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1,598 results for “genetic diversity”
Data from: The impact of anthropogenic disturbances on the genetic diversity of terrestrial species: a global meta-analysis
<p><span>Human activities are primarily responsible for habitat loss and changes in natural environments around the world. It has been suggested that populations inhabiting human-modified landscapes are subject to reduced gene flow, inbreeding depression, and loss of alleles due to genetic drift. However, empirical evidence shows contradictory effects of anthropogenic disturbances on the genetic diversity of terrestrial species. We performed a meta-analysis of 61 studies that compared the genetic diversity of plant and/or animal populations in disturbed and preserved areas (317 paired comparisons) to investigate general responses to different disturbance type. We found significant negative effects of disturbance on genetic diversity (effect size: -0.45), in which the loss of structural connectivity was the most detrimental disturbance type. The choice of the genetic parameter has an influence on the detection of the effect (direction and magnitude), and consequently the studies using number of effective alleles did not detect genetic erosion, while all other indices, especially allelic richness, revealed negative responses to disturbances. Yet, only studies performed with transferred or both transferred and specific microsatellites showed negative responses to disturbances. The general effect was more detrimental in animal than plant populations. Only plant species with biotic pollination and seed dispersal mode, self-incompatible reproductive system, and shrubs showed negative responses to disturbances. Despite all heterogeneity among studies, we found an overall negative effect of disturbance on genetic diversity of terrestrial populations, which suggests that the remaining populations inhabiting anthropogenic landscapes have a reduced evolutionary potential being more prone to local extinction.</span></p>
Assessing the genetic diversity in Argopecten nucleus (Bivalvia: Pectinidae), a functional hermaphrodite species with extremely low population density and self-fertilization: effect of null alleles
<p>Argopecten nucleus is a functional hermaphroditic pectinid species that exhibits self-fertilization, whose natural populations have usually very low densities. In the present study, the genetic diversity of a wild population from Neguanje Bay, Santa Marta (Colombia), was estimated using microsatellite markers, and the effect of the presence of null alleles on this estimation was assessed. A total of 8 microsatellite markers were developed, the first described for this species, and their amplification conditions were standardized. They were used to determine the genotype of 48 wild individuals from Naguanje Bay, and 1010 individuals derived from the offspring of 38 directed crosses. For each locus, the frequencies of the identified alleles, including null alleles, were estimated using the statistical package Micro-Checker, and the parental genotypes were confirmed using segregation analysis. Three to 8 alleles per locus with frequencies from 0.001 to 0.632 were detected. The frequencies of null alleles ranged from 0.10 to 0.45, with Ho from 0.0 to 0.79 and He from 0.53 to 0.80. All loci were in H-W disequilibrium. The null alleles frequencies values were high, with lower estimations using segregation analysis than estimated using Micro-Checker. The present results show high levels of population genetic diversity, and indicate that null alleles were not the only cause of deviation from HW equilibrium in all loci, suggesting that the wild population under study presents signs of inbreeding and Wahlun effect.</p>
Data from: Positive relationship between genetic- and species diversity on limestone outcrops in the Carpathian Mountains
We asked if the genetic diversity of Saponaria bellidifolia (a habitat specialist plant) and the species diversity of its habitat are driven by parallel landscape-level processes in an island-like system of limestone outcrops in the Carpathian Mountains. We tested the relationship of these two diversity levels at local and regional geographic scales. Local genetic and species diversity showed parallel patterns influenced by the number of plant communities. Likewise, at regional level there was strong evidence for parallel equilibrial dynamics of genotypes and species. However, a superimposed matrix effect enhanced the regional species diversity only. Genetic diversity of habitat specialist organisms and species diversity of these limestone outcrop islands on mainland are modulated by parallel landscape-level processes at different geographic scales, and mechanisms may be identified at very high spatial resolutions.
