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Jonathan B. Losos

Bio: Jonathan B. Losos is an academic researcher from Washington University in St. Louis. The author has contributed to research in topics: Anolis & Adaptive radiation. The author has an hindex of 89, co-authored 274 publications receiving 28673 citations. Previous affiliations of Jonathan B. Losos include University of California, Davis & Avila University.


Papers
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Book ChapterDOI
15 Aug 2009

5 citations

01 Mar 2020
TL;DR: In this article, the authors compared relative abundance and escape behavior of Sciurus carolinensis (Eastern Gray Squirrels) in common urban habitats in St. Louis, Missouri, USA and found that squirrels were abundant in urban park, forest, and neighborhood habitats and nearly absent in cemeteries and golf courses.
Abstract: Behavioral responses to urbanization may differ with environmental variation across metropolitan areas. We compared relative abundance and escape behavior of Sciurus carolinensis (Eastern Gray Squirrels) in common urban habitats in St. Louis, Missouri, USA. We found that squirrels were abundant in urban park, forest, and neighborhood habitats and nearly absent in cemeteries and golf courses. Across all sites, we found abundance was positively associated with anthropogenic habitat modification: more people, impervious surface cover, roads, high intensity developed land use, and less canopy cover. Escape responses also varied across the urban landscape. Flight initiation distance, a metric of risk perception, was least in neighborhood and forest habitats and greatest in park and cemetery habitats. Most squirrels fled by sprinting a short distance and stopping in all habitat types, and those that ran quickly to a refuge tended to have greater flight initiation distances. Squirrels more readily fled in habitats with fewer roads and more residential land use. These findings suggest that responses to urbanization in Eastern Gray Squirrels are heterogeneous within the metropolitan region.

5 citations

Journal ArticleDOI
TL;DR: In this paper , the authors provide a detailed investigation of the genomic basis of rapid adaptation in a species that thrives in urban environments, and identify putative genomic targets of natural selection related to functionally relevant traits.
Abstract: Significance Urbanization drastically transforms landscapes worldwide, leading to altered eco-evolutionary dynamics. Many organisms are tolerant of, and even adapt to, these novel environments, presenting opportunities to study evolutionary change over rapid timescales. Here we provide a detailed investigation of the genomic basis of rapid adaptation in a species that thrives in urban environments. Integrating environmental, phenotypic, and genomic data, we demonstrate that populations exposed to similar environmental modification across distinct genetic clusters exhibit parallel phenotypic divergence underlain by parallel genomic divergence. We identify putative genomic targets of natural selection related to functionally relevant traits, thus helping to elucidate the mechanisms of rapid adaptive evolution of complex traits at the genomic level.

5 citations

Posted ContentDOI
29 Mar 2017-bioRxiv
TL;DR: Using posterior probabilities, it is found that the fossil anoles have different semicircular canals shapes to modern ecomorph groupings implying extinct anoles may have been interacting with their Miocene environment in different ways to modern Anolis species.
Abstract: Anolis lizards are a model system for the study of adaptive radiation and convergent evolution. Greater Antillean anoles have repeatedly evolved six similar forms or ecomorphs: crown-giant, grass-bush, twig, trunk, trunk-crown, and trunk-ground. Members of each ecomorph category possess a specific set of morphological, ecological and behavioural characteristics which have been acquired convergently. Here we test whether the semicircular canal system - the organ of balance - is also convergent among ecomorphs, reflecting the shared sensory requirements of their ecological niches. As semicircular canal shape has been shown to reflect different locomotor strategies, we hypothesised that each Anolis ecomorph would have a unique canal morphology. Using 3D semilandmarks and geometric morphometrics, semicircular canal shape was characterised in 41 Anolis species from the Greater Antilles and the relationship between canal shape and ecomorph grouping, phylogenetic history, size, and perch characteristics was assessed. Further, canal morphology of modern species was used to predict the ecomorph affinity of five fossil anoles from the Miocene of the Dominican Republic. Our study recovered ecomorph as the single-most important covariate of canal morphology in modern taxa; although phylogenetic history and size also showed a small, yet significant correlation with shape. Surprisingly, perch characteristics were not found to be significant covariates of canal shape, even though they are important habitat variables. Using posterior probabilities, we found that the fossil anoles have different semicircular canals shapes to modern ecomorph groupings implying extinct anoles may have been interacting with their Miocene environment in different ways to modern Anolis species.

