Publications by authors named "Michael V Westbury"

To evaluate the presence of domesticated camelids in the Semiarid North of Chile (29°S) before the arrival of the Inca, we utilized a multidisciplinary approach to analyze 57 South American camelids that were part of the funerary contexts of the El Olivar site, dated between 1,155 and 1,538 cal AD and associated with the Diaguita Culture. The analyses included osteometric data, age profiles, sex estimation, genetic analysis, identification of pathologies, isotopic analysis and dental calculus analysis. The results indicate a higher frequency of juvenile-adult and adult animals, together with a relatively similar proportion of males and females.

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The genomic study of specimens dating to the Early and Middle Pleistocene (EP and MP), a period spanning from 2.6 million years ago (Ma) to 126 thousand years ago (ka), has the potential to elucidate the evolutionary processes that shaped present-day biodiversity. Obtaining genomic data from this period is challenging, but mitochondrial DNA, given its higher abundance compared to nuclear DNA, could play an important role to understand evolutionary processes at this time scale.

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Koalas are arboreal herbivorous marsupials, endemic to Australia. During the late 1800s and early 1900s, the number of koalas declined dramatically due to hunting for their furs. In addition, anthropogenic activities have further decimated their available habitat, and decreased population numbers.

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The polar bear (Ursus maritimus) occupies a relatively narrow ecological niche, with many traits adapted for cold temperatures, movement across snow, ice and open water, and for consuming highly lipid-dense prey species. The divergence of polar bears from brown bears (Ursus arctos) and their adaptation to their Arctic lifestyle is a well-known example of rapid evolution. Previous research investigating whole genomes uncovered twelve key genes that are highly differentiated between polar and brown bears, show signatures of selection in the polar bear lineage, and are associated with polar bear adaptation to the Arctic environment.

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Beluga whales play a critical role in the subsistence economies and cultural heritage of Indigenous communities across the Arctic, yet the effects of Indigenous hunting on beluga whales remain unknown. Here, we integrate paleogenomics, genetic simulations, and stable C and N isotope analysis to investigate 700 y of beluga subsistence hunting in the Mackenzie Delta area of northwestern Canada. Genetic identification of the zooarchaeological remains, which is based on radiocarbon dating, span three time periods (1290 to 1440 CE; 1450 to 1650 CE; 1800 to 1870 CE), indicates shifts across time in the sex ratio of the harvested belugas.

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The Seychelles magpie-robin's (SMR) five island populations exhibit some of the lowest recorded levels of genetic diversity among endangered birds, and high levels of inbreeding. These populations collapsed during the 20th century, and the species was listed as Critically Endangered in the IUCN Red List in 1994. An assisted translocation-for-recovery program initiated in the 1990s increased the number of mature individuals, resulting in its downlisting to Endangered in 2005.

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Extant Old World camels (genus Camelus) contributed to the economic and cultural exchanges between the East and West for thousands of years. Although many remains have been unearthed, we know neither whether the prevalent hybridization observed between extant Camelus species also occurred between extinct lineages and the ancestors of extant Camelus species nor why some populations became extinct while others survived. To investigate these questions, we generated paleogenomic and stable isotope data from an extinct two-humped camel species, Camelus knoblochi.

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Low genomic diversity is generally indicative of small population size and is considered detrimental by decreasing long-term adaptability. Moreover, small population size may promote gene flow with congeners and outbreeding depression. Here, we examine the connection between habitat availability, effective population size (N), and extinction by generating a 40× nuclear genome from the extinct blue antelope (Hippotragus leucophaeus).

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Due to their limited dispersal ability, fossorial species with predominantly belowground activity usually show increased levels of population subdivision across relatively small spatial scales. This may be exacerbated in harsh mountain ecosystems, where landscape geomorphology limits species' dispersal ability and leads to small effective population sizes, making species relatively vulnerable to environmental change. To better understand the environmental drivers of species' population subdivision in remote mountain ecosystems, particularly in understudied high-elevation systems in Africa, we studied the giant root-rat (Tachyoryctes macrocephalus), a fossorial rodent confined to the afro-alpine ecosystem of the Bale Mountains in Ethiopia.

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The brown bear () is one of the survivors of the Late Quaternary megafauna extinctions. However, despite being widely distributed across the Holarctic, brown bears have experienced extensive range reductions, and even extirpations in some geographical regions. Previous research efforts using genetic data have provided valuable insights into their evolutionary history.

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The Arctic is among the most climatically sensitive environments on Earth, and the disappearance of multiyear sea ice in the Arctic Ocean is predicted within decades. As apex predators, polar bears are sentinel species for addressing the impact of environmental variability on Arctic marine ecosystems. By integrating genomics, isotopic analysis, morphometrics, and ecological modeling, we investigate how Holocene environmental changes affected polar bears around Greenland.

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Background: Woolly rhinoceros (Coelodonta antiquitatis) is a typical indicator of cold-stage climate that was widely distributed in Northern Hemisphere during the Middle-Late Pleistocene. Although a plethora of fossils have been excavated from Northern China, their phylogenetic status, intraspecific diversity and phylogeographical structure are still vague.

Results: In the present study, we generated four mitogenomes from Late Pleistocene woolly rhinoceros in Northern China and compared them with published data.