Data from: Low genetic diversity and strong population structure shaped by anthropogenic habitat fragmentation in a critically endangered primate, Trachypithecus leucocephalus
Habitat fragmentation may strongly impact population genetic structure and reduce the genetic diversity and viability of small and isolated populations. The white-headed langur (Trachypithecus leucocephalus) is a critically endangered primate species living in a highly fragmented and human-modified habitat in southern China. We examined the population genetic structure and genetic diversity of the species and investigated the environmental and anthropogenic factors that may have shaped its population structure. We used 214 unique multi-locus genotypes from 41 social groups across the main distribution area of T. leucocephalus, and found strong genetic structure and significant genetic differentiation among local populations. Our landscape genetic analyses using a causal modelling framework suggest that a large habitat gap and geographical distance represent the primary landscape elements shaping genetic structure, yet high levels of genetic differentiation also exist between patches separated by a small habitat gap or road. This is the first comprehensive study that has evaluated the population genetic structure and diversity of T. leucocephalus using nuclear markers. Our results indicate strong negative impacts of anthropogenic land modifications and habitat fragmentation on primate genetic connectivity between forest patches. Our analyses suggest that two management units of the species could be defined, and indicate that habitat continuity should be enforced and restored to reduce genetic isolation and enhance population viability.
Data from: Genetic diversity of the critically endangered lake minnow Eupallasella percnurus in Poland and its implications for conservation
The lake minnow (Eupallasella percnurus) is critically endangered. In this paper we characterize the genetic properties of this fish over its range of occurrence in Poland and propose the use of this knowledge in its active protection. Twelve populations of lake minnow from across its range in Poland were investigated. 13 microsatellite loci were investigated to evaluate genetic variation and distance among populations. The magnitude of the genetic bottleneck or founder effects was investigated. In the studied populations, the allelic diversity and heterozygosity showed that genetic variation in this species is low. At most loci, only 2–3 alleles per population were detected. The average number of alleles detected across all loci was 35, and ranged from 24 to 53. The average observed heterozygosity (Ho) across all investigated loci was 0.38 (range 0.21–0.59); the average expected heterozygosity (He) was 0.36 (range 0.18–0.55). The populations remained in Hardy-Weinberg equilibrium. The average Garza-Williamson M index value for all populations was low (0.47), suggesting a reduction in genetic variation due to a founder effect or a genetic bottleneck. Genetic distance among populations was high or very high (FST range: 0.20–0.64; δμ2 range: 1.32–16.98); this was likely a consequence of low gene flow among isolated populations, a founder effect or other genetic bottleneck, and strong genetic drift. The large genetic differences among the investigated lake minnow populations are likely to also exist among other populations of this species, and knowledge of these differences should inform active protection programs based on translocation of wild or cultivated fish of this species. The method presented here can potentially be applied to any population of lake minnows or closely related species.
Data from: Rapid buildup of genetic diversity in founder populations of the gynodioecious plant species Origanum vulgare after semi-natural grassland restoration
In most landscapes the success of habitat restoration is largely dependent on spontaneous colonization of plant species. This colonization process, and the outcome of restoration practices, can only be considered successful if the genetic makeup of founding populations is not eroded through founder effects and subsequent genetic drift. Here we used 10 microsatellite markers to investigate the genetic effects of recent colonization of the long-lived gynodioecious species Origanum vulgare in restored semi-natural grassland patches. We compared the genetic diversity and differentiation of fourteen recent populations with that of thirteen old, putative source populations, and we evaluated the effects of spatial configuration of the populations on colonization patterns. We did not observe decreased genetic diversity in recent populations, or inflated genetic differentiation among them. Nevertheless, a significantly higher inbreeding coefficient was observed in recent populations, although this was not associated with negative fitness effects. Overall population genetic differentiation was low (FST = 0.040). Individuals of restored populations were assigned to on average 6.1 different source populations (likely following the 'migrant pool' model). Gene flow was, however, affected by the spatial configuration of the grasslands, with gene flow into the recent populations mainly originating from nearby source populations. This study demonstrates how spontaneous colonization after habitat restoration can lead to viable populations in a relatively short time, overcoming pronounced founder effects, when several source populations are nearby. Restored populations can therefore rapidly act as stepping stones and sources of genetic diversity, likely increasing overall metapopulation viability of the study species.
