Maintenance Of Genetic Diversity Research Articles

Reasons to move far away: studying the drivers of Carpetania matritensis (Hormogastridae: Crassiclitelatta) dispersal behaviour

Dispersal is a crucial process for animal populations as it allows the colonisation of new habitats and the maintenance of genetic diversity. However, it has not been studied enough for soil fauna, which is the basis for a wide variety of ecosystem services. Therefore, the study of their dispersal and the factors that trigger this behaviour is a relevant area of knowledge for the maintenance of the services they provide. For this work, Carpetania matritensis, an endogeic earthworm species endemic to the central Iberian Peninsula, has been used as a model to study the effect of habitat quality and conspecific density on dispersal and exploratory behaviour. The experiment was carried out in horizontal mesocosms divided into three sectors of the same dimensions: an inoculation section (left), a crossing section (centre) and a target sector (right). Those sectors were occupied by soil, a favourable habitat for earthworms, or sand, which represents an unsuitable habitat for earthworms and a physical barrier for their displacement. Earthworms were inoculated at two different densities (2 and 6 individuals per mesocosm; 848.86 and 2546.58 individuals/m3 respectively) and at two experimental durations (4 and 8 days) for each of the three different experimental treatments (unsuitable-unsuitable-suitable (U-U-S), suitable-unsuitable-suitable (S-U-S) and suitable-suitable-suitable (S-S-S), depending on the habitat type filling the inoculation, crossing and target section respectively). The results showed a large effect of treatment on the dispersal rate, being higher when earthworms were inoculated in an adverse environment, establishing habitat quality as a driver of the species’ dispersal behaviour. No significant effects of conspecific density, experimental duration or its interactions were found. Further studies are needed to clarify the species dispersal behaviour with a view to its conservation.

Polygenic signals of sex differences in selection in humans from the UK Biobank.

Sex differences in the fitness effects of genetic variants can influence the rate of adaptation and the maintenance of genetic variation. For example, "sexually antagonistic" (SA) variants, which are beneficial for one sex and harmful for the other, can both constrain adaptation and increase genetic variability for fitness components such as survival, fertility, and disease susceptibility. However, detecting variants with sex-differential fitness effects is difficult, requiring genome sequences and fitness measurements from large numbers of individuals. Here, we develop new theory for studying sex-differential selection across a complete life cycle and test our models with genotypic and reproductive success data from approximately 250,000 UK Biobank individuals. We uncover polygenic signals of sex-differential selection affecting survival, reproductive success, and overall fitness, with signals of sex-differential reproductive selection reflecting a combination of SA polymorphisms and sexually concordant polymorphisms in which the strength of selection differs between the sexes. Moreover, these signals hold up to rigorous controls that minimise the contributions of potential confounders, including sequence mapping errors, population structure, and ascertainment bias. Functional analyses reveal that sex-differentiated sites are enriched in phenotype-altering genomic regions, including coding regions and loci affecting a range of quantitative traits. Population genetic analyses show that sex-differentiated sites exhibit evolutionary histories dominated by genetic drift and/or transient balancing selection, but not long-term balancing selection, which is consistent with theoretical predictions of effectively weak SA balancing selection in historically small populations. Overall, our results are consistent with polygenic sex-differential-including SA-selection in humans. Evidence for sex-differential selection is particularly strong for variants affecting reproductive success, in which the potential contributions of nonrandom sampling to signals of sex differentiation can be excluded.

Genetic Analyses Reveal High Connectivity among Populations of the Honduran White Bat Ectophylla alba in the Caribbean Lowlands of Central Eastern Costa Rica

Vagility, ecological requirements, and forest patches can all influence gene flow among populations. These aspects are critical for the maintenance of genetic diversity in populations. Ectophylla alba is a fruit bat belonging to the family Phyllostomidae with specialized feeding and habitat requirements. Studies examining population genetics in this specialist bat are lacking. In this study, ten microsatellite loci were used to evaluate the current genetic structure of this bat species. Six localities in Costa Rica were evaluated. These localities are included in a landscape with remnants of lowland forests surrounded by cattle pastures, plantations, urban areas, and roads. Our results suggest a genetic population with moderate genetic diversity that was observed at most studied loci, with a statistically non-significant difference between the observed and expected heterozygosity. Most of the genetic variation was observed within rather than among sampled populations. The Mantel test showed a non-significant correlation between genetic diversity and geographic distance. These results suggest that E. alba populations have not shown an effect of habitat fragmentation in the studied area. We argue that the increase of forest patches is too recent to alter genetic diversity among sampled localities. Current migration among populations appears to be high enough to balance allele frequencies among localities.

