A field-based analysis of the accuracy of niche models applied to the fossil record

The use of ecological niche modeling (ENM) to estimate the geographic ranges of species is widely employed with modern fauna and is becoming more widespread in paleontology. Herein, field validation is utilized to assess the predictive accuracy of ENM methods for Paleozoic brachiopod species. This study represents the first field validation analysis of ENM methods in the fossil record. Previously published species distributions models for 8 Late Ordovician brachiopod species from the Cincinnati, Ohio region (United States) developed using GARP (Genetic Algorithm using Rule-set Prediction) were assessed for accuracy by comparing species occurrence data from a newly available set of 18 localities with the original species distribution models. Based on this data, the statistical significance of the original model set was assessed; 18 of the 22 original models were demonstrated to be statistically significant, based on field validation. Of the 140 individual species occurrences assessed, 60.8% were accurately predicted, 9.2% exhibited over prediction, and 30% exhibited under prediction. Accurate results were more common for species modeled from the greatest number of species occurrence points. The least accurate species models developed were for eurytopic species or those for which taxonomic affinities are unclear. Results indicate that with ample outcrop, well-defined stratigraphy, and sufficient fossil occurrence data, ENM methods could be successfully applied to many intervals in Earth history

Frontiers of Biogeography:Taking its place as a journal of choice for the publication of high quality biogeographical research articles

Through this editorial we seek your support and engagement as authors, readers and reviewers as we take the next steps in developing Frontiers of Biogeography as a leading international journal of biogeography and related subdisciplines. Here we make the case for submitting your next contribution to this journal: affordable, gold libre, open access, with the support of a disciplinarily-informed editorial and review team, which returns benefits to the biogeography community.Peer Reviewe

Requirement of a Membrane Potential for the Posttranslational Transfer of Proteins into Mitochondsria

Posttranslational transfer of most precursor proteins into mitochondria is dependent on energization of the mitochondria. Experiments were carried out to determine whether the membrane potential or the intramitochondrial ATP is the immediate energy source. Transfer in vitro of precursors to the ADP/ATP carrier and to ATPase subunit 9 into isolated Neurospora mitochondria was investigated. Under conditions where the level of intramitochondrial ATP was high and the membrane potential was dissipated, import and processing of these precursor proteins did not take place. On the other hand, precursors were taken up and processed when the intramitochondrial ATP level was low, but the membrane potential was not dissipated. We conclude that a membrane potential is involved in the import of those mitochondrial precursor proteins which require energy for intracellular translocatio

A second horizon scan of biogeography:golden ages, Midas touches, and the Red Queen

Are we entering a new ‘Golden Age’ of biogeography, with continued development of infrastructure and ideas? We highlight recent developments, and the challenges and opportunities they bring, in light of the snapshot provided by the 7th biennial meeting of the International Biogeography Society (IBS 2015). We summarize themes in and across 15 symposia using narrative analysis and word clouds, which we complement with recent publication trends and ‘research fronts’. We find that biogeography is still strongly defined by core sub-disciplines that reflect its origins in botanical, zoological (particularly bird and mammal), and geographic (e.g., island, montane) studies of the 1800s. That core is being enriched by large datasets (e.g. of environmental variables, ‘omics’, species’ occurrences, traits) and new techniques (e.g., advances in genetics, remote sensing, modeling) that promote studies with increasing detail and at increasing scales; disciplinary breadth is being diversified (e.g., by developments in paleobiogeography and microbiology) and integrated through the transfer of approaches and sharing of theory (e.g., spatial modeling and phylogenetics in evolutionary–ecological contexts). Yet some subdisciplines remain on the fringe (e.g., marine biogeography, deep-time paleobiogeography), new horizons and new theory may be overshadowed by popular techniques (e.g., species distribution modelling), and hypotheses, data, and analyses may each be wanting. Trends in publication suggest a shift away from traditional biogeography journals to multidisciplinary or open access journals. Thus, there are currently many stewardship of, the planet (e.g., Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services). As in the past, biogeographers doubtless will continue to be engaged by new data and methods in exploring the nexus between biology and geography for decades into the future. But golden ages come and go, and they need not touch every domain in a discipline nor affect subdisciplines at the same time; moreover, what appears to be a Golden Age may sometimes have an undesirable ‘Midas touch’. Contexts within and outwith biogeography—e.g., methods, knowledge, climate, biodiversity, politics—are continually changing, and at times it can be challenging to establish or maintain relevance. In so many races with the Red Queen, we suggest that biogeography will enjoy greatest success if we also increasingly engage with the epistemology of our disciplinePeer reviewe

Species' geographic distributions through time: Playing catchup with changing climates

This is the author's accepted manuscript.Species’ ranges are often treated as a rather fixed characteristic, rather than a fluid, ever-changing manifestation of their ecological requirements and dispersal abilities. Paleontologists generally have had a more flexible point of view on this issue than neontologists, but each perspective can improve by appreciating the other. Here, we provide an overview of paleontological and neontological perspectives on species’ geographic distributions, focusing on what can be learned about historical variations in distributions. The cross-disciplinary view, we hope, offers some novel perspectives on species-level biogeography

Global cooling as a driver of diversification in a major marine clade

Climate is a strong driver of global diversity and will become increasingly important as human influences drive temperature changes at unprecedented rates. Here we investigate diversification and speciation trends within a diverse group of aquatic crustaceans, the Anomura. We use a phylogenetic framework to demonstrate that speciation rate is correlated with global cooling across the entire tree, in contrast to previous studies. Additionally, we find that marine clades continue to show evidence of increased speciation rates with cooler global temperatures, while the single freshwater clade shows the opposite trend with speciation rates positively correlated to global warming. Our findings suggest that both global cooling and warming lead to diversification and that habitat plays a role in the responses of species to climate change. These results have important implications for our understanding of how extant biota respond to ongoing climate change and are of particular importance for conservation planning of marine ecosystems

On the Use of Semantic-Based AIG to Automatically Generate Programming Exercises

In introductory programming courses, proficiency is typically achieved through substantial practice in the form of relatively small assignments and quizzes. Unfortunately, creating programming assignments and quizzes is both, time-consuming and error-prone. We use Automatic Item Generation (AIG) in order to address the problem of creating numerous programming exercises that can be used for assignments or quizzes in introductory programming courses. AIG is based on the use of test-item templates with embedded variables and formulas which are resolved by a computer program with actual values to generate test-items. Thus, hundreds or even thousands of test-items can be generated with a single test-item template. We present a semantic-based AIG that uses linked open data (LOD) and automatically generates contextual programming exercises. The approach was incorporated into an existing self-assessment and practice tool for students learning computer programming. The tool has been used in different introductory programming courses to generate a set of practice exercises different for each student, but with the same difficulty and quality