@article {149377, title = {Unraveling the genomic diversity and admixture history of captive tigers in the United States.}, journal = {Proc Natl Acad Sci U S A}, volume = {121}, year = {2024}, month = {2024 Sep 24}, pages = {e2402924121}, abstract = {

Genomic studies of endangered species have primarily focused on describing diversity patterns and resolving phylogenetic relationships, with the overarching goal of informing conservation efforts. However, few studies have investigated genomic diversity housed in captive populations. For tigers (), captive individuals vastly outnumber those in the wild, but their diversity remains largely unexplored. Privately owned captive tiger populations have remained an enigma in the conservation community, with some believing that these individuals are severely inbred, while others believe they may be a source of now-extinct diversity. Here, we present a large-scale genetic study of the private (non-zoo) captive tiger population in the United States, also known as "Generic" tigers. We find that the Generic tiger population has an admixture fingerprint comprising all six extant wild tiger subspecies. Of the 138 Generic individuals sequenced for the purpose of this study, no individual had ancestry from only one subspecies. We show that the Generic tiger population has a comparable amount of genetic diversity relative to most wild subspecies, few private variants, and fewer deleterious mutations. We observe inbreeding coefficients similar to wild populations, although there are some individuals within both the Generic and wild populations that are substantially inbred. Additionally, we develop a reference panel for tigers that can be used with imputation to accurately distinguish individuals and assign ancestry with ultralow coverage (0.25{\texttimes}) data. By providing a cost-effective alternative to whole-genome sequencing (WGS), the reference panel provides a resource to assist in tiger conservation efforts for both ex- and in situ populations.

}, keywords = {Animals, Animals, Zoo, Conservation of Natural Resources, Endangered Species, Genetic Variation, Genome, Genomics, Phylogeny, Tigers, United States}, issn = {1091-6490}, doi = {10.1073/pnas.2402924121}, author = {Armstrong, Ellie E and Mooney, Jazlyn A and Solari, Katherine A and Kim, Bernard Y and Barsh, Gregory S and Grant, Victoria B and Greenbaum, Gili and Kaelin, Christopher B and Panchenko, Katya and Pickrell, Joseph K and Rosenberg, Noah and Ryder, Oliver A and Yokoyama, Tsuya and Ramakrishnan, Uma and Petrov, Dmitri A and Hadly, Elizabeth A} } @article {36276, title = {The critically endangered forest owlet Heteroglaux blewitti is nested within the currently recognized Athene clade: A century-old debate addressed.}, journal = {PLoS One}, volume = {13}, year = {2018}, month = {2018}, pages = {e0192359}, abstract = {

Range-restricted species generally have specific niche requirements and may often have unique evolutionary histories. Unfortunately, many of these species severely lack basic research, resulting in poor conservation strategies. The phylogenetic relationship of the Critically Endangered Forest Owlet Heteroglaux blewitti has been the subject of a century-old debate. The current classifications based on non-phylogenetic comparisons of morphology place the small owls of Asia into three genera, namely, Athene, Glaucidium, and Heteroglaux. Based on morphological and anatomical data, H. blewitti has been alternatively hypothesized to belong within Athene, Glaucidium, or its own monotypic genus Heteroglaux. To test these competing hypotheses, we sequenced six loci (~4300 bp data) and performed phylogenetic analyses of owlets. Mitochondrial and nuclear trees were not congruent in their placement of H. blewitti. However, both mitochondrial and nuclear combined datasets showed strong statistical support with high maximum likelihood bootstrap (\>/ = 90) and Bayesian posterior probability values (\>/ = 0.98) for H. blewitti being nested in the currently recognized Athene group, but not sister to Indian A. brama. The divergence of H. blewitti from its sister taxa was between 4.3 and 5.7 Ma coinciding with a period of drastic climatic changes in the Indian subcontinent. This study presented the first genetic analysis of H. blewitti, a Critically Endangered species, and addressed the long debate on the relationships of the Athene-Heteroglaux-Glaucidium complex. We recommend further studies with more data and complete taxon sampling to understand the biogeography of Indian Athene species.