Data from: Maintenance of genetic diversity in an introduced island population of Guanacos after seven decades and two severe demographic bottlenecks: implications for camelid conservation
Fifteen Guanacos were introduced to Staats Island in Falklands/Malvinas archipelago from Patagonia in the 1930s. After introduction, the Guanaco population increased to almost 400 animals that retained a footprint of the founding effect and bottleneck reflected in the genetic status of this isolated population. The goals of this study were to (i) make a genetic assessment of this island population through comparisons with mainland populations and simulation, and (ii) assess the likely source population of the introduced Guanacos. Genetic variation estimated from 513 bp of mitochondrial DNA sequence and 15 microsatellite loci were compared among 154 Guanacos collected from eight localities, including the adjacent mainland and the islands of Tierra del Fuego and Staats Island. Of the 23 haplotypes observed among our samples, the Staats Island population only contained three haplotypes, all of which were shared with the Monte Leon population in southern Patagonia. Mitochondrial DNA and microsatellite variation on Staats Island were comparable to most mainland populations and greater than those observed on Tierra del Fuego. Patterns of genetic structure suggest that the Staats Island Guanaco population was founded with animals from southern Patagonia (as opposed to northern Patagonia or Tierra del Fuego), but that effective reductions in population size lasted only a few generations and that surviving animals were a random sample of the pre-bottleneck genetic variation.
Data from: Postglacial recolonisation in a cold climate specialist in Western Europe: patterns of genetic diversity in the adder (Vipera berus) support the central-marginal hypothesis
Understanding the impact of postglacial recolonization on genetic diversity is essential in explaining current patterns of genetic variation. The central–marginal hypothesis (CMH) predicts a reduction in genetic diversity from the core of the distribution to peripheral populations, as well as reduced connectivity between peripheral populations. While the CMH has received considerable empirical support, its broad applicability is still debated and alternative hypotheses predict different spatial patterns of genetic diversity. Using microsatellite markers, we analysed the genetic diversity of the adder (Vipera berus) in western Europe to reconstruct postglacial recolonization. Approximate Bayesian Computation (ABC) analyses suggested a postglacial recolonization from two routes: a western route from the Atlantic Coast up to Belgium and a central route from the Massif Central to the Alps. This cold-adapted species likely used two isolated glacial refugia in southern France, in permafrost-free areas during the last glacial maximum. Adder populations further from putative glacial refugia had lower genetic diversity and reduced connectivity; therefore, our results support the predictions of the CMH. Our study also illustrates the utility of highly variable nuclear markers, such as microsatellites, and ABC to test competing recolonization hypotheses.
Data from: An invasive non-native mammal population conserves genetic diversity lost from its native range
Invasive, non-native species are one of the major causes of global biodiversity loss. Although they are, by definition, successful in their non-native range, their populations generally show major reductions in their genetic diversity during the demographic bottleneck they experience during colonization. By investigating the mitochondrial genetic diversity of an invasive non-native species, the stoat Mustela erminea, in New Zealand and comparing it to diversity in the species' native range in Great Britain, we reveal the opposite effect. We demonstrate that the New Zealand stoat population contains four mitochondrial haplotypes that have not been found in the native range. Stoats in Britain rely heavily on introduced rabbits Oryctolagus cuniculus as their primary prey and were introduced to New Zealand in a misguided attempt at biological control of rabbits, which had also been introduced there. While invasive stoats have since decimated the New Zealand avifauna, native stoat populations were themselves decimated by the introduction to Britain of Myxoma virus as a control measure for rabbits. We highlight the irony that while introduced species (rabbits) and subsequent biocontrol (myxomatosis) have caused population crashes of native stoats, invasive stoats in New Zealand, which were also introduced for biological control, now contain more genetic haplotypes than their most likely native source.
Data from: Sun skink landscape genomics: assessing how microevolutionary processes shape genetic and phenotypic diversity across a heterogeneous and fragmented landscape
Incorporating genomic data sets into landscape genetic analyses allows for powerful insights into population genetics, explicitly geographical correlates of selection, and morphological diversification of organisms across the geographical template. Here, we utilize an integrative approach to examine gene flow and detect selection, and we relate these processes to genetic and phenotypic population differentiation across South-East Asia in the common sun skink, Eutropis multifasciata. We quantify the relative effects of geographic and ecological isolation in this system and find elevated genetic differentiation between populations from island archipelagos compared to those on the adjacent South-East Asian continent, which is consistent with expectations concerning landscape fragmentation in island archipelagos. We also identify a pattern of isolation by distance, but find no substantial effect of ecological/environmental variables on genetic differentiation. To assess whether morphological conservatism in skinks may result from stabilizing selection on morphological traits, we perform FST–PST comparisons, but observe that results are highly dependent on the method of comparison. Taken together, this work provides novel insights into the manner by which micro-evolutionary processes may impact macro-evolutionary scale biodiversity patterns across diverse landscapes, and provide genomewide confirmation of classic predictions from biogeographical and landscape ecological theory.