The advantage of sex: Reinserting fluctuating selection in the pluralist approach.

The advantage of sex, and its fixation in some clades and species all over the eukaryote tree of life, is considered an evolutionary enigma, especially regarding its assumed two-fold cost. Several likely hypotheses have been proposed such as (1) a better response to the negative frequency-dependent selection imposed by the “Red Queen” hypothesis; (2) the competition between siblings induced by the Tangled Bank hypothesis; (3) the existence of genetic and of (4) ecological factors that can diminish the cost of sex to less than the standard assumed two-fold; and (5) a better maintenance of genetic diversity and its resulting phenotypic variation, providing a selective advantage in randomly fluctuating environments. While these hypotheses have mostly been studied separately, they can also act simultaneously. This was advocated by several studies which presented a pluralist point of view. Only three among the five causes cited above were considered yet in such a framework: the Red Queen hypothesis, the Tangled Bank and the genetic factors lowering the cost of sex. We thus simulated the evolution of a finite mutating population undergoing negative frequency-dependent selection on phenotypes and a two-fold (or less) cost of sexuality, experiencing randomly fluctuating selection along generations. The individuals inherited their reproductive modes, either clonal or sexual. We found that exclusive sexuality begins to fix in populations exposed to environmental variation that exceeds the width of one ecological niche (twice the standard deviation of a Gaussian response to environment). This threshold was lowered by increasing negative frequency-dependent selection and when reducing the two-fold cost of sex. It contributes advocating that the different processes involved in a short-term advantage of sex and recombination can act in combination to favor the fixation of sexual reproduction in populations.

Elevated inbreeding in Heliconia tortuosa is determined by tropical forest stand age, isolation and loss of hummingbird functional diversity.

Forest conversion and habitat loss are major threats to biological diversity. Forest regeneration can mitigate the negative effects of old-growth forest loss on species diversity, but less is known about the extent to which forest loss reduces genetic diversity in remnant populations and whether secondary forests play a role in the maintenance of genetic diversity. We quantified genetic diversity in a tropical hummingbird-pollinated understorey herb, Heliconia tortuosa, across a landscape mosaic of primary and secondary forest regrowth. Using microsatellite genotypes from >850 adult and juvenile plants within 33 forest patches and extensive bird surveys, we examined the effect of contemporary and historical landscape features including forest age (primary vs. secondary forest), stand isolation and pollinator assemblages on genetic diversity and levels of inbreeding in H. tortuosa. We found that inbreeding was up to three times higher in secondary forest, and this effect was amplified with reductions in primary forest in the surrounding landscape through reduced observed heterozygosity in isolated fragments. Inbreeding in forest patches was negatively correlated with the local frequency of specialist long-distance foraging traplining hummingbirds. Traplining hummingbirds therefore appear to facilitate mating among unrelated plants-an inference we tested using empirically parameterized simulations. Higher levels of inbreeding in H. tortuosa are therefore associated with reduced functional diversity of hummingbirds in secondary forests and forest patches isolated from primary forests. Our findings suggest a cryptic consequence of primary forest loss and secondary forest regeneration through the disruption of mutualistic interactions resulting in the erosion of genetic diversity in a common understorey plant.

Gene Flow and Recruitment Patterns among Disjunct Populations of Allocasuarina verticillata (Lam.) L.A.S. Johnson

Allocasuarina verticillata (Lam.) L.A.S. Johnson is a widespread species in south-eastern Australia providing vegetation cover, protecting fragile soils and providing food for birds. Understanding the effects of gene flow on the recruitment patterns, genetic differentiation and structure of fragmented populations provides fundamental guidelines to underpin plant conservation strategies and activities. In this study, four spatially disjunct populations of A. verticillata were sampled to explore the effects of population size, reproductive patterns and pollen and seed dispersal on among-population genetic diversity, genetic differentiation and structure, using field survey and microsatellite marker techniques. It was found that stands of A. verticillata were predominantly sexually reproductive, but asexual reproduction through root suckering was an additional mode of reproduction. The reproductive success of A. verticillata is positively correlated with the effective population size rather than actual population size. The reduction in effective population size and increment of spatial isolation resulted in lower genetic diversity and higher inbreeding coefficient of progenies. Moderate pairwise genetic differentiation and weak genetic structure were identified. The results suggest that exogenous, wind-mediated pollen flow provides some maintenance of genetic diversity in the isolated stands. Seed dispersal appears mainly to be over short distances (i.e., within populations), but the infrequent transport of seeds between disjunct locations cannot be ruled out as another factor that may help maintain genetic diversity.