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Article Synopsis
  • The black rhinoceros is critically endangered, with its numbers drastically reduced due to hunting and poaching, particularly in the late 20th century.
  • Researchers conducted genomic studies on 63 historical black rhinoceros specimens to identify six major historic populations and their subpopulations, revealing significant genetic structure influenced by geographic barriers.
  • Findings from this genetic analysis provide insights for developing urgent management strategies aimed at conserving the remaining diversity of black rhinoceros populations.
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The impact of post-divergence gene flow in speciation has been documented across a range of taxa in recent years, and may have been especially widespread in highly mobile, wide-ranging marine species, such as cetaceans. Here, we studied individual genomes from nine species across the three families of the toothed whale superfamily Delphinoidea (Delphinidae, Phocoenidae and Monodontidae). To investigate the role of post-divergence gene flow in the speciation process, we used a multifaceted approach, including (i) phylogenomics, (ii) the distribution of shared derived alleles and (iii) demographic inference.

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Article Synopsis
  • The blue antelope is the only large African mammal known to have gone extinct in recent history, with no complete genomic data previously available due to misidentifications of museum specimens.
  • Researchers successfully obtained two draft genomes: one from a historical specimen about 200 years old and another from a fossil dating back around 9,800 years, which is currently the oldest paleogenome known from Africa.
  • Genetic analyses reveal that blue and sable antelope are closely related, with evidence of past gene flow, while indicating low genetic diversity in blue antelope, which, along with fossil findings, points to significant population decline before the species' extinction, likely exacerbated by human impact during the colonial era.
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Kiwi are a unique and emblematic group of birds endemic to New Zealand. Deep-time evolutionary relationships among the five extant kiwi species have been difficult to resolve, in part due to the absence of pre-Quaternary fossils to inform speciation events. Here, we utilise single representative nuclear genomes of all five extant kiwi species (great spotted kiwi, little spotted kiwi, Okarito brown kiwi, North Island brown kiwi, and southern brown kiwi) and investigate their evolutionary histories with phylogenomic, genetic diversity, and deep-time (past million years) demographic analyses.

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Accurate sex identification is crucial for elucidating the biology of a species. In the absence of directly observable sexual characteristics, sex identification of wild fauna can be challenging, if not impossible. Molecular sexing offers a powerful alternative to morphological sexing approaches.

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Tigers () are flagship big cats and attract extensive public attention due to their charismatic features and endangered status. Despite this, little is known about their prehistoric lineages and detailed evolutionary histories. Through palaeogenomic analyses, we identified a Pleistocene tiger from northeastern China, dated to beyond the limits of radiocarbon dating (greater than 43 500 years ago).

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Article Synopsis
  • The grey wolf was the first animal to be domesticated into dogs and lived through the last Ice Age when many other animals went extinct.
  • Scientists studied 72 ancient wolf genomes from different places to understand how wolves were connected and how they evolved over 100,000 years.
  • They found that dogs are more closely related to ancient wolves from eastern Asia, but some dogs in the Near East and Africa share ancestors with different wolves, which means there might have been several ways dogs were domesticated.
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The East Greenland-Svalbard-Barents Sea (EGSB) bowhead whale stock (Balaena mysticetus) was hunted to near extinction and remains Endangered on the International Union of Conservation of Nature Red List. The intense, temporally extensive hunting pressure may have left the population vulnerable to other perturbations, such as environmental change. However, the lack of genomic baseline data renders it difficult to evaluate the impacts of various potential stressors on this stock.

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The evolutionary relationships of Felidae during their Early-Middle Miocene radiation is contentious. Although the early common ancestors have been subsumed under the grade-group this group is thought to be paraphyletic, including the early ancestors of both modern cats and extinct sabretooths. Here, we sequenced a draft nuclear genome of dated to 13,182 ± 90 cal BP, making this the oldest palaeogenome from South America to date, a region known to be problematic for ancient DNA preservation.

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The roe deer ( spp.) has been present in China since the early Pleistocene. Despite abundant fossils available for detailed morphological analyses, little is known about the phylogenetic relationships of the fossil individuals to contemporary roe deer.

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Since the 19th century, the addax () has lost approximately 99% of its former range. Along with its close relatives, the blue antelope () and the scimitar-horned oryx (), the addax may be the third large African mammal species to go extinct in the wild in recent times. Despite this, the evolutionary history of this critically endangered species remains virtually unknown.

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Only five species of the once-diverse Rhinocerotidae remain, making the reconstruction of their evolutionary history a challenge to biologists since Darwin. We sequenced genomes from five rhinoceros species (three extinct and two living), which we compared to existing data from the remaining three living species and a range of outgroups. We identify an early divergence between extant African and Eurasian lineages, resolving a key debate regarding the phylogeny of extant rhinoceroses.

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Article Synopsis
  • The Hyaenidae family, once diverse during the Miocene, has narrowed down to four species: spotted, striped, and brown hyenas, and the aardwolf, with a focus on understanding their evolutionary relationships and genomic traits related to scavenging and insectivory.
  • The study reveals phylogenetic discordance, gene flow between aardwolves and brown/striped hyenas, and significant genetic selections linked to adaptations for feeding on carrion and termites.
  • Findings indicate low genetic diversity in brown and striped hyenas over the past 2 million years, while spotted hyenas and aardwolves show higher genetic diversity, highlighting the influence of ecological specialization on evolutionary history.
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Synopsis of recent research by authors named "Michael V Westbury"

  • Michael V Westbury's recent research focuses on the genetic adaptations and evolutionary histories of various Arctic and endangered species, revealing insights into how environmental changes and human activities influence genetic diversity and population dynamics.
  • His studies on polar bears and beluga whales illustrate the impacts of climate and Indigenous hunting practices on these species, emphasizing the importance of genetic diversity for their survival and conservation.
  • Additionally, Westbury's work on the genomic analysis of extinct and endangered species, such as the blue antelope and the Seychelles magpie-robin, investigates the consequences of low population sizes and habitat loss, aiming to inform conservation strategies and highlight the complex relationships between genetics, adaptation, and extinction risks.