Seedling traits from root to shoot exhibit genetic diversity and distinct responses to environmental heterogeneity within a tree population
<p>Phenotypic diversity within plant species is crucial to shaping evolutionary responses of populations and interactions among species, yet intraspecific genetic variability notably in roots has attracted little attention. Further, evidence for the root−shoot trait synchronisation remains inconclusive, narrowing our understanding of the role that belowground traits play in local adaptation. We applied broad 'top-to-toe' phenotyping to a model system whose native environmental conditions were simulated in experimental settings. Fifteen maternal families of Norway spruce <i>Picea abies </i>from southern Finland grew in six combinations of two simulated growing seasons and three soil treatments. We scored variation in 25 functional traits, including size, architecture and morphology of intact root systems, and shoot growth and phenology. Careful phenotyping of roots uncovered five trait dimensions, with root size, architecture and morphology forming the three largest axes of variation. Dimensions varied in their treatment responses. We observed among-family differences in all trait dimensions, marking substantial within-population genetic diversity. For example, average total root length varied almost twofold among families, but family × soil interactions indicated treatment-specific estimates of genetic variance. Mirroring root traits, phenotypic plasticity and genetic variation characterised shoot growth and phenology. In all, the complete phenotypic dataset yielded six trait dimensions, with assorted measures of root system and shoot size composing the main axis of variation. Although plastic and genetically variable, root architecture and morphology were not associated with shoot growth in any treatment. Also phenology and root-to-shoot ratio were detached from the primary axis of trait variability. Our results demonstrate that complex within-species patterns of trait covariation can be observed even locally and that phenotypic variation in independent trait dimensions reflecting divergent growth strategies is under genetic control. More accurate predictions of population and species responses to changes in the environment can be achieved when such intraspecific diversity is taken into account.</p>
Data from: Reduced genetic diversity and increased reproductive isolation follow population-level loss of larval dispersal in a marine gastropod
Population-level consequences of dispersal ability remain poorly understood, especially for marine animals in which dispersal is typically considered a species-level trait governed by oceanographic transport of microscopic larvae. Transitions from dispersive (planktotrophic) to non-dispersive, aplanktonic larvae are predicted to reduce connectivity, genetic diversity within populations, and the spatial scale at which reproductive isolation evolves. However, larval dimorphism within a species is rare, precluding population-level tests. We show the sea slug Costasiella ocellifera expresses both larval morphs in Florida and the Caribbean, regions with divergent mitochondrial lineages. Planktotrophy predominated at 11 sites, 10 of which formed a highly connected and genetically diverse Caribbean metapopulation. Four populations expressed mainly aplanktonic development and had markedly reduced connectivity, and lower genetic diversity at one mitochondrial and six nuclear loci. Aplanktonic dams showed partial post-zygotic isolation in most inter-population crosses, regardless of genetic or geographic distance to the sire's source, suggesting outbreeding depression affects fragmented populations. Dams from genetically isolated and neighboring populations also exhibited pre-mating isolation, consistent with reinforcement contingent on historical interaction. By increasing self-recruitment and genetic drift, the loss of dispersal may thus initiate a feedback loop resulting in the evolution of reproductive isolation over small spatial scales in the sea.
Data from: Meta-analysis reveals lower genetic diversity in overfished populations
While population declines can drive the loss of genetic diversity under some circumstances, it has been unclear whether this loss is a general consequence of overharvest in highly abundant marine fishes. Here, we use a phylogenetic approach across 160 species and 11,658 loci to show that allelic richness was on average 11% lower (p < 0.0001) in overharvested populations, even after accounting for the effects of body size, latitude, and other factors. Heterozygosity was 2% lower (p = 0.030). Simulations confirmed that these patterns are consistent with a recent bottleneck in abundant species and also showed that our analysis likely underestimates the loss of rare alleles by a factor of two or three. This evidence suggests that overharvest drives the decay of genetic diversity across a wide range of marine fishes. Such reductions of genetic diversity in some of the world's most abundant species may lead to a long-term impact of fishing on their evolutionary potential, particularly if abundance remains low and diversity continues to decay.