The roles of balancing selection and recombination in the evolution of rattlesnake venom.

The origin of snake venom involved duplication and recruitment of non-venom genes into venom systems. Several studies have predicted that directional positive selection has governed this process. Venom composition varies substantially across snake species and venom phenotypes are locally adapted to prey, leading to coevolutionary interactions between predator and prey. Venom origins and contemporary snake venom evolution may therefore be driven by fundamentally different selection regimes, yet investigations of population-level patterns of selection have been limited. Here, we use whole-genome data from 68 rattlesnakes to test hypotheses about the factors that drive genomic diversity and differentiation in major venom gene regions. We show that selection has resulted in long-term maintenance of genetic diversity within and between species in multiple venom gene families. Our findings are inconsistent with a dominant role of directional positive selection and instead support a role of long-term balancing selection in shaping venom evolution. We also detect rapid decay of linkage disequilibrium due to high recombination rates in venom regions, suggesting that venom genes have reduced selective interference with nearby loci, including other venom paralogues. Our results provide an example of long-term balancing selection that drives trans-species polymorphism and help to explain how snake venom keeps pace with prey resistance.

Evolution of toxins as a public good in phytoplankton.

Toxic phytoplankton blooms have increased in many waterbodies worldwide with well-known negative impacts on human health, fisheries and ecosystems. However, why and how phytoplankton evolved toxin production is still a puzzling question, given that the producer that pays the costs often shares the benefit with other competing algae and thus provides toxins as a 'public good' (e.g. damaging a common competitor or predator). Furthermore, blooming phytoplankton species often show a high intraspecific variation in toxicity and we lack an understanding of what drives the dynamics of coexisting toxic and non-toxic genotypes. Here, by using an individual-based two-dimensional model, we show that small-scale patchiness of phytoplankton strains caused by demography can explain toxin evolution in phytoplankton with low motility and the maintenance of genetic diversity within their blooms. This patchiness vanishes for phytoplankton with high diffusive motility, suggesting different evolutionary pathways for different phytoplankton groups. In conclusion, our study reveals that small-scale spatial heterogeneity, generated by cell division and counteracted by diffusive cell motility and turbulence, can crucially affect toxin evolution and eco-evolutionary dynamics in toxic phytoplankton species. This contributes to a better understanding of conditions favouring toxin production and the evolution of public goods in asexually reproducing organisms in general.

A new test suggests hundreds of amino acid polymorphisms in humans are subject to balancing selection.

The role that balancing selection plays in the maintenance of genetic diversity remains unresolved. Here, we introduce a new test, based on the McDonald-Kreitman test, in which the number of polymorphisms that are shared between populations is contrasted to those that are private at selected and neutral sites. We show that this simple test is robust to a variety of demographic changes, and that it can also give a direct estimate of the number of shared polymorphisms that are directly maintained by balancing selection. We apply our method to population genomic data from humans and provide some evidence that hundreds of nonsynonymous polymorphisms are subject to balancing selection.

Hybridization and low genetic diversity in the endangered Alabama red-bellied turtle (Pseudemys alabamensis).

Pseudemys alabamensis is one of the most endangered freshwater turtle species in the United States due to its restricted geographic distribution in coastal Alabama and Mississippi. Populations of P. alabamensis are geographically isolated from one another by land and saltwater, which could act as barriers to gene flow. It is currently unknown how differentiated these populations are from one another and whether they have experienced reductions in population size. Previous work found morphological differences between Alabama and Mississippi populations, suggesting that they may be evolutionarily distinct. Other Pseudemys turtles such as P. concinna and P. floridana occur naturally within the same geographic area as P. alabamensis and are known to hybridize with each other. These more abundant species could threaten the unique genetic identity of P. alabamensis through introgression. In order to evaluate the endangered status of P. alabamensis and the level of hybridization with other species, we used mitochondrial and nuclear microsatellite markers to assess genetic variation within and among populations of P. alabamensis throughout its range and estimate admixture with co‐occurring Pseudemys species. In P. alabamensis, we found no variation in mitochondrial DNA and an excess of homozygosity in microsatellite data. Our results show genetic differentiation between Alabama and Mississippi populations of P. alabamensis, and low estimated breeding sizes and signs of inbreeding for two populations (Fowl River, Alabama and Biloxi, Mississippi). We also found evidence of admixture between P. alabamensis and P. concinna/P. floridana. Based on our results, P. alabamensis is highly endangered throughout its range and threatened by both low population sizes and hybridization. In order to improve the species’ chances of survival, focus should be placed on habitat preservation, maintenance of genetic diversity within both the Mississippi and Alabama populations, and routine population‐monitoring activities such as nest surveillance and estimates of recruitment.

