fact Sheet Structural Biology Fact Sheet Tagline (Optional) Middle/Main Content Area What is structural biology? Structural biology is a field of science focused ...

  20. New Frontiers in Language Evolution and Development.

    Science.gov (United States)

    Oller, D Kimbrough; Dale, Rick; Griebel, Ulrike

    2016-04-01

    This article introduces the Special Issue and its focus on research in language evolution with emphasis on theory as well as computational and robotic modeling. A key theme is based on the growth of evolutionary developmental biology or evo-devo. The Special Issue consists of 13 articles organized in two sections: A) Theoretical foundations and B) Modeling and simulation studies. All the papers are interdisciplinary in nature, encompassing work in biological and linguistic foundations for the study of language evolution as well as a variety of computational and robotic modeling efforts shedding light on how language may be developed and may have evolved. PMID:27120154

  1. Simulating Biological and Non-Biological Motion

    Science.gov (United States)

    Bruzzo, Angela; Gesierich, Benno; Wohlschlager, Andreas

    2008-01-01

    It is widely accepted that the brain processes biological and non-biological movements in distinct neural circuits. Biological motion, in contrast to non-biological motion, refers to active movements of living beings. Aim of our experiment was to investigate the mechanisms underlying mental simulation of these two movement types. Subjects had to…

  2. A Brief Introduction to Chinese Biological Biological

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Chinese Biological Abstracts sponsored by the Library, the Shanghai Institutes for Biological Sciences, the Biological Documentation and Information Network, all of the Chinese Academy of Sciences, commenced publication in 1987 and was initiated to provide access to the Chinese information in the field of biology.

  3. Ultrastructure, macromolecules, and evolution

    CERN Document Server

    Dillon, Lawrence S

    1981-01-01

    Thus far in the history of biology, two, and only two, fundamental principles have come to light that pervade and unify the entire science-the cell theory and the concept of evolution. While it is true that recently opened fields of inves­ tigation have given rise to several generalizations of wide impact, such as the universality of DNA and the energetic dynamics of ecology, closer inspection reveals them to be part and parcel of either of the first two mentioned. Because in the final analysis energy can act upon an organism solely at the cellular level, its effects may be perceived basically to represent one facet of cell me­ tabolism. Similarly, because the DNA theory centers upon the means by which cells build proteins and reproduce themselves, it too proves to be only one more, even though an exciting, aspect of the cell theory. In fact, if the matter is given closer scrutiny, evolution itself can be viewed as being a fundamental portion of the cell concept, for its effects arise only as a consequence ...

  4. Community Evolution

    CERN Document Server

    Bródka, Piotr; Kazienko, Przemysław

    2016-01-01

    The continuous interest in the social network area contributes to the fast development of this field. The new possibilities of obtaining and storing data facilitate deeper analysis of the entire social network, extracted social groups and single individuals as well. One of the most interesting research topic is the network dynamics and dynamics of social groups in particular, it means analysis of group evolution over time. It is the natural step forward after social community extraction. Having communities extracted, appropriate knowledge and methods for dynamic analysis may be applied in order to identify changes as well as to predict the future of all or some selected groups. Furthermore, knowing the most probably change of a given group some additional steps may be performed in order to change this predicted future according to specific needs. Such ability would be a powerful tool in the hands of human resource managers, personnel recruitment, marketing, telecommunication companies, etc.

  5. Phenotypic Evolution With and Beyond Genome Evolution.

    Science.gov (United States)

    Félix, M-A

    2016-01-01

    DNA does not make phenotypes on its own. In this volume entitled "Genes and Phenotypic Evolution," the present review draws the attention on the process of phenotype construction-including development of multicellular organisms-and the multiple interactions and feedbacks between DNA, organism, and environment at various levels and timescales in the evolutionary process. First, during the construction of an individual's phenotype, DNA is recruited as a template for building blocks within the cellular context and may in addition be involved in dynamical feedback loops that depend on the environmental and organismal context. Second, in the production of phenotypic variation among individuals, stochastic, environmental, genetic, and parental sources of variation act jointly. While in controlled laboratory settings, various genetic and environmental factors can be tested one at a time or in various combinations, they cannot be separated in natural populations because the environment is not controlled and the genotype can rarely be replicated. Third, along generations, genotype and environment each have specific properties concerning the origin of their variation, the hereditary transmission of this variation, and the evolutionary feedbacks. Natural selection acts as a feedback from phenotype and environment to genotype. This review integrates recent results and concrete examples that illustrate these three points. Although some themes are shared with recent calls and claims to a new conceptual framework in evolutionary biology, the viewpoint presented here only means to add flesh to the standard evolutionary synthesis. PMID:27282029

  6. Teaching evolution: challenging religious preconceptions.

    Science.gov (United States)

    Lovely, Eric C; Kondrick, Linda C

    2008-08-01

    Teaching college students about the nature of science should not be a controversial exercise. College students are expected to distinguish between astronomy and astrology, chemistry and alchemy, evolution and creationism. In practice, however, the conflict between creationism and the nature of science may create controversy in the classroom, even walkouts, when the subject of evolution is raised. The authors have grappled with the meaning of such behaviors. They surveyed 538 students in a public, liberal arts college. Pre/post course surveys were analyzed to track changes in student responses to questions that were either consistent or inconsistent with the Theory of Evolution after a semester of instruction in a college biology or zoology course in which evolution was taught. Many students who were initially undecided about issues regarding evolution had shifted in their viewpoints by the end of the course. It was found that more education about the evidence for and the mechanics of evolutionary processes did not necessarily move students toward a scientific viewpoint. The authors also discovered a "wedge" effect among students who were undecided about questions pertaining to human ancestry at the beginning of the course. About half of these students shifted to a scientific viewpoint at the end of the course; the other half shifted toward agreement with statements consistent with creationism. PMID:21669781

  7. Synthetic Evolution of Metabolic Productivity Using Biosensors.

    Science.gov (United States)

    Williams, Thomas C; Pretorius, Isak S; Paulsen, Ian T

    2016-05-01

    Synthetic biology has progressed to the point where genes that encode whole metabolic pathways and even genomes can be manufactured and brought to life. This impressive ability to synthesise and assemble DNA is not yet matched by an ability to predictively engineer biology. These difficulties exist because biological systems are often overwhelmingly complex, having evolved to facilitate growth and survival rather than specific engineering objectives such as the optimisation of biochemical production. A promising and revolutionary solution to this problem is to harness the process of evolution to create microbial strains with desired properties. The tools of systems biology can then be applied to understand the principles of biological design, bringing synthetic biology closer to becoming a predictive engineering discipline. PMID:26948437

  8. Creating biological nanomaterials using synthetic biology

    OpenAIRE

    MaryJoe K Rice; Ruder, Warren C.

    2014-01-01

    Synthetic biology is a new discipline that combines science and engineering approaches to precisely control biological networks. These signaling networks are especially important in fields such as biomedicine and biochemical engineering. Additionally, biological networks can also be critical to the production of naturally occurring biological nanomaterials, and as a result, synthetic biology holds tremendous potential in creating new materials. This review introduces the field of synthetic bi...

  9. Are There Laws of Genome Evolution?

    OpenAIRE

    Koonin, Eugene V

    2011-01-01

    Research in quantitative evolutionary genomics and systems biology led to the discovery of several universal regularities connecting genomic and molecular phenomic variables. These universals include the log-normal distribution of the evolutionary rates of orthologous genes; the power law–like distributions of paralogous family size and node degree in various biological networks; the negative correlation between a gene's sequence evolution rate and expression level; and differential scaling o...

  10. Are there laws of genome evolution?

    OpenAIRE

    Koonin, Eugene V.

    2011-01-01

    Research in quantitative evolutionary genomics and systems biology led to the discovery of several universal regularities connecting genomic and molecular phenomic variables. These universals include the log-normal distribution of the evolutionary rates of orthologous genes; the power law-like distributions of paralogous family size and node degree in various biological networks; the negative correlation between a gene's sequence evolution rate and expression level; and differential scaling o...

  11. Thermodynamical journey in plant biology

    Directory of Open Access Journals (Sweden)

    Adelin eBarbacci

    2015-06-01

    Full Text Available Nonequilibrium irreversible thermodynamics constitute a meaningful point of view suitable to explore life with a rich paradigm. This analytical framework can be used to span the gap from molecular processes to plant function and shows great promise to create a holistic description of life. Since living organisms dissipate energy, exchange entropy and matter with their environment, they can be assimilated to dissipative structures. This concept inherited from nonequilibrium thermodynamics has four properties which defines a scale independent framework suitable to provide a simpler and more comprehensive view of the highly complex plant biology. According to this approach, a biological process is modeled as an avalanche of dissipative structures. Each dissipative structure, corresponds to an unitary biological process, which is initiated by the amplification of a fluctuation. Evolution of the process leads to the breakage of the system symmetry and to the export of entropy. Exporting entropy to the surrounding environment corresponds to collecting information about it. Biological actors which break the symmetry of the system and which store information are by consequence, key actors on which experiments and data analysis focus most. This paper aims at illustrating properties of dissipative structure through familiar examples and thus initiating the dialogue between nonequilibrium thermodynamics and plant biology.

