Genetic and morphological differentiation between remnant populations of an endangered species: the case of the Seychelles White-eye

The Seychelles White-eye Zosterops modestus is a critically endangered species that survives in two remnant populations on the islands of Mahé and Conception. Multilocus minisatellite DNA fingerprinting and morphometric measurements were used to assess the levels of variation between these populations. Mahé White-eyes are on average significantly larger than Conception birds, as are males compared to females. The mean level of bandsharing ( c.  60%) indicates low levels of genetic variability within both populations. Bandsharing is significantly lower between populations (32%), suggesting that the two populations are genetically isolated from each other, and that one is not a subsample from the other. Both populations should therefore be considered as equally important genetic reservoirs that deserve to be safeguarded. Although each population appears locally adapted to its particular island environment, such limited differentiation is not considered of major taxonomic significance. Recombining genetic variation by mixing individuals from both populations may be beneficial for the species in view of future island transfers. This illustrates the importance of investigating differentiation between remnant populations of a threatened species to orientate future conservation and management measures.     

Genetics at the verge of extinction: insights from the Iberian lynx

Population viability might become compromised by the loss of genetic diversity and the accumulation of inbreeding resulting from population decline and fragmentation. The Iberian lynx (Lynx pardinus) provides a paradigmatic example of a species at the verge of extinction, and because of the well‐documented and different demographic histories of the two remaining populations (Doñana and Andújar), it provides the opportunity to evaluate the performance of analytical methods commonly applied to recently declined populations. We used mitochondrial sequences and 36 microsatellite markers to evaluate the current genetic status of the species and to assess the genetic signatures of its past history. Mitochondrial diversity was extremely low with only two haplotypes, alternatively fixed in each population. Both remnant populations have low levels of genetic diversity at microsatellite markers, particularly the population from Doñana, and genetic differentiation between the two populations is high. Bayesian coalescent‐based methods suggest an earlier decline starting hundreds of years ago, while heterozygosity excess and M‐ratio tests did not provide conclusive and consistent evidence for recent bottlenecks. Also, a model of gene flow received overwhelming support over a model of pure drift. Results that are in conflict with the known recent demography of the species call for caution in the use of these methods, especially when no information on previous demographic history is available. Overall, our results suggest that current genetic patterns in the Iberian lynx are mainly the result of its recent decline and fragmentation and alerts on possible genetic risks for its persistence. Conservation strategies should explicitly consider this threat and incorporate an integrated genetic management of wild, captive and re‐introduced populations, including genetic restoration through translocations.     

High genetic diversity in the remnant island population of hihi and the genetic consequences of re-introduction

The maintenance of genetic diversity is thought to be fundamental for the conservation of threatened species. It is therefore important to understand how genetic diversity is affected by the re-introduction of threatened species. We use establishment history and genetic data from the remnant and re-introduced populations of a New Zealand endemic bird, the hihi Notiomystis cincta, to understand genetic diversity loss and quantify the genetic effects of re-introduction. Our data do not support any recent bottleneck events in the remnant population. Furthermore, all genetic diversity measures indicate the remnant hihi population has retained high levels of genetic diversity relative to other New Zealand avifauna with similar histories of decline. Genetic diversity (N(A) , alleles per locus, allelic richness, F(IS) and H(S) ) did not significantly decrease in new hihi populations founded through re-introduction when compared to their source populations, except in the Kapiti Island population (allelic richness and H(S) ) which had very slow post-re-introduction population growth. The N(e) /N(c) ratio in the remnant population was high, but decreased in first-level re-introductions, which together with significant genetic differentiation between populations (F(ST) & Fisher's exact tests) suggest that extant populations are diverging as a result of founder effects and drift. Importantly, simulations of future allele loss predict that the number of alleles lost will be higher in populations with a slow population growth, fewer founding individuals and with nonrandom mating. Interestingly, this species has very high levels of extra-pair paternity which may reduce reproductive variance by allowing social and floater males to reproduce a life history trait that together with a large remnant population size may help maintain higher levels of genetic diversity than expected.     