5 citations

Journal ArticleDOI
TL;DR: This article revisits a little-known article in The American Naturalist published in 1970, which presents one of the earliest demonstrations of the potential benefits of applying information theory to animal communication and demonstrates the insights that can be gained by evaluating signal evolution at the level of the community.
Abstract: Why are animal signals so complex? This question continues to attract the interest of behavioral and evolutionary ecologists. In this Countdown article, we revisit a littleappreciated article in The American Naturalist published in 1970: “An Estimation of Redundancy and Information Content of Anole Dewlaps” by A. Stanley Rand and Ernest E. Williams (fig. 1). As part of this piece, Rand and Williams argued that signal complexity can be explained by redundancy, a mechanism by which multiple components of the signals have evolved to increase the probability of eliciting a response from an intended receiver. We highlight this work because it presents one of the earliest demonstrations of the potential benefits of applying information theory to animal communication. In addition, the study demonstrates the insights that can be gained by evaluating signal evolution at the level of the community. Even today, when both theoretical and empirical studies evaluating the potential forces leading to signal diversity have flourished, evaluations at the community level are extremely rare. More generally, in the spirit of the American Society of Naturalists, we wish to emphasize that the perspicacity of Rand and Williams resulted from the fact that their ideas were ultimately derived from a deep understanding of the natural history of their study organism. In particular, Stan Rand spent substantial time in the field observing lizards, including 10 months studying the ecology and social dynamics of the Jamaican lizard Anolis lineatopus. This study reported detailed observations of many aspects of behavior, including detailed descriptions of the signaling displays used during intraand interspecific interactions (A. S. Rand, 1967, “Ecology and Social Organization in the Iguanid Liz-

5 citations


Cited by
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28 Jul 2005
TL;DR: PfPMP1)与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作�ly.
Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1(PfPMP1)与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员,通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

18,940 citations

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 Article
TL;DR: For the next few weeks the course is going to be exploring a field that’s actually older than classical population genetics, although the approach it’ll be taking to it involves the use of population genetic machinery.
Abstract: So far in this course we have dealt entirely with the evolution of characters that are controlled by simple Mendelian inheritance at a single locus. There are notes on the course website about gametic disequilibrium and how allele frequencies change at two loci simultaneously, but we didn’t discuss them. In every example we’ve considered we’ve imagined that we could understand something about evolution by examining the evolution of a single gene. That’s the domain of classical population genetics. For the next few weeks we’re going to be exploring a field that’s actually older than classical population genetics, although the approach we’ll be taking to it involves the use of population genetic machinery. If you know a little about the history of evolutionary biology, you may know that after the rediscovery of Mendel’s work in 1900 there was a heated debate between the “biometricians” (e.g., Galton and Pearson) and the “Mendelians” (e.g., de Vries, Correns, Bateson, and Morgan). Biometricians asserted that the really important variation in evolution didn’t follow Mendelian rules. Height, weight, skin color, and similar traits seemed to

9,847 citations

Journal ArticleDOI
TL;DR: A new, multifunctional phylogenetics package, phytools, for the R statistical computing environment is presented, with a focus on phylogenetic tree-building in 2.1.
Abstract: Summary 1. Here, I present a new, multifunctional phylogenetics package, phytools, for the R statistical computing environment. 2. The focus of the package is on methods for phylogenetic comparative biology; however, it also includes tools for tree inference, phylogeny input/output, plotting, manipulation and several other tasks. 3. I describe and tabulate the major methods implemented in phytools, and in addition provide some demonstration of its use in the form of two illustrative examples. 4. Finally, I conclude by briefly describing an active web-log that I use to document present and future developments for phytools. I also note other web resources for phylogenetics in the R computational environment.

6,404 citations

Journal ArticleDOI
TL;DR: Analysis of variance of log K for all 121 traits indicated that behavioral traits exhibit lower signal than body size, morphological, life-history, or physiological traits, and this work presents new methods for continuous-valued characters that can be implemented with either phylogenetically independent contrasts or generalized least-squares models.
Abstract: The primary rationale for the use of phylogenetically based statistical methods is that phylogenetic signal, the tendency for related species to resemble each other, is ubiquitous. Whether this assertion is true for a given trait in a given lineage is an empirical question, but general tools for detecting and quantifying phylogenetic signal are inadequately developed. We present new methods for continuous-valued characters that can be implemented with either phylogenetically independent contrasts or generalized least-squares models. First, a simple randomization procedure allows one to test the null hypothesis of no pattern of similarity among relatives. The test demonstrates correct Type I error rate at a nominal α = 0.05 and good power (0.8) for simulated datasets with 20 or more species. Second, we derive a descriptive statistic, K, which allows valid comparisons of the amount of phylogenetic signal across traits and trees. Third, we provide two biologically motivated branch-length transformat...

3,896 citations