  12. Cyanobacterial evolution during the Precambrian

    Science.gov (United States)

    Schirrmeister, Bettina E.; Sanchez-Baracaldo, Patricia; Wacey, David

    2016-07-01

    Life on Earth has existed for at least 3.5 billion years. Yet, relatively little is known of its evolution during the first two billion years, due to the scarceness and generally poor preservation of fossilized biological material. Cyanobacteria, formerly known as blue green algae were among the first crown Eubacteria to evolve and for more than 2.5 billion years they have strongly influenced Earth's biosphere. Being the only organism where oxygenic photosynthesis has originated, they have oxygenated Earth's atmosphere and hydrosphere, triggered the evolution of plants -being ancestral to chloroplasts- and enabled the evolution of complex life based on aerobic respiration. Having such a strong impact on early life, one might expect that the evolutionary success of this group may also have triggered further biosphere changes during early Earth history. However, very little is known about the early evolution of this phylum and ongoing debates about cyanobacterial fossils, biomarkers and molecular clock analyses highlight the difficulties in this field of research. Although phylogenomic analyses have provided promising glimpses into the early evolution of cyanobacteria, estimated divergence ages are often very uncertain, because of vague and insufficient tree-calibrations. Results of molecular clock analyses are intrinsically tied to these prior calibration points, hence improving calibrations will enable more precise divergence time estimations. Here we provide a review of previously described Precambrian microfossils, biomarkers and geochemical markers that inform upon the early evolution of cyanobacteria. Future research in micropalaeontology will require novel analyses and imaging techniques to improve taxonomic affiliation of many Precambrian microfossils. Consequently, a better understanding of early cyanobacterial evolution will not only allow for a more specific calibration of cyanobacterial and eubacterial phylogenies, but also provide new dates for the tree

  13. Ecology, Evolution, and Animal Behavior (EBB)

    OpenAIRE

    Bradley, Gordon

    2008-01-01

    As discussed in Chapter 2 of Kendall’s thesis, there is a subfield of biology called Ecology, Evolution, and Animal Behavior that is sometimes called Ecology, Evolution, and Behavior with both abbreviated as EEB. Some universities have Departments with this name and it is a well establish field of research. “Ecology is ‘the study of the interrelationships between organisms and their natural environment, both living and nonliving.’ .... Evolution is ‘the gradual process by which th...

  14. Ascovirus and its Evolution

    Institute of Scientific and Technical Information of China (English)

    Xiao-Wen Cheng; Xiu-Feng Wan; Jianli Xue; Richard C. Moore

    2007-01-01

    Ascoviruses, iridoviruses, asfarviruses and poxviruses are all cytoplasmic DNA viruses. The evolutionary origins of cytoplasmic DNA viruses have never been fully addressed. Morphological, genetic and molecular data were used to test if all four cytoplasmic virus families (Ascoviridae, Iridoviridae, Asfarviridae, and Poxvirirdae) evolved from nuclear replicating baculoviruses and how the four virus groups are related. Molecular phylogenetic analyses using DNA polymerase predicted that cytoplasmic DNA viruses might have evolved from nuclear replicating baculoviruses, and that poxviruses and asfarviruses share a common ancestor with iridoviruses. These three cytoplasmic viruses again shared a common ancestor with ascoviruses. Morphological and genetic data predicted the same evolutionary trend as molecular data predicted. A genome sequence comparison showed that ascoviruses have more baculovirus protein homologues than do iridoviruses, which suggested that ascoviruses have evolved from baculoviruses and iridoviruses evolved from ascoviruses. Poxviruses showed genetic and morphological similarity to other cytoplamic viruses, such as ascoviruses, suggesting it has undergone reticulate evolution via hybridization, recombination and lateral gene transfer with other viruses. Within the ascovirus family, we tested if molecular phylogenetic analyses agree with biological inference; that is, ascovirus had an evolutionary trend of increasing genome size, expanding host range and widening tissue tropism for these viruses. Both molecular and biological data predicted this evolutionary trend. The phylogenetic relationship among the four species of ascovirus was predicted to be that TnAV-2 and HvAV-3 shared a common ancestor with SfAV-1 and the three virus species again shared a common ancestor with DpAV-4.

  15. Teaching Tree-Thinking to Undergraduate Biology Students

    OpenAIRE

    Meisel, Richard P.

    2010-01-01

    Evolution is the unifying principle of all biology, and understanding how evolutionary relationships are represented is critical for a complete understanding of evolution. Phylogenetic trees are the most conventional tool for displaying evolutionary relationships, and “tree-thinking” has been coined as a term to describe the ability to conceptualize evolutionary relationships. Students often lack tree-thinking skills, and developing those skills should be a priority of biology curricula. Many...

  16. Om religion og evolution

    DEFF Research Database (Denmark)

    Geertz, Armin W.

    kulturens kausale virkning på den menneskelige kognition og ikke mindst den hominine evolution. Ud fra, hvad vi ved om den menneskelige evolution, ses det, at den hominine evolution har en dybde, som sjældent medtænkes i teorier og hypoteser om den menneskelige evolution. Den menneskelige evolution er...

  17. The Evolution Model of Intelligent Matter

    Directory of Open Access Journals (Sweden)

    Bazaluk Oleg

    2014-03-01

    Full Text Available The article deals with the evolution model of reasonable matter (noogenesis, discovering the planetary and cosmic scale of the mind development. The author considers a historiography of this problem field, a contribution of scientific community to the development of basic provisions - noogenesis. According to the author, the evolution model of reasonable matter consists of three interdependent and mutually complementary models: 1. Models of continuous and nonlinear complication of structures of reasonable matter (neuro-evolution; 2. Models of continuous and nonlinear complication of types of interacting (or shown functions structures of the system of reasonable matter. 3. Models of continuous and nonlinear complication of the surroundings of reasonable matter (socio-cultural evolution. All these models include the author's understanding and corresponding arguments. In conclusion the author compares models of living and reasonable matter (biological evolution and noogenesis

  18. Experimental evolution in fungi: An untapped resource.

    Science.gov (United States)

    Fisher, Kaitlin J; Lang, Gregory I

    2016-09-01

    Historically, evolutionary biology has been considered an observational science. Examining populations and inferring evolutionary histories mold evolutionary theories. In contrast, laboratory evolution experiments make use of the amenability of traditional model organisms to study fundamental processes underlying evolution in real time in simple, but well-controlled, environments. With advances in high-throughput biology and next generation sequencing, it is now possible to propagate hundreds of parallel populations over thousands of generations and to quantify precisely the frequencies of various mutations over time. Experimental evolution combines the ability to simultaneously monitor replicate populations with the power to vary individual parameters to test specific evolutionary hypotheses, something that is impractical or infeasible in natural populations. Many labs are now conducting laboratory evolution experiments in nearly all model systems including viruses, bacteria, yeast, nematodes, and fruit flies. Among these systems, fungi occupy a unique niche: with a short generation time, small compact genomes, and sexual cycles, fungi are a particularly valuable and largely untapped resource for propelling future growth in the field of experimental evolution. Here, we describe the current state of fungal experimental evolution and why fungi are uniquely positioned to answer many of the outstanding questions in the field. We also review which fungal species are most well suited for experimental evolution. PMID:27375178

  19. Motilin and ghrelin gene experienced episodic evolution during primitive placental mammal evolution

    Institute of Scientific and Technical Information of China (English)

    IRWIN; M.; David

    2010-01-01

    Motilin and ghrelin,members of a structure-function-related hormone family,play important roles in gastrointestinal function,regulation of energy homeostasis and growth hormone secretion.We observed episodic evolution in both of their prehormone gene sequences during primitive placental mammal evolution,during which most of the nonsynonymous changes result in radical substitution.Of note,a functional obestatin hormone might have only originated after this episodic evolution event.Early in placental mammal evolution,a series of biology complexities evolved.At the same time the motilin and ghrelin prehormone genes,which play important roles in several of these processes,experienced episodic evolution with dramatic changes in their coding sequences.These observations suggest that some of the lineage-specific physiological adaptations are due to episodic evolution of the motilin and ghrelin genes.

  20. Evolution of genome architecture.

    Science.gov (United States)

    Koonin, Eugene V

    2009-02-01

    Charles Darwin believed that all traits of organisms have been honed to near perfection by natural selection. The empirical basis underlying Darwin's conclusions consisted of numerous observations made by him and other naturalists on the exquisite adaptations of animals and plants to their natural habitats and on the impressive results of artificial selection. Darwin fully appreciated the importance of heredity but was unaware of the nature and, in fact, the very existence of genomes. A century and a half after the publication of the "Origin", we have the opportunity to draw conclusions from the comparisons of hundreds of genome sequences from all walks of life. These comparisons suggest that the dominant mode of genome evolution is quite different from that of the phenotypic evolution. The genomes of vertebrates, those purported paragons of biological perfection, turned out to be veritable junkyards of selfish genetic elements where only a small fraction of the genetic material is dedicated to encoding biologically relevant information. In sharp contrast, genomes of microbes and viruses are incomparably more compact, with most of the genetic material assigned to distinct biological functions. However, even in these genomes, the specific genome organization (gene order) is poorly conserved. The results of comparative genomics lead to the conclusion that the genome architecture is not a straightforward result of continuous adaptation but rather is determined by the balance between the selection pressure, that is itself dependent on the effective population size and mutation rate, the level of recombination, and the activity of selfish elements. Although genes and, in many cases, multigene regions of genomes possess elaborate architectures that ensure regulation of expression, these arrangements are evolutionarily volatile and typically change substantially even on short evolutionary scales when gene sequences diverge minimally. Thus, the observed genome

  1. A slow rate of chromosome evolution unites squamate reptiles

    Czech Academy of Sciences Publication Activity Database

    Pokorná, Martina; Kratochvíl, L.; Giovannotti, M.; Trifonov, V. A.; Ferguson-Smith, M. A.; Caputo, V.; Olmo, E.; Rens, W.

