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NESCent, The National Evolutionary Synthesis Center, is a collaborative effort of Duke University, The University of North Carolina at Chapel Hill and North Carolina State University and is sponsored by the National Science Foundation.
Last update10 min 11 sec ago
May 21, 2015
In the last two decades, models from evolutionary biology have made important contributions to demographic research on human fertility change. Within this evolutionary framework, two distinct traditions have focused on different processes of adaptation and time scales of change: (1) behavioral ecological perspectives have focused on how individual fertility decisions are shaped by local ecological circumstances, while (2) cultural evolutionary approaches have emphasized the role of socially transmitted information and changing social norms in shaping fertility behavior. While each tradition has made independent progress, research that integrates these approaches is necessary to improve our understanding of real fertility behavior, which results from a feedback between individual fertility decisions and social change. This approach requires combined attention to immediate ecological determinants of fertility decisions as well as the long-term processes that shape costs and benefits in a given environment. This workshop will bring together an international team of evolutionary behavioral scientists with complementary methodological and theoretical expertise in anthropology, psychology, and demography to develop (a) a synthetic article which proposes how these approaches can be integrated methodologically and theoretically, (b) an empirical article which applies our new synthetic framework to the study of fertility change in a particular fieldsite, demonstrating how the new methodological approach will work in practice and what we can learn through employing it, and (c) a multi-site grant proposal (UK, US, Bangladesh, Ethiopia, Bolivia, Poland) aimed at integrating and empirically testing these diverse evolutionary models of human fertility change.
May 17, 2015
Human cultural diversity is expressed in myriad ways (from social and marital norms to languages and religious practices), but what factors shape this diversity? Dating back to Darwin, multiple disciplines have debated the degree to which cultural diversity patterns are influenced by different factors, including history, demographics, and ecology. Over recent years an emerging set of studies have showcased how phylogenetic comparative methods from evolutionary biology can help resolve these long-held debates and revolutionize the field of cultural evolution. Now the major barrier to advances lies in the location of necessary data, which are spread across multiple disparate sources in linguistics, biogeography and anthropology. To overcome this challenge we will create D-PLACE (a Database of Phylogenies of Languages for the study of Cultural Evolution), a publicly available and expandable web-portal that will map over 100 cultural features onto language phylogenies and link these to ecological and environmental variables, empowering a whole new line of investigation into the drivers of cultural change and patterns of cultural diversity. We will produce a paper to introduce D-PLACE and outline the many types of questions in comparative anthropology the database can answer. Finally, we will demonstrate the power of this new resource by using D-PLACE to examine two long-standing and fundamental questions from comparative anthropology: (i) What drives the diversity of incest taboos (i.e. how human societies regulate who can mate and marry)? (ii) Can we characterize recurrent âhuman nichesâ, or are societies just arbitrary bundles of cultural features?
Linking self-fertilization, dispersal and distribution traits of species: Is Bakerâs law an exception to the rule?
Bakerâs Law (hereafter BL) states that self-compatible organisms are more likely to be successful colonizers after long-distance dispersal than self-incompatible organisms. This simple prediction draws a link between mating-system evolution and diverse fields of ecology and evolution such as dispersal biology and colonization, the evolution of range size and range limits, demography and Allee effect, and invasion biology. However, after >60 years of experimental research and theory development, the accumulated data yield varying, and often contradictory, support of BL. Our working group brings together a diverse array of researchers to assess predictions and assumptions of BL and elucidate ecological, evolutionary, and demographic parameters likely to determine the relationships between mating system, dispersal, and colonization success. To accomplish these goals we will: 1) Compile the voluminous literature on BL. 2) Link the BL data with two extensive databases gathered by prior NESCent support (seed germination and seed traits data; mating system data) and a NCEAS pollen limitation database. These expanded databases will include dispersal, range size, and life-history traits, thereby creating a powerful tool for testing various aspects of the relationship between mating-system and colonization success. 3) Employ macroevolutionary tools to map mating-system and dispersal traits onto the angiosperm phylogeny to assess evolutionary patterns and phylogenetically-corrected trait correlations. 4) Formalize BL using current population genetic theory and dispersal theory. Synthetic products of our working group should elucidate the links between dispersal and mating-system in colonization success, and will influence multiple fields of research in evolution for the foreseeable future.