Data from: Development of genetic diversity, differentiation and structure over 500 years in four ponderosa pine populations
Population history plays an important role in shaping contemporary levels of genetic variation and geographic structure. This is especially true in small, isolated range-margin populations, where effects of inbreeding, genetic drift and gene flow may be more pronounced than in large continuous populations. Effects of landscape fragmentation and isolation distance may have implications for persistence of range-margin populations if they are demographic sinks. We studied four small, disjunct populations of ponderosa pine over a 500-year period. We coupled demographic data obtained through dendroecological methods with microsatellite data to discern how and when contemporary levels of allelic diversity, among and within-population levels of differentiation, and geographic structure, arose. Alleles accumulated rapidly following initial colonization, demonstrating proportionally high levels of gene flow into the populations. At population sizes of approximately 100 individuals, allele accumulation saturated. Levels of genetic differentiation among populations (FST and Jost's Dest) and diversity within populations (FIS) remained stable through time. There was no evidence of geographic genetic structure at any time in the populations' history. Proportionally, high gene flow in the early stages of population growth resulted in rapid accumulation of alleles and quickly created relatively homogenous genetic patterns among populations. Our study demonstrates that contemporary levels of genetic diversity were formed quickly and early in population development. How contemporary genetic diversity accumulates over time is a key facet of understanding population growth and development. This is especially relevant given the extent and speed at which species ranges are predicted to shift in the coming century.
Data from: Genetic diversity, demographical history and conservation aspects of the endangered yew tree Taxus contorta (syn. Taxus fuana) in Pakistan
Western Himalayan yew (Taxus contorta Griffith, synonym T. fuana Nan Li & R.R. Mill), one of the highly prized tree species for its anticancer properties is experiencing severe reduction in populations across its range in Pakistan. We examined a chloroplast DNA region (trnL-F) and ten nuclear microsatellite loci variations among seven populations to investigate the levels of genetic diversity and demographical history of T. contorta in Pakistan. Low haplotype diversity (HT = 0.182), moderate level of microsatellite diversity (HE = 0.526 ± 0.034), significant population differentiation (FST = 0.106) and high level of inbreeding (FIS = 0.222-0.418) was found in T. contorta compared with its congeners. Results of mismatch distribution analysis, neutrality tests and data on glacial chronologies of western Himalaya indicated that demographic expansion of T. contorta in Pakistan predates extensive glaciations that occurred during late Pleistocene (140.06 thousand years ago (kya), and the spatial expansion most likely happened very recently in the Holocene (6.71 kya). An unprecedented level of habitat disturbances since past few decades coupled with the severe historic climate may have played an important role on an extant population structure of T. contorta. We have discussed a range of sustainable management measures for the ecological restoration of remnant populations as well as to exploit high economic benefits that can be obtained from this species.
Data from: Male harassment, female movements, and genetic diversity in a fragmented metapopulation
Interactions with males often alter the short‐term behaviors of reproductive females. Yet, the influence of different internal and external factors, such as sexual conflict, on animal movement and patch dynamics is not well understood. We studied associations between courtship, movements of reproductive females, and genetic diversity in a small, fragmented network of Euphydras editha taylori (Taylor's checkerspot butterfly). In the absence of courtship, female movements (step lengths) were restricted (< 2 m) and tortuous, and females never departed reproductive habitat. However, when courted by males, step lengths increased markedly and movements were straighter (less tortuous). Female habitat departures were associated with interactions between patch identity and courtship. All tracked females remained in reproductive habitat in the smallest patch, whereas 32% of females departed the larger patch (over forest) while eluding courting males. Genotyping (simple sequence repeats ‐ SSRs) suggested low levels of genetic differentiation (Fst ~ 0.02; Analysis of molecular variance p = 0.02) with inter‐patch distances of ≤ 0.3 km. Tests for a recent genetic bottleneck were negative, but heterozygous deficient deviations from Hardy‐Weinberg Equilibrium expectations may indicate a developing bottleneck. Patch‐specific female movement behaviors and the distribution of SSR alleles across the network suggest the possibility of a predominantly unidirectional transfer of reproducing females from the largest to smaller patches, with the smaller patches mostly closed to emigration. Our study suggests short‐lived intraspecific interactions may influence dispersal in unanticipated ways and that understanding these interactions will provide a more holistic view of habitat fragmentation and network functioning.