    Cordoba : Universidad de Cordoba, 2012. 63-63. [International Colloquium on Animal Cytogenetics and Gene Mapping /20./. 25.04.2012-28.04.2012, Cordoba] Institutional support: RVO:67985904 Keywords : chromosome evolution Subject RIV: EB - Genetics ; Molecular Biology

  2. The balanced minimum evolution problem under uncertain data

    NARCIS (Netherlands)

    Catanzaro, Daniele; Labbe, Martine; Pesenti, Raffaele

    2013-01-01

    We investigate the Robust Deviation Balanced Minimum Evolution Problem (RDBMEP), a combinatorial optimization problem that arises in computational biology when the evolutionary distances from taxa are uncertain and varying inside intervals. By exploiting some fundamental properties of the objective

  3. Evolution of specialization and ecological character displacement: metabolic plasticity matters.

    NARCIS (Netherlands)

    C.J.M. Egas

    2005-01-01

    An important question in evolutionary biology, especially with respect to herbivorous arthropods, is the evolution of specialization. In a previous paper, the combined evolutionary dynamics of specialization and ecological character displacement was studied, focusing on the role of herbivore foragin

  4. Physics and Size in Biological Systems.

    Science.gov (United States)

    Barnes, George

    1989-01-01

    Described is the subject of biological scaling for physics teachers including examples and in-depth reading. Topics are elements of scaling, terminal velocities, Lilliputian and Brobdingnagian, brain evolution, dolphin echolocation, surface tension, gravity change, food and oxygen, and seeing. Ten references on physics and size, and ten questions…

  5. Professor Attitudes and Beliefs about Teaching Evolution

    Science.gov (United States)

    Barnes, Maryann Elizabeth

    Teaching evolution has been shown to be a challenge for faculty, in both K-12 and postsecondary education. Many of these challenges stem from perceived conflicts not only between religion and evolution, but also faculty beliefs about religion, it's compatibility with evolutionary theory, and it's proper role in classroom curriculum. Studies suggest that if educators engage with students' religious beliefs and identity, this may help students have positive attitudes towards evolution. The aim of this study was to reveal attitudes and beliefs professors have about addressing religion and providing religious scientist role models to students when teaching evolution. 15 semi-structured interviews of tenured biology professors were conducted at a large Midwestern universiy regarding their beliefs, experiences, and strategies teaching evolution and particularly, their willingness to address religion in a class section on evolution. Following a qualitative analysis of transcripts, professors did not agree on whether or not it is their job to help students accept evolution (although the majority said it is not), nor did they agree on a definition of "acceptance of evolution". Professors are willing to engage in students' religious beliefs, if this would help their students accept evolution. Finally, professors perceived many challenges to engaging students' religious beliefs in a science classroom such as the appropriateness of the material for a science class, large class sizes, and time constraints. Given the results of this study, the author concludes that instructors must come to a consensus about their goals as biology educators as well as what "acceptance of evolution" means, before they can realistically apply the engagement of student's religious beliefs and identity as an educational strategy.

  6. Groupware requirements evolution patterns

    NARCIS (Netherlands)

    Pumareja, Dulce Trinidad

    2013-01-01

    Requirements evolution is a generally known problem in software development. Requirements are known to change all throughout a system's lifecycle. Nevertheless, requirements evolution is a poorly understood phenomenon. Most studies on requirements evolution focus on changes to written specifications

  7. The Imperatives of Cosmic Biology

    CERN Document Server

    Gibson, Carl H

    2010-01-01

    The transformation of organic molecules into the simplest self-replicating living system,a microorganism, is accomplished from a unique event or rare events that occurred early in the Universe. The subsequent dispersal on cosmic scales and evolution of life is guaranteed, being determined by well-understood processes of physics and biology. Entire galaxies and clusters of galaxies can be considered as connected biospheres, with lateral gene transfers, as initially theorized by Joseph (2000), providing for genetic mixing and Darwinian evolution on a cosmic scale. Big bang cosmology modified by modern fluid mechanics suggests the beginning and wide intergalactic dispersal of life occurred immediately after the end of the plasma epoch when the gas of protogalaxies in clusters fragmented into clumps of planets. Stars are born from binary mergers of such planets within such clumps. When stars devour their surrounding planets to excess they explode, distributing necessary fertilizing chemicals created only in stars...

  8. Programmed Evolution for Optimization of Orthogonal Metabolic Output in Bacteria

    OpenAIRE

    Eckdahl, Todd T.; Campbell, A. Malcolm; Heyer, Laurie J.; Poet, Jeffrey L; Blauch, David N.; Snyder, Nicole L.; Atchley, Dustin T.; Baker, Erich J.; Brown, Micah; Brunner, Elizabeth C.; Callen, Sean A.; Campbell, Jesse S.; Carr, Caleb J.; Carr, David R.; Chadinha, Spencer A.

    2015-01-01

    Current use of microbes for metabolic engineering suffers from loss of metabolic output due to natural selection. Rather than combat the evolution of bacterial populations, we chose to embrace what makes biological engineering unique among engineering fields – evolving materials. We harnessed bacteria to compute solutions to the biological problem of metabolic pathway optimization. Our approach is called Programmed Evolution to capture two concepts. First, a population of cells is programmed ...

  9. Molecular biology: Self-sustaining chemistry

    Directory of Open Access Journals (Sweden)

    Wrede Paul

    2007-10-01

    Full Text Available Abstract Molecular biology is an established interdisciplinary field within biology that deals fundamentally with the function of any nucleic acid in the cellular context. The molecular biology section in Chemistry Central Journal focusses on the genetically determined chemistry and biochemistry occuring in the cell. How can thousands of chemical reactions interact smoothly to maintain the life of cells, even in a variable environment? How is this self-sustaining system achieved? These are questions that should be answered in the light of molecular biology and evolution, but with the application of biophysical, physico-chemical, analytical and preparative technologies. As the Section Editor for the molecular biology section in Chemistry Central Journal, I hope to receive manuscripts that present new approaches aimed at better answering and shedding light upon these fascinating questions related to the chemistry of livings cells.

  10. [Classification of organisms and structuralism in biology].

    Science.gov (United States)

    Vasil'eva, L I

    2001-01-01

    Structuralism in biology is the oldest trend oriented to the search for natural "laws of forms" comparable with laws of growth of crystal, was revived at the end of 20th century on the basis of structuralist thought in socio-humanitarian sciences. The development of principal ideas of the linguistic structuralism in some aspects is similar to that of biological systematics, especially concerning the relationships between "system" and "evolution". However, apart from this general similarity, biological structuralism is strongly focused on familiar problems of the origin of diversity in nature. In their striving for the renovation of existing views, biological structuralists oppose the neo-darwinism emphasizing the existence of "law of forms", that are independent on heredity and genetic "determinism". The trend to develop so-called "rational taxonomy" is also characteristic of biological structuralism but this attempt failed being connected neither with Darwin's historicism nor with Plato's typology. PMID:11605547

  11. Biological effects of radiation

    International Nuclear Information System (INIS)

    This fourth chapter presents: cell structure and metabolism; radiation interaction with biological tissues; steps of the production of biological effect of radiation; radiosensitivity of tissues; classification of biological effects; reversibility, transmissivity and influence factors; pre-natal biological effects; biological effects in therapy and syndrome of acute irradiation

  12. Nudging Evolution?

    Directory of Open Access Journals (Sweden)

    Katharine N. Farrell

    2013-12-01

    Full Text Available This Special Feature, "Nudging Evolution? Critical Exploration of the Potential and Limitations of the Concept of Institutional Fit for the Study and Adaptive Management of Social-Ecological Systems," aims to contribute toward the development of social theory and social research methods for the study of social-ecological system dynamics. Our objective is to help strengthen the academic discourse concerning if, and if so, how, to what extent, and in what concrete ways the concept of institutional "fit" might play a role in helping to develop better understanding of the social components of interlinkages between the socioeconomic-cultural and ecological dynamics of social-ecological systems. Two clearly discernible patterns provide a map of this Special Feature: (1 One pattern is the authors' positions regarding the place and role of normativity within their studies and assessment of institutional fit. Some place this at the center of their studies, exploring phenomena endogenous to the process of defining what constitutes institutional fit, whereas others take the formation of norms as a phenomenon exogenous to their study. (2 Another pattern is the type of studies presented: critiques and elaborations of the theory, methods for judging qualities of fit, and/or applied case studies using the concept. As a body of work, these contributions highlight that self-understanding of social-ecological place, whether explicit or implicit, constitutes an important part of the study object, i.e., the role of institutions in social-ecological systems, and that this is, at the same time, a crucial point of reference for the scholar wishing to evaluate what constitutes institutional fit and how it might be brought into being.

  13. Biological extinction in earth history

    Science.gov (United States)

    Raup, D. M.

    1986-01-01

    Virtually all plant and animal species that have ever lived on the earth are extinct. For this reason alone, extinction must play an important role in the evolution of life. The five largest mass extinctions of the past 600 million years are of greatest interest, but there is also a spectrum of smaller events, many of which indicate biological systems in profound stress. Extinction may be episodic at all scales, with relatively long periods of stability alternating with short-lived extinction events. Most extinction episodes are biologically selective, and further analysis of the victims and survivors offers the greatest chance of deducing the proximal causes of extinction. A drop in sea level and climatic change are most frequently invoked to explain mass extinctions, but new theories of collisions with extraterrestrial bodies are gaining favor. Extinction may be constructive in a Darwinian sense or it may only perturb the system by eliminating those organisms that happen to be susceptible to geologically rare stresses.