May 10, 2015
Building non-model species genome curation communities
May 6, 2015
Primates are highly charismatic and often serve as flagship species in conservation efforts. They are also the closest living relatives of humans, and therefore hold the keys to resolving many questions about human evolution and ecology. However, the slow life histories of primates, combined with their complex social systems, their behavioral plasticity, and the challenging field conditions in which primate researchers must work, have severely limited analyses of mortality and fertility in wild, unprovisioned primate populations. This in turn limits comparative analyses that can shed light on the population dynamics and the social and ecological adaptations that have shaped both human and nonhuman primate evolution. We propose a Primate Life Histories Working Group to compare mortality and fertility schedules across taxa, to evaluate a set of hypotheses about the roles that phylogeny, ecology, and behavior play in shaping primate mortality and fertility patterns, and to examine whether life history theory predicts which vital rates are most variable across species. Using unique, individual-based life history data that have been collected from wild populations by nine working group participants over a minimum of 19 years, we will develop age-specific mortality and fertility schedules and create population projection matrices for each species. Our immediate goals are to test current hypotheses about the evolution of life histories in order to advance our understanding of primate evolution. Our longer-term goal is to move toward a collaborative, shared databank allowing analyses of irreplaceable life history data on wild primates.
April 28, 2015
A number of independent efforts have compiled global plant databases on functionally important traits of leaves, stems, seeds, and flowers. These databases are comprised of 1000's to tens of 1000's of species. With a few notable exceptions, they have not been analyzed in an evolutionary or phylogenetic context. However, when synthesized with a modern molecular phylogeny, these data could tell a comprehensive, multivariate story of the evolution of plant functional diversity. In this working group, we will merge multiple databases to explore the rate (tempo, sensu GG Simpson) of evolution of these traits and the best fit evolutionary model(s) (mode) underlying the trait diversification of land plants. We will ask 1. whether important divergences in trait space occurred along similar branches for different traits, 2. whether there were periods of evolution when trait diversification was especially rapid, and 3. whether there were interactions between trait evolution and rates of speciation and extinction. This work will lead to a new community resource of great interestâan internally synced trait matrixâmatched with the current state-of-the-art phylogeny. These data can then be synthesized with fossil evidence to explore whether the tempo and mode of trait evolution in extant and extinct taxa provide similar stories. Furthermore, these data will provide a powerful view into the coordinated (or lack thereof) evolution of ecologically important traits across vascular plantsâone of the most diverse and important lineages in the world today.
April 23, 2015
The identification and explanation of long-term evolutionary trends in higher taxa and biological communities is an important goal of biological research. Body size is the single most important ecological characteristic of metazoa and the variable most easily applied to analysis of evolutionary trends across distantly related taxa. The proposed working group will bring together paleobiologists studying body size evolution in deep time and across higher taxa with biologists studying the distribution of body sizes in living organisms from the community to global scale. The working group will initiate a community-wide database of body sizes through the Phanerozoic, an effort that requires standardized data on body size across higher taxa. The working group will also catalyze collaborations between paleobiologists and biologists to develop the theory necessary to investigate long-term dynamics in body-size evolution across diverse living and extinct metazoan lineages. The workshop will provide a venue for members to address the relationships between the pattern of body size evolution and the distribution of body sizes in extant organisms. How well can macroevolutionary patterns be inferred from macroecological ones? How well do those patterns reflect evolutionary mechanisms, whether driven or passive? Ultimately, the resulting database will become a broadly applicable and dynamic resource for macroevolutionary research, with real potential to help future workers shed light on the forces that have shaped the evolutionary trajectory of animal life on Earth.
