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A. Townsend Peterson

Bio: A. Townsend Peterson is an academic researcher from University of Kansas. The author has contributed to research in topics: Environmental niche modelling & Ecological niche. The author has an hindex of 91, co-authored 521 publications receiving 51524 citations. Previous affiliations of A. Townsend Peterson include California Academy of Sciences & University of Chicago.


Papers
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Journal ArticleDOI
TL;DR: A new species of Scytalopus tapaculo is described from the temperate humid montane forests of Junín Department, Peru, which has a unique song that differs strikingly from that of any known ScyTalopus species, consisting of a rapidly repeated series of ascending phrases.
Abstract: We describe a new species of Scytalopus tapaculo (Aves: Passeriformes: Rhinocryptidae) from the temperate humid montane forests (2,400–3,200 m) of Junin Department, Peru. This species has a unique song that differs strikingly from that of any known Scytalopus species, consisting of a rapidly repeated series of ascending phrases. Phenotypically, the new species is uniformly blackish in color and small-to-medium in size, most similar to members of the allopatric S. latrans complex. At least six species of Scytalopus occur along an elevational gradient on the eastern slopes of the Andes in Junin; in the vicinity of the type locality, the new species replaces S. femoralis at 2,400–2,500 m, and is replaced by S. acutirostris at 2,900–3,200 m. Throughout its elevational range, the new species is broadly syntopic with the larger S. macropus. This species is currently known from a single river drainage; although it probably occurs more broadly, it is likely a range-restricted species endemic to central Peru.

16 citations

Journal ArticleDOI
TL;DR: Sand fly populations of different ecological niches in the Amaraji endemic American Cutaneous Leishmaniasis focus of the Pernambuco Atlantic Forest region of northeastern Brazil were monitored spatiotemporally to suggest that L. whitmani may potentially be the principal vector of ACL in the region.
Abstract: Sand fly populations of different ecological niches in the Amaraji endemic American Cutaneous Leishmaniasis (ACL) focus of the Pernambuco Atlantic Forest region of northeastern Brazil were monitored spatiotemporally. Lutzomyia whitmani was dominant in all niches but occurred in smaller numbers in forested locations. L. whitmani was significantly less seasonal than the other species, being present throughout the year while other species were more abundant between February and April. These results suggest that L. whitmani may potentially be the principal vector of ACL in the region, even though the sand fly fauna was diverse: 88% were L.whitmani and 12% belonged to 11 other species. Two other species, L. complexa (1.3%) and L. migonei (0.8%), considered to be ACL vectors in other regions, were also present. This detailed picture of the sand fly populations abundance and spatiotemporal distribution provides a basis for future modeling studies of forecasting sand fly activity patterns and ACL occurence.

16 citations

Journal ArticleDOI
TL;DR: A more appropriate error weighting scheme for niche modeling analyses shows a simpler distribution of the black-legged tick, in which the species ranges continuously across eastern North America; this distributional pattern is supported by independent occurrence data from the eastern Great Plains.
Abstract: The black-legged tick, Ixodes scapularis Say, is the primary vector of Borrelia burgdorferi, a spirochete that causes Lyme disease, in eastern North America. Lyme disease risk has generally been considered to be focused in the Northeast and the northern Midwest in the United States, yet the distribution of the vector extends considerably more broadly. A recent analysis of the distribution of the species using ecological niche modeling approaches painted an odd biogeographic picture, in which the species is distributed in a "rimming" distribution across the northern Midwest and Northeast, and along the Atlantic and Gulf coasts of the eastern United States, but not broadly in the interior of eastern North America. Here, we reanalyze the situation for this species, and demonstrate that the distribution estimated in the previous study was a consequence of assumptions about relative weights applied to different error types. A more appropriate error weighting scheme for niche modeling analyses, in which omission error is prioritized over commission error, shows a simpler distribution, in which the species ranges continuously across eastern North America; this distributional pattern is supported by independent occurrence data from the eastern Great Plains, in Kansas. We discuss implications for public health planning and intervention across the region, as well as for developing effective and predictive maps of vector distributions and pathogen transmission risk.

16 citations

Journal ArticleDOI
TL;DR: Based on strong differences in plumage coloration between coastal California and Great Basin populations of Scrub Jays, museum specimens representing gene flow between the two forms are identified and an important assumption of most theoretical treatments of the effects of gene flow is violated.
Abstract: Based on strong differences in plumage coloration between coastal California (californica subspecies group) and Great Basin (woodhouseii subspecies group) populations of Scrub Jays (Aphelocoma coerulescens), museum specimens representing gene flow between the two forms are identified. A total of 27 examples of apparent genetic exchange between two forms (individuals of one subspecies group taken within the range of the other) is documented. Immigration rates are on the order of one per hundred or one per thousand individuals, a rate sufficient to prevent differentiation by genetic drift alone if effective population sizes are in the range of 100-550 individuals. Gene flow east-to-west across the Mojave Desert is two to seven times stronger than west-to-east movement. This directional bias has theoretical implications because an important assumption (symmetry of gene flow patterns) of most theoretical treatments of the effects of gene flow is violated. If effective population sizes are comparable in the two forms, then the bias in gene flow should lead to an overall greater rate of differentiation in the genetically more isolated woodhouseii populations.