  14. Biological Extinction in Earth History

    Science.gov (United States)

    Raup, David M.

    1986-03-01

    Virtually all plant and animal species that have ever lived on the earth are extinct. For this reason alone, extinction must play an important role in the evolution of life. The five largest mass extinctions of the past 600 million years are of greatest interest, but there is also a spectrum of smaller events, many of which indicate biological systems in profound stress. Extinction may be episodic at all scales, with relatively long periods of stability alternating with short-lived extinction events. Most extinction episodes are biologically selective, and further analysis of the victims and survivors offers the greatest chance of deducing the proximal causes of extinction. A drop in sea level and climatic change are most frequently invoked to explain mass extinctions, but new theories of collisions with extraterrestrial bodies are gaining favor. Extinction may be constructive in a Darwinian sense or it may only perturb the system by eliminating those organisms that happen to be susceptible to geologically rare stresses.

  15. The Evolution of Textbook Misconceptions about Darwin

    Science.gov (United States)

    Rees, Paul A.

    2007-01-01

    Textbooks for GCE Advanced Level Biology have provided over-simplified and inaccurate accounts of Charles Darwin's contribution to the study of evolution over a period of many decades. They have credited him with field skills and insight that he did not possess, and repeated several historical inaccuracies. Darwin's strength was as a synthesiser…

  16. Evolution of parasitism in kinetoplastid flagellates

    Czech Academy of Sciences Publication Activity Database

    Lukeš, Julius; Skalický, Tomáš; Týč, Jiří; Votýpka, Jan; Yurchenko, Vyacheslav

    2014-01-01

    Roč. 195, č. 2 (2014), s. 115-122. ISSN 0166-6851 R&D Projects: GA MŠk(CZ) EE2.3.30.0032 Institutional support: RVO:60077344 Keywords : Evolution * Phylogeny * Vectors * Diversity * Parasitism * Trypanosome Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.787, year: 2014

  17. Evolution: Don't Debate, Educate.

    Science.gov (United States)

    Bybee, Rodger W.

    2000-01-01

    Discusses controversy over the teaching of biological evolution and other scientific ideas such as Big Bang theory. Recommends that teachers avoid debating creationists, help students develop a greater understanding and appreciation for science as a way of explaining the natural world, and emphasize inquiry and the nature of science. (Contains 19…

  18. The evolution of innate lymphoid cells.

    Science.gov (United States)

    Vivier, Eric; van de Pavert, Serge A; Cooper, Max D; Belz, Gabrielle T

    2016-06-21

    Innate lymphoid cells (ILCs) are the most recently discovered group of immune cells. Understanding their biology poses many challenges. We discuss here the current knowledge on the appearance of ILC subsets during evolution and propose how the connection between ILCs and T cells contributes to the robustness of immunity and hence to the fitness of the hosts. PMID:27328009

  19. The evolution and diversity of kinetoplastid flagellates

    Czech Academy of Sciences Publication Activity Database

    Simpson, A. G. B.; Stevens, J. R.; Lukeš, Julius

    2006-01-01

    Roč. 22, č. 4 (2006), s. 168-174. ISSN 1471-4922 R&D Projects: GA AV ČR 1QS600220554 Institutional research plan: CEZ:AV0Z60220518 Keywords : evolution * kinetoplastids * diversity Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.907, year: 2006

  20. Statistical Analysis of Hominoid Molecular Evolution

    OpenAIRE

    Barry, Daniel; Hartigan, J. A.

    1987-01-01

    The core data of molecular biology consists of DNA sequences. We will show how DNA sequences may be used to infer the evolution of the primates, human, chimpanzee, ape, orangutan and gibbon. The underlying probability models are taken to be Markov processes on trees. Some dependencies along the sequence due to the genetic code are also considered.

  1. The Theory of Evolution: An Educational Perspective.

    Science.gov (United States)

    Johnson, William L.; Johnson, Annabel M.

    The article's thesis is that evolution's intellectual foundations have been steadily eroding, and that few new findings in embryology, taxonomy, fossil remains, and molecular biology are bringing us very near to a formal, logical disproof of Darwinian claims. The paper begins by discussing the evidence of a prehistoric world, then they discuss…

  2. Radiation and the evolution of life

    International Nuclear Information System (INIS)

    A general review is presented of the nature of various forms of radiation; radiant energy which reaches the earth from the sun; the role of this energy in prebiotic chemical evolution; current ideas on the origin of life; the dependence of living organisms upon radiant energy; the mechanisms responsible for the evolution of life, from the viewpoint of modern genetics and molecular biology; the biological consequences of alterations in the genetic material; and the role of ionizing radiation in production of genetic changes and in evolution. In the final analysis, the biosynthetic processes of life are driven by radiant energy from the sun. This overview is necessarily focussed on the infrared, visible and ultraviolet regions of the solar output spectrum since these particular radiations are responsible for most of the radiant energy that reaches the earth's surface. Ionizing radiation appears to have played at best a minor role in biological evolution. Small increments in the amounts of ionizing radiation are therefore unlikely to have a significant effect on life or its evolution. (auth)

  3. Getting to Darwin: Obstacles to Accepting Evolution by Natural Selection

    Science.gov (United States)

    Thagard, Paul; Findlay, Scott

    2010-01-01

    Darwin's theory of evolution by natural selection is central to modern biology, but is resisted by many people. This paper discusses the major psychological obstacles to accepting Darwin's theory. Cognitive obstacles to adopting evolution by natural selection include conceptual difficulties, methodological issues, and coherence problems that…

  4. Teaching Evolution: A Heuristic Study of Personal and Cultural Dissonance

    Science.gov (United States)

    Grimes, Larry G.

    2012-01-01

    Darwinian evolution is a robustly supported scientific theory. Yet creationists continue to challenge its teaching in American public schools. Biology teachers in all 50 states are responsible for teaching science content standards that include evolution. As products of their backgrounds and affiliations teachers bring personal attitudes and…

  5. Qualitative Differences between Naive and Scientific Theories of Evolution

    Science.gov (United States)

    Shtulman, Andrew

    2006-01-01

    Philosophers of biology have long argued that Darwin's theory of evolution was qualitatively different from all earlier theories of evolution. Whereas Darwin's predecessors and contemporaries explained adaptation as the transformation of a species' ''essence,'' Darwin explained adaptation as the selective propagation of randomly occurring…

  6. Teaching Evolution: From SMART Objectives to Threshold Experience

    Science.gov (United States)

    Wolf, Alexander; Akkaraju, Shylaja

    2014-01-01

    Despite the centrality of evolution to the study of biology, the pedagogical methods employed to teach the subject are often instructor-centered and rarely embedded in every topic throughout the curriculum. In addition, students' prior beliefs about evolution are often dismissed rather than incorporated into the classroom. In this article we…

  7. "Reinventing Life": Introductory Biology for a Rapidly Evolving World

    Science.gov (United States)

    Coker, Jeffrey Scott

    2009-01-01

    Evolutionary concepts are essential for a scientific understanding of most issues surrounding modern medicine, agriculture, biotechnology, and the environment. If the mantra for biology education in the 20th century was, "Nothing in biology makes sense except in the light of evolution," the mantra for the 21st century must be, "Nothing in biology…

  8. Fluctuation theorem for the mutation process in in vitro evolution

    International Nuclear Information System (INIS)

    A proposition based on the fluctuation theorem in thermodynamics is formulated to quantitatively describe molecular evolution processes in biology. Although we cannot give full proof of its generality, we demonstrate via computer simulation its applicability in an example of DNA in vitro evolution. According to this theorem, the evolution process is a series of exponentially rare fluctuations fixed by the force of natural selection. (general)

  9. Co-evolution of primordial membranes and membrane proteins

    OpenAIRE

    Mulkidjanian, Armen Y.; Galperin, Michael Y; Koonin, Eugene V

    2009-01-01

    Studies of the past several decades have provided major insights into the structural organization of biological membranes and mechanisms of many membrane molecular machines. However, the origin(s) of the membrane(s) and membrane proteins remain enigmatic. We discuss different concepts of the origin and early evolution of membranes, with a focus on the evolution of the (im)permeability to charged molecules, such as proteins and nucleic acids, and small ions. Reconstruction of the evolution of ...

  10. Adaptive molecular convergence: Molecular evolution versus molecular phylogenetics

    OpenAIRE

    Castoe, Todd A.; de Koning, A. P. Jason; Pollock, David D.

    2010-01-01

    Definitive identification of convergent evolution, the acquisition of the same biological trait in unrelated lineages, provides one of the most compelling sources of evidence for natural selection. Although numerous examples of convergent morphological evolution are well known (such as the independent development of wings in birds and mammals), cases of convergent evolution at the molecular-genetic level appear to be quite rare. We recently discovered a remarkable case of convergent molecular...

  11. Bacterial Evolution and the Bak-Sneppen Model

    Science.gov (United States)

    Bose, Indrani; Chaudhuri, Indranath

    Recently, Lenski et al.1-3 have carried out several experiments on bacterial evolution. Their findings support the theory of punctuated equilibrium in biological evolution. They have further quantified the relative contributions of adaptation, chance and history to bacterial evolution. In this paper, we show that a modified M-trait Bak-Sneppen model can explain many of the experimental results in a qualitative manner.