April 12, 2015
Although the Indian and Pacific Oceans (hereafter Indo-Pacific) have long been recognized as containing the majority of marine biodiversity, their vastness poses substantial challenges for empirical research. Syntheses of published data, however, can expand the geographic scope of inference. We plan to examine the recent evolution of Indo-Pacific taxa by drawing upon all available population genetic data. We have two immediate research goals: 1) compile and analyze existing datasets for multiple species using consistent and uniform methods of analysis that represent the best current practice in population genetics to better determine oceanographic and geographic features as well as biological traits correlated with population structure. These results will inform our understanding of evolutionary processes in the region and provide information directly relevant to managers and conservation organizations. We will also: 2) conduct the first large scale multispecies investigation to infer the geography of speciation among Indo-Pacific taxa that incorporates population genetic inferences, thus testing predictions of competing biogeographic hypotheses using a novel approach. These research goals are underpinned by the creation of a database that would become publicly accessible to facilitate future studies. In addition, we plan to develop a virtual collaboration space that will support international collaborations in genetic-based research, training, and education throughout the region.
March 18, 2015
March 15, 2015
NESCent is sponsoring a hackathon to be held at NESCent in Durham, North Carolina, on March 16-20, 2015, with the objective to help foster an interoperating ecosystem of scalable tools and resources for population genetics data analysis in the popular R platform. The event is designed to target interoperability, scalability, and workflow building challenges among the many population genetics R packages that already exist. The gathering provides an opportunity for a diverse group of population genetics researchers, method developers, and people with other relevant areas of expertise to collaborate on code, documentation, use-cases, and other resources that will aid their communities.
March 11, 2015
The potential for synthetic research based on aggregating, integrating, and re-using data is enormous, yet most resources remain interoperable. To realize this potential, software and databases that handle evolutionary trees (and their associated annotations) must be interoperable. Interoperability, in turn, requires tools based on common standards. In the past few years, evolutionary informaticists, with help from NESCent, have been building a software toolbox for solving interoperability problems, based on the EvoIO âstackâ of NeXML, CDAO and PhyloWS. This toolbox makes it possible to begin building a worldwide network of interoperable evolutionary resources. The HIP (Hackathons, Interoperability, Phylogenies) aims to use the hackathon mechanism (which we have helped to develop at NESCent) to grow this network directly, by adding links to it, and indirectly, by creating examples for others to follow. To support this project within a working-group budget, we leverage support from strategic partners. Each of the planned series of 3 hackathons will bring together scientific programmers with related challenges. The hackathons target early-career scientists, who often have the most technical expertise and the most potential to pass along their skills and enthusiasm.
March 8, 2015
February 26, 2015
Evolutionary biology is a foundational and integrative science for medicine, but few physicians or medical researchers are familiar with its most relevant principles. While undergraduate students have increasing opportunities to learn about the interface of evolution, health, and disease, most premedical students have scant room for electives in their schedules, few premed prerequisite courses incorporate evolutionary thinking, and no medical school develops these competencies. The overarching goal of this Working Group is to lay the groundwork for future endeavors by providing testable models and pathways for infusing premedical and medical education with evolutionary thinking. This Working Group, an interdisciplinary, international, and intergenerational group of physicians, scientists, educators, and students, will 1) define core competencies in evolutionary biology for physicians and other health professionals; 2) investigate the ability of current curricula to prepare health professionals to meet these standards; 3) identify âteachable momentsâ that provide opportunities to integrate evolutionary principles into premedical and medical curricula; 4) design model curricula and learning experiences that can advance evolutionary education for health professionals; and 5) provide open access to these resources and disseminate them. The Working Group will be supported by an Advisory Committee of senior academic leaders and stakeholders. These efforts will not be sufficient in themselves, but they will establish the intellectual platform from which educational interventions on student learning, and scientific and clinical problem solving, can be developed and tested.
Americans are far less accepting of human evolution than other realms of evolution; yet, human evolution and our common ancestry with other animals are increasingly relevant to medicine and our daily lives. We propose a NESCent working group made up of scientists, educators, and a journalist that will be devoted to enhancing communication of these health-related applications of human evolution to diverse audiences. Planned activities include discussion of methodological approaches designed to best communicate these ideas, design of teacher workshops, writing publications geared to each of these audiences, and discussion regarding collaboration with museums (in particular, the Smithsonian Institution) and zoos. In these activities, we will take a systematic scholarly approach using evidence-based methods to foster communication of principles of human evolution to these diverse audiences.