}, keywords = {Animals, Bayes Theorem, Conservation of Natural Resources, Endangered Species, Fossils, Phylogeny, Strigiformes}, issn = {1932-6203}, doi = {10.1371/journal.pone.0192359}, author = {Koparde, Pankaj and Mehta, Prachi and Reddy, Sushma and Ramakrishnan, Uma and Mukherjee, Shomita and Robin, V V} } @article {26575, title = {Non-sister Sri Lankan white-eyes (genus Zosterops) are a result of independent colonizations.}, journal = {PLoS One}, volume = {12}, year = {2017}, month = {2017}, pages = {e0181441}, abstract = {

Co-occurrence of closely related taxa on islands could be attributed to sympatric speciation or multiple colonization. Sympatric speciation is considered to be rare in small islands, however multiple colonizations are known to be common in both oceanic and continental islands. In this study we investigated the phylogenetic relatedness and means of origin of the two sympatrically co-occurring Zosterops white-eyes, the endemic Zosterops ceylonensis and its widespread regional congener Z. palpebrosus, in the island of Sri Lanka. Sri Lanka is a continental island in the Indian continental shelf of the Northern Indian Ocean. Our multivariate morphometric analyses confirmed the phenotypic distinctness of the two species. Maximum Likelihood and Bayesian phylogenetic analyses with ~2000bp from two mitochondrial (ND2 and ND3) and one nuclear (TGF) gene indicated that they are phylogenetically distinct, and not sister to each other. The two subspecies of the peninsula India; Z. p. egregius of Sri Lanka and India and Z. p. nilgiriensis of Western Ghats (India) clustered within the Z. palpebrosus clade having a common ancestor. In contrast, the divergence of the endemic Z. ceylonensis appears to be much deeper and is basal to the other Zosterops white-eyes. Therefore we conclude that the two Zosterops species originated in the island through independent colonizations from different ancestral lineages, and not through island speciation or multiple colonization from the same continental ancestral population. Despite high endemism, Sri Lankan biodiversity is long considered to be a subset of southern India. This study on a speciose group with high dispersal ability and rapid diversification rate provide evidence for the contribution of multiple colonizations in shaping Sri Lanka{\textquoteright}s biodiversity. It also highlights the complex biogeographic patterns of the South Asian region, reflected even in highly vagile groups such as birds.

}, keywords = {Animals, Bayes Theorem, Biodiversity, DNA, Mitochondrial, Evolution, Molecular, Genetic Speciation, Geography, Passeriformes, Phylogeny, Sri Lanka, Sympatry}, issn = {1932-6203}, doi = {10.1371/journal.pone.0181441}, author = {Wickramasinghe, Nelum and Robin, V V and Ramakrishnan, Uma and Reddy, Sushma and Seneviratne, Sampath S} } @article {875, title = {Higher speciation and lower extinction rates influence mammal diversity gradients in Asia.}, journal = {BMC Evol Biol}, volume = {15}, year = {2015}, month = {2015}, pages = {11}, abstract = {

BACKGROUND: Little is known about the patterns and correlates of mammal diversity gradients in Asia. In this study, we examine patterns of species distributions and phylogenetic diversity in Asia and investigate if the observed diversity patterns are associated with differences in diversification rates between the tropical and non-tropical regions. We used species distribution maps and phylogenetic trees to generate species and phylogenetic diversity measures for 1{\textdegree} {\texttimes} 1{\textdegree} cells across mainland Asia. We constructed lineage-through-time plots and estimated diversification shift-times to examine the temporal patterns of diversifications across orders. Finally, we tested if the observed gradients in Asia could be associated with geographical differences in diversification rates across the tropical and non-tropical biomes. We estimated speciation, extinction and dispersal rates across these two regions for mammals, both globally and for Asian mammals.

RESULTS: Our results demonstrate strong latitudinal and longitudinal gradients of species and phylogenetic diversity with Southeast Asia and the Himalayas showing highest diversity. Importantly, our results demonstrate that differences in diversification (speciation, extinction and dispersal) rates between the tropical and the non-tropical biomes influence the observed diversity gradients globally and in Asia. For the first time, we demonstrate that Asian tropics act as both cradles and museums of mammalian diversity.

CONCLUSIONS: Temporal and spatial variation in diversification rates across different lineages of mammals is an important correlate of species diversity gradients observed in Asia.

}, keywords = {Animals, Asia, Biodiversity, Genetic Speciation, Mammals, Phylogeny}, issn = {1471-2148}, doi = {10.1186/s12862-015-0289-1}, author = {Tamma, Krishnapriya and Ramakrishnan, Uma} }