  12. Bacterial evolution and the Bak-Sneppen model

    OpenAIRE

    Bose, Indrani; Chaudhuri, Indranath

    2001-01-01

    Recently, Lenski et al \\cite{Elena,Lenski,Travisano} have carried out several experiments on bacterial evolution. Their findings support the theory of punctuated equilibrium in biological evolution. They have further quantified the relative contributions of adaptation, chance and history to bacterial evolution. In this Brief Report, we show that a modified M-trait Bak-Sneppen model can explain many of the experimental results in a qualitative manner.

  13. Observing bacteria through the lens of social evolution

    OpenAIRE

    Nadell, Carey D.; Bassler, Bonnie L; Levin, Simon A.

    2008-01-01

    Explaining the evolution of cooperative behavior is a long-standing problem for which much theory has been developed. A recent paper in BMC Biology tests central elements of this theory by manipulating a simple bacterial experimental system. This approach is useful for assessing the principles of social evolution, but we argue that more effort must be invested in the inverse problem: using social evolution theory to understand the lives of bacteria.

  14. Positioning Genomics in Biology Education: Content Mapping of Undergraduate Biology Textbooks

    Directory of Open Access Journals (Sweden)

    Naomi L. B. Wernick

    2014-07-01

    Full Text Available Biological thought increasingly recognizes the centrality of the genome in constituting and regulating processes ranging from cellular systems to ecology and evolution. In this paper, we ask whether genomics is similarly positioned as a core concept in the instructional sequence for undergraduate biology. Using quantitative methods, we analyzed the order in which core biological concepts were introduced in textbooks for first-year general and human biology. Statistical analysis was performed using self-organizing map algorithms and conventional methods to identify clusters of terms and their relative position in the books. General biology textbooks for both majors and nonmajors introduced genome-related content after text related to cell biology and biological chemistry, but before content describing higher-order biological processes. However, human biology textbooks most often introduced genomic content near the end of the books. These results suggest that genomics is not yet positioned as a core concept in commonly used textbooks for first-year biology and raises questions about whether such textbooks, or courses based on the outline of these textbooks, provide an appropriate foundation for understanding contemporary biological science.

  15. Cultural evolution: implications for understanding the human language faculty and its evolution

    OpenAIRE

    Smith, Kenny; Kirby, Simon

    2008-01-01

    Human language is unique among the communication systems of the natural world: it is socially learned and, as a consequence of its recursively compositional structure, offers open-ended communicative potential. The structure of this communication system can be explained as a consequence of the evolution of the human biological capacity for language or the cultural evolution of language itself. We argue, supported by a formal model, that an explanatory account that involves some role for cultu...

  16. Modelling language evolution: Examples and predictions

    Science.gov (United States)

    Gong, Tao; Shuai, Lan; Zhang, Menghan

    2014-06-01

    We survey recent computer modelling research of language evolution, focusing on a rule-based model simulating the lexicon-syntax coevolution and an equation-based model quantifying the language competition dynamics. We discuss four predictions of these models: (a) correlation between domain-general abilities (e.g. sequential learning) and language-specific mechanisms (e.g. word order processing); (b) coevolution of language and relevant competences (e.g. joint attention); (c) effects of cultural transmission and social structure on linguistic understandability; and (d) commonalities between linguistic, biological, and physical phenomena. All these contribute significantly to our understanding of the evolutions of language structures, individual learning mechanisms, and relevant biological and socio-cultural factors. We conclude the survey by highlighting three future directions of modelling studies of language evolution: (a) adopting experimental approaches for model evaluation; (b) consolidating empirical foundations of models; and (c) multi-disciplinary collaboration among modelling, linguistics, and other relevant disciplines.

  17. The middle way of evolution.

    Science.gov (United States)

    Hunt, Tam

    2012-09-01

    THIS ESSAY PROVIDES A CRITICAL REVIEW OF TWO RECENT BOOKS ON EVOLUTION: Richard Dawkins' The Greatest Show on Earth, and Jerry Coyne's Why Evolution is True, as well as a critique of mainstream evolutionary theory and of natural selection. I also suggest a generalization of sexual selection theory that acknowledges mind as pervasive in nature. Natural selection, as the primary theory of how biological change occurs, must be carefully framed to avoid the long-standing "tautology problem" and must also be modified to more explicitly include the role of mind in evolution. A propensity approach to natural selection, in which "expected fitness" is utilized rather than "fitness," can save natural selection from tautology. But to be a productive theory, natural selection theory should be placed alongside sexual selection - which is explicitly agentic/intentional - as a twin force, but also placed alongside purely endogenous factors such as genetic drift. This framing is contrary to the normal convention that often groups all of these factors under the rubric of "natural selection." I suggest some approaches for improving modern evolutionary theory, including a "generalized sexual selection," a panpsychist extension of Darwin's theory of sexual selection that explicitly recognizes the role of mind at all levels of nature and which may play the part of a general theory of evolution better than natural selection theory. PMID:23181154

  18. Evolution in Stage-Structured Populations

    Science.gov (United States)

    Barfield, Michael; Holt, Robert D.; Gomulkiewicz, Richard

    2016-01-01

    For many organisms, stage is a better predictor of demographic rates than age. Yet no general theoretical framework exists for understanding or predicting evolution in stage-structured populations. Here, we provide a general modeling approach that can be used to predict evolution and demography of stage-structured populations. This advances our ability to understand evolution in stage-structured populations to a level previously available only for populations structured by age. We use this framework to provide the first rigorous proof that Lande’s theorem, which relates adaptive evolution to population growth, applies to stage-classified populations, assuming only normality and that evolution is slow relative to population dynamics. We extend this theorem to allow for different means or variances among stages. Our next major result is the formulation of Price’s theorem, a fundamental law of evolution, for stage-structured populations. In addition, we use data from Trillium grandiflorum to demonstrate how our models can be applied to a real-world population and thereby show their practical potential to generate accurate projections of evolutionary and population dynamics. Finally, we use our framework to compare rates of evolution in age- versus stage-structured populations, which shows how our methods can yield biological insights about evolution in stage-structured populations. PMID:21460563

  19. Computational Modeling of Biological Systems From Molecules to Pathways

    CERN Document Server

    2012-01-01

    Computational modeling is emerging as a powerful new approach for studying and manipulating biological systems. Many diverse methods have been developed to model, visualize, and rationally alter these systems at various length scales, from atomic resolution to the level of cellular pathways. Processes taking place at larger time and length scales, such as molecular evolution, have also greatly benefited from new breeds of computational approaches. Computational Modeling of Biological Systems: From Molecules to Pathways provides an overview of established computational methods for the modeling of biologically and medically relevant systems. It is suitable for researchers and professionals working in the fields of biophysics, computational biology, systems biology, and molecular medicine.

  20. Endosymbiosis and Eukaryotic Cell Evolution.

    Science.gov (United States)

    Archibald, John M

    2015-10-01

    Understanding the evolution of eukaryotic cellular complexity is one of the grand challenges of modern biology. It has now been firmly established that mitochondria and plastids, the classical membrane-bound organelles of eukaryotic cells, evolved from bacteria by endosymbiosis. In the case of mitochondria, evidence points very clearly to an endosymbiont of α-proteobacterial ancestry. The precise nature of the host cell that partnered with this endosymbiont is, however, very much an open question. And while the host for the cyanobacterial progenitor of the plastid was undoubtedly a fully-fledged eukaryote, how - and how often - plastids moved from one eukaryote to another during algal diversification is vigorously debated. In this article I frame modern views on endosymbiotic theory in a historical context, highlighting the transformative role DNA sequencing played in solving early problems in eukaryotic cell evolution, and posing key unanswered questions emerging from the age of comparative genomics. PMID:26439354

  1. Molecular biology of Homo sapiens: Abstracts of papers presented at the 51st Cold Spring Harbor symposium on quantitative biology

    International Nuclear Information System (INIS)

    This volume contains abstracts of papers presented at the 51st Cold Springs Harbor Symposium on Quantitative Biology. The topic for this meeting was the ''Molecular Biology of Homo sapiens.'' Sessions were entitled Human Gene Map, Human Cancer Genes, Genetic Diagnosis, Human Evolution, Drugs Made Off Human Genes, Receptors, and Gene Therapy. (DT)

  2. Molecular biology of Homo sapiens: Abstracts of papers presented at the 51st Cold Spring Harbor symposium on quantitative biology

    Energy Technology Data Exchange (ETDEWEB)

    Watson, J.D.; Siniscalco, M.

    1986-01-01

    This volume contains abstracts of papers presented at the 51st Cold Springs Harbor Symposium on Quantitative Biology. The topic for this meeting was the ''Molecular Biology of Homo sapiens.'' Sessions were entitled Human Gene Map, Human Cancer Genes, Genetic Diagnosis, Human Evolution, Drugs Made Off Human Genes, Receptors, and Gene Therapy. (DT)

  3. The Criticism of Atheistic Evolution

    Directory of Open Access Journals (Sweden)

    Farah Ramin

    2010-04-01

    Full Text Available  With regard to close relation between evolution theory and religious knowledge, and its prodigious influence on arising new schools in philosophy this paper firstly considers the outcome of Darwin’s theologian theory in brief secondly it talks about recent controversies such as: ambiguity of Fitness concept, tautology and the usage of probability calculation in this theory,opposition of the second law of thermodynamics (Entropy, biological information in DNA, irreducible complexity, Fine-tuning of decisive nature constant and Anthropic Principle .

