Late Pleistocene polar bear genomes reveal the timing of allele fixation in key genes associated with Arctic adaptation.

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.

Elucidating the sustainability of 700 y of Inuvialuit beluga whale hunting in the Mackenzie River Delta, Northwest Territories, Canada.

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.

When birds of a feather flock together: Severe genomic erosion and the implications for genetic rescue in an endangered island passerine.

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.

Camelus knoblochi genome reveals the complex evolutionary history of Old World camels.

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.

Colonial-driven extinction of the blue antelope despite genomic adaptation to low population size.

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).

Topographic barriers drive the pronounced genetic subdivision of a range-limited fossorial rodent.

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.

The origins and diversification of Holarctic brown bear populations inferred from genomes of past and present populations.

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.

Impact of Holocene environmental change on the evolutionary ecology of an Arctic top predator.

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.

Ancient mitogenomes reveal a high maternal genetic diversity of Pleistocene woolly rhinoceros in Northern China.

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.

A genomic assessment of the marine-speciation paradox within the toothed whale superfamily Delphinoidea.

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.

Genomic insights into the evolutionary relationships and demographic history of kiwi.

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.

How low can you go? Introducing SeXY: sex identification from low-quantity sequencing data despite lacking assembled sex chromosomes.

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.

An extinct and deeply divergent tiger lineage from northeastern China recognized through palaeogenomics.

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).

High genomic diversity in the endangered East Greenland Svalbard Barents Sea stock of bowhead whales (Balaena mysticetus).

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.

A genomic exploration of the early evolution of extant cats and their sabre-toothed relatives.

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.

Ancient Mitogenomes Suggest Stable Mitochondrial Clades of the Siberian Roe Deer.

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.

Diversity and Paleodemography of the Addax (), a Saharan Antelope on the Verge of Extinction.

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.

Ancient and modern genomes unravel the evolutionary history of the rhinoceros family.

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.

Southern introgression increases adaptive immune gene variability in northern range margin populations of Fire-bellied toad.

Northern range margin populations of the European fire-bellied toad () have rapidly declined during recent decades. Extensive agricultural land use has fragmented the landscape, leading to habitat disruption and loss, as well as eutrophication of ponds. In Northern Germany (Schleswig-Holstein) and Southern Sweden (Skåne), this population decline resulted in decreased gene flow from surrounding populations, low genetic diversity, and a putative reduction in adaptive potential, leaving populations vulnerable to future environmental and climatic changes.

Genomic consequences of human-mediated translocations in margin populations of an endangered amphibian.

Due to their isolated and often fragmented nature, range margin populations are especially vulnerable to rapid environmental change. To maintain genetic diversity and adaptive potential, gene flow from disjunct populations might therefore be crucial to their survival. Translocations are often proposed as a mitigation strategy to increase genetic diversity in threatened populations.