Genetic management of the red squirrel,Sciurus vulgaris: a practical approach to regional conservation

The progressive decline in red squirrel (Sciurus vulgaris) numbers in Wales has led to conservation and reintroduction projects being established on the island of Anglesey. The recovery of the island’s remnant wild population was initially successful, however concern remained over potential loss of genetic diversity resulting from an observed demographic bottleneck. We used mitochondrial DNA (mtDNA) control region sequences and six microsatellite loci to assess current levels of genetic variation in the population. Samples were monomorphic for control region sequences and a historic specimen from the same area carrying a different haplotype demonstrated a loss of mtDNA diversity during the last 20 years. Inclusion of other Welsh haplotypes indicated phylogeographic structure in the region, in contrast to previous UK studies. Genotyping results showed allelic diversity and heterozygosity to be less than 50% of that recorded in other UK populations, with strong evidence for a recent genetic bottleneck. A parallel reintroduction programme on Anglesey included genetic analysis of individuals during the selection of captive breeding pairs. We present analysis of sequence and microsatellite data, and subsequent management decisions taken to maximise diversity in the founder and F1 generations. Population and Habitat Viability Analysis applied to both populations modelled future levels of heterozygosity and allelic diversity. Supplementation of the remnant and reintroduced populations with translocated squirrels was simulated as a potential management tool; results support use of this strategy to reduce loss of diversity and increase survival. The limitations of applying conservation genetic theory within small-scale management projects are discussed.     

Genetic diversity and structure of remnant <Emphasis Type="Italic">Magnolia stellata</Emphasis> populations affected by anthropogenic pressures and a conservation strategy for maintaining their current genetic diversity

Understanding the factors shaping rare species’ current genetic diversity and structure, particularly the impact of recent anthropogenic pressures, is important in order to develop appropriate conservation strategies based on robust predictions. Thus, we have genotyped all 585 surviving individuals of Magnolia stellata from six remnant populations and seven isolated tree sites in northern Mie Prefecture, Japan, using nuclear and chloroplast microsatellites. Three genetic clusters were detected by STRUCTURE analysis, with an oldest divergence time between pairs within 25 generations according to coalescent analysis. We attribute this recent divergence to recent anthropogenic environmental changes. Evidence of only one significant recent migration event between pairs of the six populations was detected, indicating that most of the remnant populations are isolated now. Their future genetic status was predicted using Monte Carlo simulations, under four scenarios. It declined more than twice as rapidly in a scenario assuming variations in fecundity among both female and male parents than in a scenario assuming no fecundity variations, but strongly improved in a scenario including promotion of migrations between adjacent pairs of populations. These predictions indicate that sexual reproduction of the species should be promoted by providing more suitable habitats and migration between populations should be enhanced by restoring remnant isolated tree sites and extinct populations. In addition, all the remnant populations should be conserved because they host current genetic variation that may be important for coping with future climate change, and they could provide important stepping-stones for gene flow.     

中华水韭残存居群的数量性状分化和地方适应性及其对保育遗传复壮策略的提示

 研究残存居群的数量性状分化及其地方适应性有助于了解不同居群对环境的适应性并制定相应的保育策略。本研究采用同园实验,利用随机区 组设计,对中华水韭(Isoetes s inensis)3个居群的9种优势基因型的数量性状进行巢式方差分析,并采用Bayesian方法计算等位酶（F_ST）和 数量性状（Q_ST）的居群分化值。结果表明,在测量的14个数量性状中,有10个性状在居群间有显著性差异,仅有3个性状在居群内有显著性差 异;多重比较表明其中5个性状的平均值均以松阳居群最高,休宁居群最低;建德居群的大孢子囊的性状和植株高度的平均值最高,休宁居群最 低;推测这可能是与奠基者效应、物种间竞争及中华水韭在自然生境下形成的营养生长和生殖生长之间的权衡有关。对居群数量性状分化的QST 值和等位酶分化的FST值分析比较发现,在假设为自交系时有8个性状的Q_ST值均大于F_ST值,表明存在明显的地方适应性,居群间个体的混合存 在潜在的远交衰退的风险,所以不宜采用居群间相互移植个体的方法来进行中华水韭居群的遗传复壮。对休宁和松阳两个居群的保育应采用提 高居群内基因流和改善生境环境的方法,促进居群内的遗传复壮;对建德居群应尽量减少人为干扰,宜建立特定生境的保护小区。     

Genetic Variation in Remnant Populations of the Woolly Spider Monkey (Brachyteles arachnoides)