  4. Tuition vs. Intuition: Effects of Instruction on Naive Theories of Evolution

    Science.gov (United States)

    Shtulman, Andrew; Calabi, Prassede

    2013-01-01

    Recent research suggests that a major obstacle to evolution understanding is an essentialist view of the biological world. The present study investigated the effects of formal biology instruction on such misconceptions. Participants (N = 291) completed an assessment of their understanding of six aspects of evolution (variation, inheritance,…

  5. Thinking Evolutionarily: Evolution Education across the Life Sciences--Summary of a Convocation

    Science.gov (United States)

    Olson, Steve

    2012-01-01

    Evolution is the central unifying theme of biology. Yet today, more than a century and a half after Charles Darwin proposed the idea of evolution through natural selection, the topic is often relegated to a handful of chapters in textbooks and a few class sessions in introductory biology courses, if covered at all. In recent years, a movement has…

  6. The evolution of nitrogen cycling

    Science.gov (United States)

    Mancinelli, Rocco L.; Mckay, Christopher P.

    1988-01-01

    The energetics of nitrogen transformation reactions and the evolution of nitrogen cycling are examined. It is suggested that meteor impact-produced fixed nitrogen could have caused the entire reservoir of the earth's N2 to convert into fixed nitrogen at the end of accretion. The abiotic fixation rate on the early earth by lightning is estimated at about 1-3 X 10 to the 16th molecules of NO/J. It is found that biological nitrogen fixation may have evolved after the development of an aerobic atmosphere. It is shown that HNO could eventually become NO2(-) and NO3(-) after reaching the earth's surface. It is concluded that the evolutionary sequence for the biological transformation of nitrogen compounds is ammonification - denitrification - nitrification - nitrogen fixation.

  7. The evolution of complex life

    Science.gov (United States)

    Billingham, J.

    1985-01-01

    The emergence of complex living organisms in the context of evolutionary biology, planetary environments, and space events is investigated. The application of data on biological evolution, climatology, and the chemical and physical environments of the earth's surface, to explain the development of extraterrestrial life is described and an example is provided. The possibility of extraplanetary disturbances such as, meteorite and comet bombardments, and supernova explosions, causing the elimination of preexisting life and allowing advanced life development is analyzed. The possible existence of different life cycles (genetic and reproductive strategies) on other planets is studied. The GAIA hypothesis (Lovelock, 1979) which states living things modify the global environment to their own advantage is examined. The improved identification of habitable planetary environments and the possible existence of a form of extraterrestrial intelligent life is discussed.

  8. Earth's earliest biosphere: Its origin and evolution

    International Nuclear Information System (INIS)

    Some of the subjects discussed are related to the early biogeologic history, the nature of the earth prior to the oldest known rock record, the early earth and the Archean rock record, the prebiotic organic syntheses and the origin of life, Precambrian organic geochemistry, the biochemical evolution of anaerobic energy conversion, the isotopic inferences of ancient biochemistries, Archean stromatolites providing evidence of the earth's earliest benthos, Archean microfossils, the geologic evolution of the Archean-Early Proterozoic earth, and the environmental evolution of the Archean-Early Proterozoic earth. Other topics examined are concerned with geochemical evidence bearing on the origin of aerobiosis, biological and biochemical effects of the development of an aerobic environment, Early Proterozoic microfossils, the evolution of earth's earliest ecosystems, and geographic and geologic data for processed rock samples. Attention is given to a processing procedure for abiotic samples and calculation of model atmospheric compositions, and procedures of organic geochemical analysis

  9. Evolution from Cellular to Social Scales

    CERN Document Server

    Skjeltorp, Arne T

    2008-01-01

    Evolution is a critical challenge for many areas of science, technology and development of society. The book reviews general evolutionary facts such as origin of life and evolution of the genome and clues to evolution through simple systems. Emerging areas of science such as "systems biology" and "bio-complexity" are founded on the idea that phenomena need to be understood in the context of highly interactive processes operating at different levels and on different scales. This is where physics meets complexity in nature, and where we must begin to learn about complexity if we are to understand it. Similarly, there is an increasingly urgent need to understand and predict the evolutionary behavior of highly interacting man-made systems, in areas such as communications and transport, which permeate the modern world. The same applies to the evolution of human networks such as social, political and financial systems, where technology has tended to vastly increase both the complexity and speed of interaction, whic...

  10. Evolution of theological views on evolution

    OpenAIRE

    Hałaczek, Bernard

    1997-01-01

    Biology-oriented theology and philosophy-oriented biology have been a matter of controversy in the studies of human origins. This controversy terminates at the point when they both recognise their peculiarity: biology is concerned with the “how” man came into existence and theology with “what” of the existence o f man.

  11. Systems biology and mechanics of growth.

    Science.gov (United States)

    Eskandari, Mona; Kuhl, Ellen

    2015-01-01

    In contrast to inert systems, living biological systems have the advantage to adapt to their environment through growth and evolution. This transfiguration is evident during embryonic development, when the predisposed need to grow allows form to follow function. Alterations in the equilibrium state of biological systems breed disease and mutation in response to environmental triggers. The need to characterize the growth of biological systems to better understand these phenomena has motivated the continuum theory of growth and stimulated the development of computational tools in systems biology. Biological growth in development and disease is increasingly studied using the framework of morphoelasticity. Here, we demonstrate the potential for morphoelastic simulations through examples of volume, area, and length growth, inspired by tumor expansion, chronic bronchitis, brain development, intestine formation, plant shape, and myopia. We review the systems biology of living systems in light of biochemical and optical stimuli and classify different types of growth to facilitate the design of growth models for various biological systems within this generic framework. Exploring the systems biology of growth introduces a new venue to control and manipulate embryonic development, disease progression, and clinical intervention. PMID:26352286

  12. A first attempt to bring computational biology into advanced high school biology classrooms.

    Directory of Open Access Journals (Sweden)

    Suzanne Renick Gallagher

    2011-10-01

    Full Text Available Computer science has become ubiquitous in many areas of biological research, yet most high school and even college students are unaware of this. As a result, many college biology majors graduate without adequate computational skills for contemporary fields of biology. The absence of a computational element in secondary school biology classrooms is of growing concern to the computational biology community and biology teachers who would like to acquaint their students with updated approaches in the discipline. We present a first attempt to correct this absence by introducing a computational biology element to teach genetic evolution into advanced biology classes in two local high schools. Our primary goal was to show students how computation is used in biology and why a basic understanding of computation is necessary for research in many fields of biology. This curriculum is intended to be taught by a computational biologist who has worked with a high school advanced biology teacher to adapt the unit for his/her classroom, but a motivated high school teacher comfortable with mathematics and computing may be able to teach this alone. In this paper, we present our curriculum, which takes into consideration the constraints of the required curriculum, and discuss our experiences teaching it. We describe the successes and challenges we encountered while bringing this unit to high school students, discuss how we addressed these challenges, and make suggestions for future versions of this curriculum.We believe that our curriculum can be a valuable seed for further development of computational activities aimed at high school biology students. Further, our experiences may be of value to others teaching computational biology at this level. Our curriculum can be obtained at http://ecsite.cs.colorado.edu/?page_id=149#biology or by contacting the authors.

  13. Biological conversion system

    Science.gov (United States)

    Scott, C.D.

    A system for bioconversion of organic material comprises a primary bioreactor column wherein a biological active agent (zymomonas mobilis) converts the organic material (sugar) to a product (alcohol), a rejuvenator column wherein the biological activity of said biological active agent is enhanced, and means for circulating said biological active agent between said primary bioreactor column and said rejuvenator column.

  14. Synthetic biology: insights into biological computation.

    Science.gov (United States)

    Manzoni, Romilde; Urrios, Arturo; Velazquez-Garcia, Silvia; de Nadal, Eulàlia; Posas, Francesc

    2016-04-18

    Organisms have evolved a broad array of complex signaling mechanisms that allow them to survive in a wide range of environmental conditions. They are able to sense external inputs and produce an output response by computing the information. Synthetic biology attempts to rationally engineer biological systems in order to perform desired functions. Our increasing understanding of biological systems guides this rational design, while the huge background in electronics for building circuits defines the methodology. In this context, biocomputation is the branch of synthetic biology aimed at implementing artificial computational devices using engineered biological motifs as building blocks. Biocomputational devices are defined as biological systems that are able to integrate inputs and return outputs following pre-determined rules. Over the last decade the number of available synthetic engineered devices has increased exponentially; simple and complex circuits have been built in bacteria, yeast and mammalian cells. These devices can manage and store information, take decisions based on past and present inputs, and even convert a transient signal into a sustained response. The field is experiencing a fast growth and every day it is easier to implement more complex biological functions. This is mainly due to advances in in vitro DNA synthesis, new genome editing tools, novel molecular cloning techniques, continuously growing part libraries as well as other technological advances. This allows that digital computation can now be engineered and implemented in biological systems. Simple logic gates can be implemented and connected to perform novel desired functions or to better understand and redesign biological processes. Synthetic biological digital circuits could lead to new therapeutic approaches, as well as new and efficient ways to produce complex molecules such as antibiotics, bioplastics or biofuels. Biological computation not only provides possible biomedical and

  15. Developmental systems biology flourishing on new technologies

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Organism development is a systems level process. It has benefited greatly from the recent technological advances in the field of systems biology. DNA microarray, phenome, interactome and transcriptome mapping, the new generation of deep sequencing technologies,and faster and better computational and modeling approaches have opened new frontiers for both systems biologists and developmental biologists to reexamine the old developmental biology questions, such as pattern formation, and to tackle new problems, such as stem cell reprogramming. As showcased in the International Developmental Systems Biology Symposium organized by Chinese Academy of Sciences, developmental systems biology is flourishing in many perspectives, from the evolution of developmental systems, to the underlying genetic and molecular pathways and networks, to the genomic, epigenomic and noncoding levels, to the computational analysis and modeling. We believe that the field will continue to reap rewards into the future with these new approaches.