16 citations

Journal Article
TL;DR: It is suggested that maturation rates do not track sociality closely and that the occurrence of delayed maturation of soft-part coloration in some New World jay taxa may best be accounted for by phylogenetic inertia.
Abstract: ABSTRAcr. -To test the hypothesis that heterochronic changes in color maturation act to integrate avian social groups, the relationship between social-group size and maturation rates of four morphological characters was analyzed in the blue-and-black jays (Cyanocorax spp., formerly Cissilopha). Contrary to patterns found in the New World jay assemblage as a whole and to theoretical predictions, sociality and maturation rates are uncorrelated within the blue-and-black jays. Such a relationship is also lacking in at least one of the other two New World jay lineages that exhibit delayed soft-part color maturation. These results suggest that maturation rates do not track sociality closely and that the occurrence of delayed maturation of soft-part coloration in some New World jay taxa may best be accounted for by phylogenetic inertia. Received 9 May 1990, accepted 10 Sept. 1990.

16 citations


Cited by
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Journal ArticleDOI
TL;DR: Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols used xiii 1.
Abstract: Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols Used xiii 1. The Importance of Islands 3 2. Area and Number of Speicies 8 3. Further Explanations of the Area-Diversity Pattern 19 4. The Strategy of Colonization 68 5. Invasibility and the Variable Niche 94 6. Stepping Stones and Biotic Exchange 123 7. Evolutionary Changes Following Colonization 145 8. Prospect 181 Glossary 185 References 193 Index 201

14,171 citations

Journal ArticleDOI
TL;DR: In this paper, the use of the maximum entropy method (Maxent) for modeling species geographic distributions with presence-only data was introduced, which is a general-purpose machine learning method with a simple and precise mathematical formulation.

13,120 citations

Journal Article
Fumio Tajima1
30 Oct 1989-Genomics
TL;DR: It is suggested that the natural selection against large insertion/deletion is so weak that a large amount of variation is maintained in a population.

11,521 citations

Journal ArticleDOI
TL;DR: The Bayesian Evolutionary Analysis by Sampling Trees (BEAST) software package version 1.7 is presented, which implements a family of Markov chain Monte Carlo algorithms for Bayesian phylogenetic inference, divergence time dating, coalescent analysis, phylogeography and related molecular evolutionary analyses.
Abstract: Computational evolutionary biology, statistical phylogenetics and coalescent-based population genetics are becoming increasingly central to the analysis and understanding of molecular sequence data. We present the Bayesian Evolutionary Analysis by Sampling Trees (BEAST) software package version 1.7, which implements a family of Markov chain Monte Carlo (MCMC) algorithms for Bayesian phylogenetic inference, divergence time dating, coalescent analysis, phylogeography and related molecular evolutionary analyses. This package includes an enhanced graphical user interface program called Bayesian Evolutionary Analysis Utility (BEAUti) that enables access to advanced models for molecular sequence and phenotypic trait evolution that were previously available to developers only. The package also provides new tools for visualizing and summarizing multispecies coalescent and phylogeographic analyses. BEAUti and BEAST 1.7 are open source under the GNU lesser general public license and available at http://beast-mcmc.googlecode.com and http://beast.bio.ed.ac.uk

9,055 citations

Journal ArticleDOI
TL;DR: Range-restricted species, particularly polar and mountaintop species, show severe range contractions and have been the first groups in which entire species have gone extinct due to recent climate change.
Abstract: Ecological changes in the phenology and distribution of plants and animals are occurring in all well-studied marine, freshwater, and terrestrial groups These observed changes are heavily biased in the directions predicted from global warming and have been linked to local or regional climate change through correlations between climate and biological variation, field and laboratory experiments, and physiological research Range-restricted species, particularly polar and mountaintop species, show severe range contractions and have been the first groups in which entire species have gone extinct due to recent climate change Tropical coral reefs and amphibians have been most negatively affected Predator-prey and plant-insect interactions have been disrupted when interacting species have responded differently to warming Evolutionary adaptations to warmer conditions have occurred in the interiors of species’ ranges, and resource use and dispersal have evolved rapidly at expanding range margins Observed genetic shifts modulate local effects of climate change, but there is little evidence that they will mitigate negative effects at the species level

7,657 citations