Linking genetic diversity and species diversity through plant-soil feedback.

Genetic diversity and species diversity are typically studied in isolation despite theory showing they likely influence one another. Here, we used simplified communities of one or two populations of one or two species to test whether linkages between genetic and species diversity can be mediated by interactions between plants and their soil microbiota, or microbe-mediated plant-soil feedback (PSF). Interspecific PSF promotes the maintenance of species diversity when plants grow better with heterospecific soil microbes than with conspecific microbes. Similarly, intraspecific PSF promotes the maintenance of genetic diversity when plants grow better with heterogenotypic than with congenotypic microbes. In a two-phase greenhouse experiment, we conditioned the soil microbial community with pairs of plants that were either two individuals of the same species (lower species diversity) or one individual of each of two species (higher species diversity), and with pairs of plants that were either two individuals from the same population (lower genetic diversity) or one individual from each of two populations (higher genetic diversity). We then tested the effects of these microbial communities on plant growth in a second phase. We found that higher genetic diversity reduced the ability of interspecific PSF to promote plant species diversity, and for one of our two study species, higher species diversity reduced the ability of intraspecific PSF to promote plant genetic diversity. If these patterns occur in more diverse communities, then our results suggest that PSF may dampen the negative effects of diversity loss by promoting diversity at other levels of biological organization.

Maintenance of Genetic Diversity of Black Sea Bream despite Unmonitored and Large-Scale Hatchery Releases.

Simple SummaryStock enhancement aggressively replenishes depleted wild finfish populations. However, stock enhancement of black sea bream in Taiwan with complex genetic sources, especially when successful, maintains genetic diversity but dramatically changes the genetic structure within and among wild populations.Stock enhancement, used for replenishing depleted wild finfish populations, is an aggressive approach. Stock enhancement projects in Taiwan involve black sea bream (Acanthopagrus schlegelii), a major commercial species. During 2004–2015, even management agencies conducted stock enhancement projects, leading to numerous private releases that have not been recorded. Stock enhancement by a private hatchery without accurate genetic records may lead to a genetic structure change in wild populations. Using allele frequencies at nine microsatellite loci, we studied the genetic effects of stock enhancement in 19 samples collected from populations in the hatcheries and the wild. In 458 individuals from nine hatchery samples, most populations showed weak but significant genetic differences and complex clusters in structure analysis, indicating dramatic stock change within and among hatcheries. The 10 wild populations (n = 773) also had a complex genetic composition and were genetically different among sampling sites and times. However, a simple and clear cluster in structure analysis was found for only one sampling site, which had no release history. Thus, stock enhancement with complex genetic sources helps maintain genetic diversity but dramatically changes the genetic structure within and among wild populations, especially when stock enhancement is successful.

Pollen morphology, meiotic index and pollen viability in individuals of Vochysia divergens Pohl. native to the Amazon and the Pantanal

Vochysia divergens Pohl. is a tree species used in folk medicine, landscaping and reforestation. Its occurrence is recorded in the Amazon, Pantanal and Cerrado biomes and, despite these uses and its wide distribution, studies regarding its reproductive aspects are nonexistent. Thus, this research aimed to study the morphology of the pollen of V. divergens and evaluate the pollen viability and its meiotic index, as well as compare these descriptors in two natural populations, those of the Amazon and the Pantanal. To characterize the morphology, pollen grains were subjected to acetolysis and subsequently photographed, measured and classified. The meiotic index (MI) was estimated by counting post-meiotic products. Pollen viability was evaluated via colorimetric testing and in vitro germination. Pollen grains do not differ in morphology between populations and are classified as: large, 3-colporate, isopolar, subprolate, with a small and exine polar area that has a pattern of ornamentation that is perforated in the polar region. Via the colorimetric testing, the MI and the pollen viability were greater than 95% and only the MI differed between populations. Pollen germination was low and it was found that the presence of boric acid and absence of agar positively influence germination. The pollens of V. divergens have starch and lipids as a reserve substance. It can therefore be concluded that the species has reproductive stability, which is important in the effectiveness of fertilization and generation of new individuals for the formation of new generations, thus continuing the processes of forest restoration and maintenance of genetic variability. The information obtained regarding the pollen morphology can be used to support taxonomic, paleoclimatic and paleovegetational studies.