The muriqui or woolly spider monkey (Brachyteles arachnoids) is an endangered primate endemic to the Atlantic Forest of Brazil, <5% of which remains. The known muriqui population consists of <700 individuals separated into approximately 15 geographically isolated forest fragments. I present data on the distribution of genetic variation within and between two such remnant populations (FE and FBR) and summarize the implications of these results for long-range management of species genetic diversity. Eleven of 32 allozyme loci were polymorphic, representing an overall level of polymorphism of 34.4% and a mean heterozygosity per locus of 11%. Both values are among the highest reported for New World monkeys. Genetic differentiation between the two localities is highly significant (F_ST = 0.413, p < 0.001). Genetic distance between them is an order of magnitude greater than that between other populations of platyrrhine subspecies, but this could be an artifact of the small sample size from FBR. High levels of genetic diversity apparently characteristic of this species persist because (1) fragmentation and size reduction of muriqui populations has occurred very rapidly relative to the muriqui life span—although both polymorphism and heterozygosity were lost between generations in the largest population, the high genetic diversity present in the parent population was still in evidence; and (2) genetic diversity before population fragmentation by human activity was not distributed uniformly throughout the species' historic distribution. Thus, remnant muriqui populations are important genetic reservoirs of alleles that are unique or rare in the species gene pool as a whole. These results emphasize the need for the integration of conservation management efforts throughout the species range.     

Population genetic structure of the blue-fronted Amazon (Amazona aestiva, Psittacidae: Aves) based on nuclear microsatellite loci: implications for conservation

The blue-fronted Amazon (Amazona aestiva) is a widely distributed Neotropical parrot and one of the most captured parrots in nature to supply the illegal trade of wild animals. The objectives of the present study were to analyze the genetic structure of A. aestiva to identify management units and support conservation planning and to verified if A. aestiva populations have undergone a recent bottleneck due to habitat loss and capture for the pet trade. The genetic structure was accessed by analyzing six microsatellite loci in 74 individuals of A. aestiva, including samples from the two subspecies (A. a. aestiva and A. a. xanthopteryx), from five populations: four in Brazil and one in Argentina. A significant genetic differentiation (theta = 0.007, p = 0.005) could be detected only between the most distant populations, Tocantins and Argentina, localized at the northeast and southwest limits of the sample sites, respectively. There was no evidence of inbreeding within or between populations, suggesting random mating among individuals. These results suggest a clinal distribution of genetic variability, as observed for variation in plumage color of the two A. aestiva subspecies. Bottleneck analysis did not show a recent reduction in population size. Thus, for the management and conservation of the species, the populations from Argentina and Tocantins should be considered as different management units, and the other populations from the center of the geographical distribution as another management unit.     

Management units of the endangered herb Primula sieboldii based on microsatellite variation among and within populations throughout Japan

To promote programs for the conservation and restoration of the endangered species Primula sieboldii, we examined genetic variation at eight microsatellite loci among and within 32 remnant wild populations throughout Japan. Total allelic diversity within a population was higher in larger populations, but not so after rarefaction adjustment. The positive relationship between population size and the inbreeding coefficient may suggest that more heterozygous genets tend to survive the habitat contraction possibly because of the higher fitness associated with heterozygosity. By principal coordinate analysis and Bayesian analysis, we detected four genetic groups (Hokkaido, northern Honshu, central Honshu, and western Japan), which could be recognized as management units of P. sieboldii. If supplementation with plants from other populations were planned, it should be conducted among populations which belong to the same management unit and which are likely to represent the same adaptive variation.     

Population boundaries and genetic diversity in the endangered Mariana crow (Corvus kubaryi)

The Mariana crow (Corvus kubaryi) is an endangered species that is restricted to the islands of Guam and Rota in the Mariana archipelago. Predation by the introduced brown tree snake (Boiga irregularis) has decimated bird populations on Guam, and the crow population there is the last wild remnant of the endemic forest avifauna. The population on Guam is critically endangered and, despite intensive management, the population has continued to decline. Additional management options include intermixing the Guam and Rota populations, but such options are best evaluated within a population genetics framework. We used three types of molecular markers to assay genetic variation in the Mariana crow: mitochondrial DNA (mtDNA) sequences, minisatellites and microsatellites. The two populations could be differentiated by mtDNA sequencing and they differed in allele frequencies at nuclear markers. Thus, the populations could be designated as evolutionarily significant units. However, the Guam population is genetically more diverse than the Rota population, and its survival probability if managed separately is very low. All markers did indicate that the two populations are closely related and separated by a shallow genealogical division. Intermixing the populations is justified by two rationales. First, the apparent population differences may result from recent human activities. Second, a greater amount of genetic information may be preserved by joint management. The translocation of birds from Rota to Guam has begun, but strategies that will ensure maintenance of the variation in the Guam population warrant further exploration.     