  16. Developmental systems biology flourishing on new technologies.

    Science.gov (United States)

    Han, Jing-Dong J; Liu, Yi; Xue, Huiling; Xia, Kai; Yu, Hong; Zhu, Shanshan; Chen, Zhang; Zhang, Wei; Huang, Zheng; Jin, Chunyu; Xian, Bo; Li, Jing; Hou, Lei; Han, Yixing; Niu, Chaoqun; Alcon, Timothy C

    2008-10-01

    Organism development is a systems level process. It has benefited greatly from the recent technological advances in the field of systems biology. DNA microarray, phenome, interactome and transcriptome mapping, the new generation of deep sequencing technologies, and faster and better computational and modeling approaches have opened new frontiers for both systems biologists and developmental biologists to reexamine the old developmental biology questions, such as pattern formation, and to tackle new problems, such as stem cell reprogramming. As showcased in the International Developmental Systems Biology Symposium organized by Chinese Academy of Sciences, developmental systems biology is flourishing in many perspectives, from the evolution of developmental systems, to the underlying genetic and molecular pathways and networks, to the genomic, epigenomic and noncoding levels, to the computational analysis and modeling. We believe that the field will continue to reap rewards into the future with these new approaches. PMID:18937914

  17. Teaching and Learning Evolution: Testing the Principles of a Constructivist Approach through Action Research

    Science.gov (United States)

    Oliver, Mary

    2011-01-01

    A tenth grade class in an international school studied evolution for four weeks as part of the study of Biology. A diagnostic test was used to determine the main misconceptions students have as they come to the study of evolution. This was followed by a series of explorations of different conceptual models to account for evolution, structured…

  18. Conceptual Ecology of the Evolution Acceptance among Greek Education Students: Knowledge, Religious Practices and Social Influences

    Science.gov (United States)

    Athanasiou, Kyriacos; Papadopoulou, Penelope

    2012-01-01

    In this study, we explored some of the factors related to the acceptance of evolution theory among Greek university students training to be teachers in early childhood education, using conceptual ecology for biological evolution as a theoretical framework. We examined the acceptance of evolution theory and we also looked into the relationship…

  19. Mother Knows Best: Epigenetic Inheritance, Maternal Effects, and the Evolution of Human Intelligence

    Science.gov (United States)

    Bjorklund, David F.

    2006-01-01

    Contemporary evolution biology has recognized the role of development in evolution. Evolutionarily oriented psychologists have similarly recognized the role that behavioral plasticity, particularly early in development, may have had on the evolution of species, harking back to the ideas of Baldwin (the Baldwin effect). Epigenetic theories of…

  20. [Biological mutualism, concepts and models].

    Science.gov (United States)

    Perru, Olivier

    2011-01-01

    Mutualism is a biological association for a mutual benefit between two different species. In this paper, firstly, we examine the history and signification of mutualism in relation to symbiosis. Then, we consider the link between concepts and models of mutualism. Models of mutualism depend on different concepts we use: If mutualism is situated at populations' level, it will be expressed by Lotka-Volterra models, concerning exclusively populations' size. If mutualism is considered as a resources' exchange or a biological market increasing the fitness of these organisms, it will be described at an individual level by a cost-benefit model. Our analysis will be limited to the history and epistemology of Lotka-Volterra models and we hypothesize that these models are adapted at first to translate dynamic evolutions of mutualism. They render stability or variations of size and assume that there are clear distinctions and a state of equilibrium between populations of different species. Italian mathematician Vito Volterra demonstrated that biological associations consist in a constant relation between some species. In 1931 and 1935, Volterra described the general form of antagonistic or mutualistic biological associations by the same differential equations. We recognize that these equations have been more used to model competition or prey-predator interactions, but a simple sign change allows describing mutualism. The epistemological problem is the following: Volterra's equations help us to conceptualize a global phenomenon. However, mutualistic interactions may have stronger effects away from equilibrium and these effects may be better understood at individual level. We conclude that, between 1985 and 2000, some researchers carried on working and converting Lotka-Volterra models but this description appeared as insufficient. So, other researchers adopted an economical viewpoint, considering mutualism as a biological market. PMID:22288336

  1. The evolution of replicators.

    Science.gov (United States)

    Szathmáry, E

    2000-11-29

    Replicators of interest in chemistry, biology and culture are briefly surveyed from a conceptual point of view. Systems with limited heredity have only a limited evolutionary potential because the number of available types is too low. Chemical cycles, such as the formose reaction, are holistic replicators since replication is not based on the successive addition of modules. Replicator networks consisting of catalytic molecules (such as reflexively autocatalytic sets of proteins, or reproducing lipid vesicles) are hypothetical ensemble replicators, and their functioning rests on attractors of their dynamics. Ensemble replicators suffer from the paradox of specificity: while their abstract feasibility seems to require a high number of molecular types, the harmful effect of side reactions calls for a small system size. No satisfactory solution to this problem is known. Phenotypic replicators do not pass on their genotypes, only some aspects of the phenotype are transmitted. Phenotypic replicators with limited heredity include genetic membranes, prions and simple memetic systems. Memes in human culture are unlimited hereditary, phenotypic replicators, based on language. The typical path of evolution goes from limited to unlimited heredity, and from attractor-based to modular (digital) replicators. PMID:11127914

  2. AGENTS OF CHANGE: MODELING BIOCULTURAL EVOLUTION IN UPPER PLEISTOCENE WESTERN EURASIA

    OpenAIRE

    C. Michael Barton; JULIEN RIEL-SALVATORE

    2012-01-01

    The complex interactions between social learning and biological change are key to understanding the human species and its origins. Yet paleoanthropological models often focus only on the evolution of the human genome and physical characters, while behavior is treated as an epiphenomenon of biological evolution. We present the results of a series of experiments that use computational models, parametrized with new archaeological data, to simulate the complex dynamics of human biocultural evolut...

  3. Contributions of experimental protobiogenesis to the theory of evolution

    Science.gov (United States)

    Fox, S. W.

    1976-01-01

    Inferences from experiments in protobiogenesis are examined as a forward extension of the theory of evolutionary biology. A nondiscontinuous, intraconsistent theory of general evolution embracing both protobiology and biology is outlined. This overview emphasizes Darwinian selection in the later stages of evolution, and stereochemical molecular selection in some of its earlier stages. It incorporates the concept of limitation of the scope of evolution by internal constraints on variation, based on the argument that internally limiting constraints observed in experiments with molecules are operative in organisms, if chemical processes occur within biological processes and biological processes are assumed to be exponentializations of chemical processes. Major evolutionary events might have occurred by rapid self-assembly processes analogous to those observed in the formation of phase-separated microspheres from amorphous powder or supersaturated solutions.

  4. Computational Systems Chemical Biology

    OpenAIRE

    Oprea, Tudor I.; May, Elebeoba E.; Leitão, Andrei; Tropsha, Alexander

    2011-01-01

    There is a critical need for improving the level of chemistry awareness in systems biology. The data and information related to modulation of genes and proteins by small molecules continue to accumulate at the same time as simulation tools in systems biology and whole body physiologically-based pharmacokinetics (PBPK) continue to evolve. We called this emerging area at the interface between chemical biology and systems biology systems chemical biology, SCB (Oprea et al., 2007).

  5. Pictures of Synthetic Biology

    OpenAIRE

    Cserer, Amelie; Seiringer, Alexandra

    2009-01-01

    This article is concerned with the representation of Synthetic Biology in the media and by biotechnology experts. An analysis was made of German-language media articles published between 2004 and 2008, and interviews with biotechnology-experts at the Synthetic Biology conference SB 3.0 in Zurich 2007. The results have been reflected in terms of the definition of Synthetic Biology, applications of Synthetic Biology and the perspectives of opportunities and risks. In the media, Synthetic Biolog...

  6. The fine details of evolution.

    Science.gov (United States)

    Laskowski, Roman A; Thornton, Janet M; Sternberg, Michael J E

    2009-08-01

    Charles Darwin's theory of evolution was based on studies of biology at the species level. In the time since his death, studies at the molecular level have confirmed his ideas about the kinship of all life on Earth and have provided a wealth of detail about the evolutionary relationships between different species and a deeper understanding of the finer workings of natural selection. We now have a wealth of data, including the genome sequences of a wide range of organisms, an even larger number of protein sequences, a significant knowledge of the three-dimensional structures of proteins, DNA and other biological molecules, and a huge body of information about the operation of these molecules as systems in the molecular machinery of all living things. This issue of Biochemical Society Transactions contains papers from oral presentations given at a Biochemical Society Focused Meeting to commemorate the 200th Anniversary of Charles Darwin's birth, held on 26-27 January 2009 at the Wellcome Trust Conference Centre, Cambridge. The talks reported on some of the insights into evolution which have been obtained from the study of protein sequences, structures and systems. PMID:19614583

  7. The Evolution of Extracellular Matrix

    Science.gov (United States)

    Özbek, Suat; Balasubramanian, Prakash G.; Chiquet-Ehrismann, Ruth; Tucker, Richard P.