Conservation prioritization based on past cascading climatic effects on genetic diversity and population size dynamics: Insights from a temperate tree species

AbstractAimThe biogeographic history affects adaptive evolution by altering the pattern of genetic variation and provides the background upon which other evolutionary processes are operating. Assessment of the consequence of such eco‐evolutionary interactions is crucial to population's genetic diversity maintenance. Yet, considering how biogeographic and multiple evolutionary processes interact in complex environments to alter genetic diversity in conservation planning remains unresolved.LocationThe Pacific Northwest.MethodsHerein I document the impact of geographic landscapes and past climatic fluctuations on the evolutionary processes that drive population divergence of Populus trichocarpa by assembling genomic, climatic and species occurrence data.ResultsBased on inferences of demographic history of the species and tests for niche divergence, results show that the British Columbia (BC)‐North and BC‐South populations are ancestral and subject to more recent bottlenecks than the Oregon population. Consistently, ecological niche modelling illustrates that compared to the Last Glacial Maximum (~21 Ka), the present niche suitability of the BC‐North and ‐South populations is overall marginally inferior to that of the Oregon population. However, genomic analysis demonstrates that the Oregon harbours the lowest genetic diversity, possibly due to an extended bottleneck experienced by the population. Model prediction indicates that in the 2050s, the impact of climate change is minor compared to the niche suitability of the species as a whole, but climate change will likely result in considerable genetic shifts over two generations especially in the Oregon and BC‐South populations, which will attenuate along a northward gradient.Main conclusionsThis study underpins the long‐lasting impact of demographic histories and natural selection on genetic diversity, rather than highlighting the consequence of recent demographic events (e.g. bottleneck in the Holocene epoch; ~12 Ka) potentially cascading to eroding genetic diversity and yielding conservation urgency.

Utilizing Genomic Selection for Wheat Population Development and Improvement

Wheat (Triticum aestivum L.) breeding programs can take over a decade to release a new variety. However, new methods of selection, such as genomic selection (GS), must be integrated to decrease the time it takes to release new varieties to meet the demand of a growing population. The implementation of GS into breeding programs is still being explored, with many studies showing its potential to change wheat breeding through achieving higher genetic gain. In this review, we explore the integration of GS for a wheat breeding program by redesigning the traditional breeding pipeline to implement GS. We propose implementing a two-part breeding strategy by differentiating between population improvement and product development. The implementation of GS in the product development pipeline can be integrated into most stages and can predict within and across breeding cycles. Additionally, we explore optimizing the population improvement strategy through GS recurrent selection schemes to reduce crossing cycle time and significantly increase genetic gain. The recurrent selection schemes can be optimized for parental selection, maintenance of genetic variation, and optimal cross-prediction. Overall, we outline the ability to increase the genetic gain of a breeding program by implementing GS and a two-part breeding strategy.

The role of free-flowing tributary rivers in the maintenance of genetic diversity of a migratory fish species living in a river fragmented by dams

The role of free-flowing tributary rivers in the maintenance of genetic diversity of a migratory fish species living in a river fragmented by dams