Translocations maintain genetic diversity and increase connectivity in sea otters,Enhydra lutris

Sea otters, Enhydra lutris, were once abundant along the nearshore areas of the North Pacific. The international maritime fur trade that ended in 1911 left 13 small remnant populations with low genetic diversity. Subsequent translocations into previously occupied habitat resulted in several reintroduced populations along the coast of North America. We sampled sea otters between 2008 and 2011 throughout much of their current range and used 19 nuclear microsatellite markers to evaluate genetic diversity, population structure, and connectivity between remnant and reintroduced populations. Average genetic diversity within populations was similar: observed heterozygosity 0.55 and 0.53, expected heterozygosity 0.56 and 0.52, unbiased expected heterozygosity 0.57 and 0.52, for reintroduced and remnant populations, respectively. Sea otter population structure was greatest between the Northern and Southern sea otters with further structuring in Northern sea otters into Western, Central, and Southeast populations (including the reintroduced populations). Migrant analyses suggest the successful reintroductions and growth of remnant groups have enhanced connectivity and gene flow between populations throughout many of the sampled Northern populations. We recommend that future management actions for the Southern sea otter focus on future reintroductions to fill the gap between the California and Washington populations ultimately restoring gene flow to the isolated California population.     

Population genetic connectivity of an endemic New Zealand passerine after large‐scale local extirpations: a model of re‐colonization potential

Little is known about how a 70% loss of native forests has affected the genetic connectivity of remnant bird populations in New Zealand. We use the common and widely distributed New Zealand Bellbird Anthornis melanura as an indicator species of population connectivity for well‐flighted birds. Using eight microsatellite loci, we identified five main genetic populations in the North Island, South Island, sub‐Antarctic Auckland Islands and two small remnant island populations adjacent to a large region of avian extirpations in northern North Island. Only one remnant island population, on a 30‐year‐old conservation reserve at Tiritiri Matangi, displayed a clear signature of recent genetic bottleneck. The 7% migration rate at Tiritiri Matangi indicates that bottlenecks can be maintained despite habitat rehabilitation, possibly through behavioural barriers to gene flow. Adjacent to the same extirpation zone, Bellbirds on the Poor Knights Islands were found to have low genetic diversity and low re‐colonization potential. Two gaps concordant with deforestation patterns separated the Kapiti Coast of southern North Island from populations to both the north and the south. In summary, we identified linked avian habitats, as well as isolated and inbred populations and suggest that Bellbirds are good re‐colonizers. We emphasize the importance of genetic studies that assess animal dispersal among newly rehabilitated habitat patches.     

Genetic population structure and management units of the endangered Tokyo bitterling, Tanakia tanago (Cyprinidae)

The Tokyo bitterling Tanakia tanago (Cyprinidae) was once found throughout the Kanto Plain, central Japan, but most of their habitats have been lost due to human activities such as urbanization and improvement of paddy fields. Subsequently, conservation efforts, including captive breeding and reintroduction, have been ongoing. However, the genetic relationships among populations of this species including captive and remnant wild populations have been uncertain and thus management units for this species have been unidentified. We examined the population differentiation among 12 populations, including four wild and eight captive populations, and their relative genetic diversities to assist in conservation management decisions. Phylogeographic analyses based on partial mitochondrial cytochrome b gene sequences and microsatellite polymorphisms revealed four geographically associated genetic groups in the populations. Northern Tochigi populations have diverged from other populations (0.77% of d _A ), likely stemming from allopatric fragmentation following a change in the route of the Naka River, which occurred during the middle of the Pleistocene epoch. Microsatellite analysis has revealed that the genetic diversity of each population is generally low, and that most of the populations have experienced genetic bottlenecks. For future in- and ex-situ conservation programs to succeed, the population structure and genetic variability of remnant populations need to be taken into consideration.     