    2010-01-01

    We present a perspective on the molecular evolution of the extracellular matrix (ECM) in metazoa that draws on research publications and data from sequenced genomes and expressed sequence tag libraries. ECM components do not function in isolation, and the biological ECM system or “adhesome” also depends on posttranslational processing enzymes, cell surface receptors, and extracellular proteases. We focus principally on the adhesome of internal tissues and discuss its origins at the dawn of the metazoa and the expansion of complexity that occurred in the chordate lineage. The analyses demonstrate very high conservation of a core adhesome that apparently evolved in a major wave of innovation in conjunction with the origin of metazoa. Integrin, CD36, and certain domains predate the metazoa, and some ECM-related proteins are identified in choanoflagellates as predicted sequences. Modern deuterostomes and vertebrates have many novelties and elaborations of ECM as a result of domain shuffling, domain innovations and gene family expansions. Knowledge of the evolution of metazoan ECM is important for understanding how it is built as a system, its roles in normal tissues and disease processes, and has relevance for tissue engineering, the development of artificial organs, and the goals of synthetic biology. PMID:21160071

  8. Evolution of species from Darwin theory: A simple model

    Science.gov (United States)

    Moret, M. A.; Pereira, H. B. B.; Monteiro, S. L.; Galeão, A. C.

    2012-04-01

    Evolution of species is a complex phenomenon. Some theoretical models take into account evolution of species, like the Bak-Sneppen model that obtain punctuated equilibrium from self-organized criticality and the Penna model for biological aging that consists in a bit-string model subjected to aging, reproduction and death. In this work we propose a simple model to study different scenarios used to simulate the evolution of species. This model is based on Darwin's ideas of evolution. The present findings show that punctuated equilibria and stasis seem to be obtained directly from the mutation, selection of parents and the genetic crossover, and are very close to the fossil data analysis.

  9. The 1st Symposium on Chemical Evolution and the Origin and Evolution of Life

    Science.gov (United States)

    Devincenzi, D. L. (Editor); Pleasant, L. G. (Editor)

    1982-01-01

    This symposium provided an opportunity for all NASA Exobiology principal investigators to present their most recent research in a scientific meeting forum. Papers were presented in the following exobiology areas: extraterrestrial chemistry primitive earth, information transfer, solar system exploration, planetary protection, geological record, and early biological evolution.

  10. Optimizing Nutrient Uptake in Biological Transport Networks

    Science.gov (United States)

    Ronellenfitsch, Henrik; Katifori, Eleni

    2013-03-01

    Many biological systems employ complex networks of vascular tubes to facilitate transport of solute nutrients, examples include the vascular system of plants (phloem), some fungi, and the slime-mold Physarum. It is believed that such networks are optimized through evolution for carrying out their designated task. We propose a set of hydrodynamic governing equations for solute transport in a complex network, and obtain the optimal network architecture for various classes of optimizing functionals. We finally discuss the topological properties and statistical mechanics of the resulting complex networks, and examine correspondence of the obtained networks to those found in actual biological systems.

  11. [History and biology: possible dialogues, necessary distances].

    Science.gov (United States)

    Duarte, Regina Horta

    2009-01-01

    Evolution has often been rejected as a theory incompatible with proper historical reflection. While there are undoubtedly insurmountable barriers between biology and the study of man and society, a rigorous analysis of Darwinist theory demonstrates epistemological areas of contact between history and evolutionary biology. The amazing temporal perspective shared by both areas of knowledge points to some bridges of communication, like the importance of the event and of creation processes, the rejection of teleology and the idea of progress, the complexity of events between chance and necessity, and the impossibility of making predictions. This affords an opportunity for a transdisciplinary approach at a moment of various contemporary challenges. PMID:21461513

  12. Six Classroom Exercises to Teach Natural Selection to Undergraduate Biology Students

    Science.gov (United States)

    Kalinowski, Steven T.; Leonard, Mary J.; Andrews, Tessa M.; Litt, Andrea R.

    2013-01-01

    Students in introductory biology courses frequently have misconceptions regarding natural selection. In this paper, we describe six activities that biology instructors can use to teach undergraduate students in introductory biology courses how natural selection causes evolution. These activities begin with a lesson introducing students to natural…

  13. Cosmic evolution, life and man

    International Nuclear Information System (INIS)

    Among the most basic problems confronting science are those regarding the origin of the universe, the origin of life and the origin of man. This general overview starts (1) with a brief introduction addressed primarily to the Cyril Ponnamperuma Memorial. Then, the thesis is presented that the appearance of life and intelligence on our planet can be understood as the result of a number of cosmic and biological evolutionary processes, including (2) the stellar thermonuclear synthesis of the biogenic elements other than hydrogen (C, N, O, P and S), their dispersal into space, and their combination into circumstellar and interstellar molecules. (3) The formation of the Solar System and the Earth-Moon System. (4) The role of comets and carbonaceous chondrites in contributing organic matter to the primitive Earth. (5) The prebiotics synthesis of amino acids, purines, pyrimidines, fatty acids, and other biochemical monomers. (6) The prebiotic condensation reactions leading to the synthesis of oligomers such as oligonucleotides and oligopeptides, with replicative and catalytic activities. (7) The synthesis of amphiphilic lipids, and their self-assembly into liposomes with bi-layered membranes. (8) The formation of protocellular structures. (9) The activation of protocells into a functioning Darwin's ancestral cell. (10) Early evolution of life. (11) The K-T boundary event and the disappearance of dinosaurs. (12) Evolution of hominids leading to Homo sapiens. (13) The rapid development of civilization. (14) The exploration of the Solar System. (15) Life beyond our planetary system. (16) Epilogue. Peace from cosmic evolution? (Abstract only)

  14. Evolution, communication, observation from biology to membrane computing and back

    OpenAIRE

    Cavaliere, Matteo

    2005-01-01

    La Computación Natural es una disciplina cuyo objetivo fundamental es la simulación e implementación de procesos dinámicos que se dan en la Naturaleza y que son susceptibles de ser interpretados como procedimientos de cálculo. ... height: 150%; font-family: 'Times New Roman','serif'; font-size: 12pt">La simulación que aborda la Computación Natural puede tener diversas interpretaciones a la hora de describir los nuevos modelos: que se utilice para el diseño de nuevos esquemas algorítmicos usan...

  15. The Free Energy Requirements of Biological Organisms; Implications for Evolution

    Science.gov (United States)

    Wolpert, David

    2016-04-01

    Recent advances in nonequilibrium statistical physics have provided unprecedented insight into the thermodynamics of dynamic processes. The author recently used these advances to extend Landauer's semi-formal reasoning concerning the thermodynamics of bit erasure, to derive the minimal free energy required to implement an arbitrary computation. Here I extend this analysis, deriving the minimal free energy required by an organism to run a given (stochastic) map $\\pi$ from its sensor inputs to its actuator outputs. I use this result to calculate the input-output map $\\pi$ of an organism that optimally trades off the free energy needed to run $\\pi$ with the phenotypic fitness that results from implementing $\\pi$. I end with general discussion of the limits imposed on the rate of the terrestrial biosphere's information processing by the flux of sunlight on the Earth.

  16. Mathematical modeling of the evolution of a simple biological system

    Digital Repository Service at National Institute of Oceanography (India)

    Gonsalves, M.J.B.D.; Neetu, S.; Krishnan, K.P.; Attri, K.; LokaBharathi, P.A.

    of nitrite. Within 28 hours, H. cupida reduced ~ 15μM of NaNO3 to non-detectable levels (Figure 1a). Nitrite values increased to 1.04μM in 8 hours and decreased to non-detectable levels in 24 hours (Figure 1b). Glucose decreased from 95μg.ml-1 to non...

  17. Genome evolution and systems biology in bacterial endosymbionts of insects

    OpenAIRE

    Belda Cuesta, Eugeni

    2010-01-01

    Gene loss is the most important event in the process of genome reduction that appears associated with bacterial endosymbionts of insects. These small genomes were derived features evolved from ancestral prokaryotes with larger genome sizes, consequence of a massive process of genome reduction due to drastic changes in the ecological conditions and evolutionary pressures acting on these prokaryotic lineages during their ecological transition to host-dependent lifestyle. In the present thesis, ...

  18. Exploring Evolution and Biology of Oomycetes: Integrative and Comparative Genomics

    OpenAIRE

    Seidl, M. F.

    2013-01-01

    Diseases that destroy livestock and crops have had catastrophic effects on human civilization, causing starvation and economical losses and continue to be a constant threat to global food production. Pathogenic species occur throughout the tree of life including many bacteria, eukaryotic microorganisms and metazoans. The fascinating taxonomic class of oomycetes unites several important pathogenic eukaryotes of plants and animals. We have witnessed considerable advances characterizing the (mol...

  19. Can Chimpanzee Biology Highlight Human Origin and Evolution?

    OpenAIRE

    Itai Roffman; Eviatar Nevo

    2010-01-01

    The closest living relatives of humans are their chimpanzee/bonobo (Pan) sister species, members of the same subfamily “Homininae”. This classification is supported by over 50 years of research in the fields of chimpanzee cultural diversity, language competency, genomics, anatomy, high cognition, psychology, society, self-consciousness and relation to others, tool use/production, as well as Homo level emotions, symbolic competency, memory recollection, complex multifaceted problem-solving cap...

  20. Models of Chemical Evolution

    OpenAIRE

    Matteucci, Francesca

    2003-01-01

    The basic principles underlying galactic chemical evolution and the most important results of chemical evolution models are discussed. In particular, the chemical evolution of the Milky Way galaxy, for which we possess the majority of observational constraints, is described. Then, it is shown how different star formation histories influence the chemical evolution of galaxies of different morphological type. Finally, the role of abundances and abundance ratios as cosmic clocks is emphasized an...