Genetic diversity and mate selection in a reintroduced population of gray wolves

The genetic composition of an individual can markedly affect its survival, reproduction, and ultimately fitness. As some wildlife populations become smaller, conserving genetic diversity will be a conservation challenge. Many imperiled species are already supported through population augmentation efforts and we often do not know if or how genetic diversity is maintained in translocated species. As a case study for understanding the maintenance of genetic diversity in augmented populations, I wanted to know if genetic diversity (i.e., observed heterozygosity) remained high in a population of gray wolves in the Rocky Mountains of the U.S. > 20 years after reintroduction. Additionally, I wanted to know if a potential mechanism for such diversity was individuals with below average genetic diversity choosing mates with above average diversity. I also asked whether there was a preference for mating with unrelated individuals. Finally, I hypothesized that mated pairs with above average heterozygosity would have increased survival of young. Ultimately, I found that females with below average heterozygosity did not choose mates with above average heterozygosity and wolves chose mates randomly with respect to genetic relatedness. Pup survival was not higher for mated pairs with above average heterozygosity in my models. The dominant variables predicting pup survival were harvest rate during their first year of life and years pairs were mated. Ultimately, genetic diversity was relatively unchanged > 20 years after reintroduction. The mechanism for maintaining such diversity does not appear related to individuals preferentially choosing more genetically diverse mates. Inbreeding avoidance, however, appears to be at least one mechanism maintaining genetic diversity in this population.

Detecting Structural Variants and Associated Gene Presence-Absence Variation Phenomena in the Genomes of Marine Organisms.

As complete genomes become easier to attain, even from previously difficult-to-sequence species, and as genomic resequencing becomes more routine, it is becoming obvious that genomic structural variation is more widespread than originally thought and plays an important role in maintaining genetic variation in populations. Structural variants (SVs) and associated gene presence-absence variation (PAV) can be important players in local adaptation, allowing the maintenance of genetic variation and taking part in other evolutionarily relevant phenomena. While recent studies have highlighted the importance of structural variation in Mollusca, the prevalence of this phenomenon in the broader context of marine organisms remains to be fully investigated.Here, we describe a straightforward and broadly applicable method for the identification of SVs in fully assembled diploid genomes, leveraging the same reads used for assembly. We also explain a gene PAV analysis protocol, which could be broadly applied to any species with a fully sequenced reference genome available. Although the strength of these approaches have been tested and proven in marine invertebrates, which tend to have high levels of heterozygosity, possibly due to their lifestyle traits, they are also applicable to other species across the tree of life, providing a ready means to begin investigations into this potentially widespread phenomena.

Collection of rare woody plants species in M. M. Gryshko National Botanical garden of NAS of Ukraine

Preservation of rare plant species in nature (in situ) is an effective method of protection and maintenance of genetic diversity, but the preservation of plants ex situ is a necessary complement in modern conditions. In the M.M. Gry- shko National Botanical Garden of NAS of Ukraine to preserve and replenish the collections of plants listed in the Red Book of Ukraine and other protection lists is defined as one of the strategic tasks of the institution. In total, the institution has collected 190 species of plants protected by the law “On the Red Book of Ukraine”.The collection of rare and en- dangered tree and shrub plants is represented by 21 species, among which: Vulnerable — 9 (43%), Rare — 7 (33%), Endangered — 4 (14%), Not Evaluated — 1 (5%). This number of species and their representativeness is not suflcient for their successful protection ex situ. There is great prospects for expanding the collection to preserve species and spread the plants to other botanical gardens and arboretums of Ukraine.

Genotyping-in-Thousands by sequencing of archival fish scales reveals maintenance of genetic variation following a severe demographic contraction in kokanee salmon

Historical DNA analysis of archival samples has added new dimensions to population genetic studies, enabling spatiotemporal approaches for reconstructing population history and informing conservation management. Here we tested the efficacy of Genotyping-in-Thousands by sequencing (GT-seq) for collecting targeted single nucleotide polymorphism genotypic data from archival scale samples, and applied this approach to a study of kokanee salmon (Oncorhynchus nerka) in Kluane National Park and Reserve (KNPR; Yukon, Canada) that underwent a severe 12-year population decline followed by a rapid rebound. We genotyped archival scales sampled pre-crash and contemporary fin clips collected post-crash, revealing high coverage (> 90% average genotyping across all individuals) and low genotyping error (< 0.01% within-libraries, 0.60% among-libraries) despite the relatively poor quality of recovered DNA. We observed slight decreases in expected heterozygosity, allelic diversity, and effective population size post-crash, but none were significant, suggesting genetic diversity was retained despite the severe demographic contraction. Genotypic data also revealed the genetic distinctiveness of a now extirpated population just outside of KNPR, revealing biodiversity loss at the northern edge of the species distribution. More broadly, we demonstrated GT-seq as a valuable tool for collecting genome-wide data from archival samples to address basic questions in ecology and evolution, and inform applied research in wildlife conservation and fisheries management.