Genetic structure and diversity of the koala population in South Gippsland,Victoria: a remnant population of high conservation significance

In the Australian state of Victoria, the history of koalas and their management has resulted in the homogenisation and reduction of genetic diversity in many contemporary populations. Decreased genetic diversity may reduce a species’ ability to adapt to future environmental pressures such as climate change or disease. The South Gippsland koala population is considered to be unique in Victoria, as it is believed to be a remnant population, not originating from managed populations that have low genetic variation. This study investigated genetic structure and diversity of koalas in South Gippsland, with comparison to other populations in Victoria (French Island/Cape Otway, FI and Raymond Island, RI), New South Wales and south east Queensland. Population analyses were undertaken using both microsatellite genotype and mitochondrial DNA sequence data. Non-invasive sampling of koala scats was used to source koala DNA, allowing 222 South Gippsland koalas to be genotyped. Using nuclear data the South Gippsland koala population was found to be significantly differentiated (D_jost 95% CI SG–RI?=?0.03–0.06 and SG–FI?=?0.08–012) and more diverse (A_R 95% CI SG?=?4.7–5.6, RI?=?3.1–3.3, FI?=?3.0–3.3; p?=?0.001) than other Victorian koala populations, supporting the premise that koalas in the South Gippsland region are part of a remnant population, not derived from translocated island stock. These results were also supported by mitochondrial data where eight haplotypes (Pc4, Pc17, Pc26, Pc27, and Pc56–Pc59) were identified in South Gippsland while a single haplotype (Pc27) was found in all island koalas tested. Compared to other Victorian koala populations, greater genetic diversity found in South Gippsland koalas, may provide this population with a greater chance of survival in the face of future environmental pressures. The South Gippsland koala population is, therefore, of high conservation significance, warranting the implementation of strategies to conserve this population and its diversity into the future.     

The population genetic consequences of habitat fragmentation for plants

Habitat fragmentation reduces the size and increases the spatial isolation of plant populations. Initial predictions have been that such changes will be accompanied by an erosion of genetic variation and increased interpopulation genetic divergence due to increased random genetic drift, elevated inbreeding and reduced gene flow. Results of recent empirical studies suggest that while genetic variation may decrease with reduced remnant population size, not all fragmentation events lead to genetic losses and different types of genetic variation (e.g. allozyme and quantitative variation) may respond differently. In some circumstances, fragmentation actually appears to increase gene flow among remnant populations, breaking down local genetic structure.     

Population structure in the endangered Mauna Loa silversword, Argyroxiphium kauense (Asteraceae), and its bearing on reintroduction

Reintroduction of populations of endangered species is a challenging task, involving a number of environmental, demographic and genetic factors. Genetic parameters of interest include historical patterns of genetic structure and gene flow. Care must be taken during reintroduction to balance the contrasting risks of inbreeding and outbreeding depression. The Mauna Loa silversword, Argyroxiphium kauense, has experienced a severe decline in population size and distribution in the recent past. Currently, three populations with a total of fewer than 1000 individuals remain. We measured genetic variation within and among the remnant populations using seven microsatellite loci. We found significant genetic variation remaining within all populations, probably related to the recent nature of the population impact, the longevity of the plants, and their apparent self-incompatibility. We also found significant genetic differentiation among the populations, reinforcing previous observations of ecological and morphological differentiation. With respect to reintroduction, the results suggest that, in the absence of additional data to the contrary, inbreeding depression may not be a substantial risk as long as propagules for the founding of new populations are adequately sampled from within each source population before additional inbreeding takes place. The results further suggest that if mixing of propagules from different source populations is not required to increase within-population genetic variation in the reintroduced populations, it may best be avoided.     

Temporal genetic dynamics of reintroduced and translocated populations of the endangered golden lion tamarin (<Emphasis Type="Italic">Leontopithecus rosalia</Emphasis>)

Reintroductions—captive-born animals introduced into the species’ original distribution area—and translocations—free-living animals transferred to another location within the historical distribution area—are important conservation strategies for endangered species. Genetic analyses of 239 individuals from unmanaged, translocated and reintroduced populations of Leontopithecus rosalia were performed using 14 microsatellites. These samples were collected during two periods: (a) 1996–1997 (historic), when individuals were translocated and reintroduced into forest fragments in the lowland Atlantic Forest, and (b) 2007–09 (recent). We hypothesized that effective population size and genetic diversity would increase over time and that these management strategies would affect the resulting population genetic structure. We found trends indicating that the effective population size at the translocation site increased while that at the reintroduction sites diminished over time. The inbreeding coefficient of the translocated population diminished over time (from 0.38 to 0.03) and was much lower than that of the native (0.29) and reintroduced (0.13) recent populations. We observed a greater genetic admixture among the reintroduced sites on the historic sampling, as well as a strong genetic structure at the translocation site. In the recent sampling, the population structuring became more site-related suggesting low or inconsistent gene flow between sampling sites. This research highlights how conservation management decisions have an important influence on the genetic outcome of translocations and reintroductions. Future conservation planning should consider population genetic monitoring before and after management measures and maintain population connectivity thereafter to avoid the negative effects of a population size reduction.     