February 22, 2015
It is easily demonstrable that organisms with rapid, appropriate plastic responses to environmental change will prevail over genotypes with fixed phenotypes. It is also accepted that the general dearth of organisms successful across a wide environmental range indicates fundamental limits to or costs of plasticity. The nature of constraining factors has been broadly discussed (DeWitt et al. 1998), and numerous studies have been done to quantify them. However, a curious pattern has emerged: although hypothesized to be widespread, costs are absent more often than they are detected. The issue of costs of plasticity (CoP) lies at the intersection of a range of evolutionary and ecological questions: What are the limits to plasticity? Are CoP associated with life history tradeoffs? Are CoP expected in all environments? Does plasticity enhance invasiveness? etc. This working group will address two fundamental questions. 1) Are the expectations that costs of plasticity should be universal well-founded (i.e., the Âno free lunchÂ principle)? Several authors have proposed that, in situations where the intensity of selection for adaptive plasticity is strong, there should be corresponding pressure to ameliorate costs. 2) Independently of the answer to the first question, Are analytical and experimental methods for detecting CoP appropriate or sufficiently sensitive? CoP have most often been studied using common garden style plasticity experiments and analyzed via van TienderenÂs (1991) multiple regression approach.
February 10, 2015
A working group to solve problems in model selection and phylogeny in mixed multi-factor meta-analysis
Meta-analysis is a statistical technique used for syntheses of results from numerous independent studies. Increasingly, evolutionary biologists need to perform meta-analysis in which the effects of numerous explanatory variables on a response variable of interest are considered, taking into account the evolutionary history of the species in the dataset. However, such analyses require analysis of numerous complex statistical models, and methods for such analyses have not been previously developed. Our working group is developing these methods and applying them to understand local adaptation, context-dependency, and the influence of evolutionary relationships on outcomes of symbiosis between plants and mycorrhizal fungi.
January 14, 2015
When a seed germinates determines the seasonal environment experienced by a plant throughout its life, and germination phenology is one of the very first phenotypes expressed by plants during ontogeny. As such, germination phenology is subject to extremely strong natural selection, especially during early stages of adaptation. Moreover, germination co-evolves with seed dispersal, mating system, and reproductive strategy to determine plant life cycles and demographic dynamics of plant populations. This working group will test the importance of germination adaptations in delimiting species niche and range limits, both in the past and in response to changed environments. More generally, this topic pertains to the identification of key traits associated with adaptation to environmental change, and the role that early life-stage traits and traits associated with habitat selection contribute to these dynamics. The focus on germination provides a clear and tractable system for addressing general evolutionary and ecological questions concerning the interactions between ontogeny and adaptation, trait coevolution, and the roles of habitat selection and organismal responses to their environment in niche evolution. It also will contribute tangibly to efforts to predict plant responses to environmental change. The group will compile and analyze a comprehensive data set on germination and dormancy, combined with data on niche breadth, geographic range, and life history, in order to test hypotheses concerning trait coevolution and species range limits. The group will also theoretically explore interactions between ontogeny and adaptation, theoretically model trait coevolution via habitat selection and bet hedging, and develop phenological models of integrated life histories that include germination in order to predict plant responses to environmental change.
January 13, 2015
Humans are vulnerable to a number of unique musculoskeletal maladies as a consequence of our evolutionary history. Although walking on our extended hind limbs is the hallmark adaptation characterizing our species it nevertheless makes us vulnerable to a wide range of serious joint and soft tissue problems. When viewed from an evolutionary perspective many of these medical issues become understandable and, indeed, novel methods of diagnosis and treatment can emerge. The proposed collaborative, a working group of paleoanthropologists, comparative anatomists, biomechanical engineers, and physicians will create new analytical approaches and new ways of viewing the disorders that uniquely plague our species. The results of this work include the development and implementation of a model curriculum, the creation of a website, and the publication of an edited volume. The disorders directly related to our way of walking include chronically sprained ankles, hernias, osteoporotic fractures of the hip, spine, and forearm, obstetric problems, knee problems, foot disorders, fatigue fractures, and many others. By understanding how our anatomy changed in order to walk upright, and why these changes occurred, we gain a better understanding of why these adaptations sometimes go awry resulting in disorders and pain.
The Genealogical World of Phylogenetic Networks
BMC Evolutionary Biology