Phylogeography of the white-clawed crayfish (Austropotamobius italicus) in Spain: inferences from microsatellite markers

The white-clawed crayfish (Austropotamobius italicus), a cornerstone of Spain’s aquatic ecosystems, was once widely distributed throughout much of the country. Unfortunately, its populations have suffered very strong declines over the last 40 years due to the spread of introduced species (red swamp and signal crayfishes), diseases, habitat loss and other anthropogenic impacts. The present work examines the genetic variation in 23 Spanish and four Italian populations of white-clawed crayfish via the analysis of microsatellite loci. The data show genetic variation in the Spanish populations to be affected by drastic and successive bottlenecks. Notwithstanding, the diversity of these Spanish populations in terms of observed heterozygosity is similar to or even higher than that recorded for other European populations studied using these same markers. North-central Spanish populations are clearly differentiated from the country’s remaining populations; they should be considered distinct management units. Processes occurred in historical and recent times, such as genetic drift and translocations, contribute greatly to this genetic structure. These data provide useful information for conservation of this species, since the preservation of its population structure and genetic variability should be goals for management decisions.     

When recent and evolutionary histories meet: deciphering temporal events from contemporary patterns of mtDNA from fishers (Martes pennanti) in north‐eastern North America

The current spatial distribution of genetic lineages across a region should reflect the complex interplay of both historical and contemporary processes. Postglacial expansion and recolonization in the distant past, in combination with more recent events with anthropogenic effects such as habitat fragmentation and overexploitation, can help shape the pattern of genetic structure observed in contemporary populations. In this study, we characterize the spatial distribution of mtDNA lineages for fisher (Martes pennanti) in north‐eastern North America. The history of fishers in this region is well understood and thus provides an opportunity to interpret patterns of genetic structure in the light of known historical (e.g. recolonization from glacial refugia) and contemporary events (e.g. reintroductions, fragmentation and natural recolonization). Our results indicate that fishers likely recolonized north‐eastern North America from a single Pleistocene refugium. Three genetically distinct remnant populations persisted through the population declines of the 1800s and served as sources for multiple reintroductions and natural recolonizations that have restored the fisher throughout north‐eastern North America. However, the spatial genetic structure of genetic lineages across the region still reflects the three remnant populations.     

Isolated remnant or recent introduction? Estimating the provenance of Yellingbo Leadbeater's possums by genetic analysis and bottleneck simulation

Effective conservation management requires that genetically divergent populations potentially harbouring important local adaptations be identified and maintained as separate management units. In the case of the endangered Australian Leadbeater's possum (Gymnobelideus leadbeateri), an arboreal marsupial endemic to Victoria, uncertainty over the evolutionary origin of a potentially important extant wild population recently discovered in atypical habitat (lowland swamp) at Yellingbo is hampering such efforts. The population is rumoured to be a recent introduction. Microsatellite allele frequencies at Yellingbo differed substantially from those in sampled populations in montane ash forest (F_ST between 0.23 and 0.36), and Bayesian clustering analyses of genotypes strongly separated them (K = 2). We conducted a suite of bottlenecking tests which all indicated that Yellingbo had undergone a recent reduction in size. The extent to which the distinctiveness of Yellingbo animals might be expected solely through bottlenecking associated with a recent introduction, was tested by simulating population–history scenarios seeded with genotypes from candidate wild and captive sources. No bottleneck scenario reproduced anything approaching the genetic distinction of the Yellingbo population, with all structure analyses placing Yellingbo in a separate cluster to simulated populations (K = 2, minimum F_ST = 0.13). These results suggest that Yellingbo does not share recent ancestry with other extant populations and instead may be a remnant of an otherwise extinct gene pool. Importantly, this may include genes involved in adaptation to a lowland swamp environment, substantially adding to the conservation importance of this population, and suggesting that separate management may be prudent until evidence suggests otherwise.