Data from: Do pathogens reduce genetic diversity of their hosts? Variable effects of sylvatic plague in black-tailed prairie dogs
Introduced diseases can cause dramatic declines in—and even the loss of—natural populations. Extirpations may be followed by low recolonization rates, leading to inbreeding and a loss of genetic variation, with consequences on population viability. Conversely, extirpations may create vacant habitat patches that individuals from multiple source populations can colonize, potentially leading to an influx of variation. We tested these alternative hypotheses by sampling 15 colonies in a prairie dog metapopulation during 7 years that encompassed an outbreak of sylvatic plague, providing the opportunity to monitor genetic diversity before, during and after the outbreak. Analysis of nine microsatellite loci revealed that within the metapopulation, there was no change in diversity. However, within extirpated colonies, patterns varied: In half of the colonies, allelic richness after recovery was less than the preplague conditions, and in the other half, richness was greater than the preplague conditions. Finally, analysis of variation within individuals revealed that prairie dogs present in recolonized colonies had higher heterozygosity than those present before plague. We confirmed plague survivorship in six founders; these individuals had significantly higher heterozygosity than expected by chance. Collectively, our results suggest that high immigration rates can maintain genetic variation at a regional scale despite simultaneous extirpations in spatially proximate populations. Thus, virulent diseases may increase genetic diversity of host populations by creating vacant habitats that allow an influx of genetic diversity. Furthermore, even highly virulent diseases may not eliminate individuals randomly; rather, they may selectively remove the most inbred individuals.
Data from: Genetic diversity and distribution patterns of diploid and polyploid hybrid water frog populations (Pelophylax esculentus complex) across Europe
Polyploidization is a rare yet sometimes successful way for animals to rapidly create geno- and phenotypes that may colonize new habitats and quickly adapt to environmental changes. In this study, we use water frogs of the Pelophylax esculentus complex, comprising two species (Pelophylax lessonae, genotype LL; Pelophylax ridibundus, RR) and various diploid (LR) and triploid (LLR, LRR) hybrid forms, summarized as P. esculentus, as a model for studying recent hybridization and polyploidization in the context of speciation. Specifically, we compared the geographic distribution and genetic diversity of diploid and triploid hybrids across Europe to understand their origin, maintenance and potential role in hybrid speciation. We found that different hybrid and parental genotypes are not evenly distributed across Europe. Rather, their genetic diversity is structured by latitude and longitude and the presence/absence of parental species but not of triploids. Highest genetic diversity was observed in central and eastern Europe, the lowest in the northwestern parts of Europe. This gradient can be explained by the decrease in genetic diversity during postglacial expansion from southeastern glacial refuge areas. Genealogical relationships calculated on the basis of microsatellite data clearly indicate that hybrids are of multiple origin and include a huge variety of parental genomes. Water frogs in mixed-ploidy populations without any parental species (i.e. all-hybrid populations) can be viewed as evolutionary units that may be on their way towards hybrid speciation. Maintenance of such all-hybrid populations requires a continuous exchange of genomes between diploids and triploids, but scenarios for alternative evolutionary trajectories are discussed.
Data from: Contemporary and historic factors influence differently genetic differentiation and diversity in a tropical palm
Population genetics theory predicts loss in genetic variability because of drift and inbreeding in isolated plant populations; however, it has been argued that long-distance pollination and seed dispersal may be able to maintain gene flow, even in highly fragmented landscapes. We tested how historical effective population size, historical migration and contemporary landscape structure, such as forest cover, patch isolation and matrix resistance, affect genetic variability and differentiation of seedlings in a tropical palm (Euterpe edulis) in a human-modified rainforest. We sampled 16 sites within five landscapes in the Brazilian Atlantic forest and assessed genetic variability and differentiation using eight microsatellite loci. Using a model selection approach, none of the covariates explained the variation observed in inbreeding coefficients among populations. The variation in genetic diversity among sites was best explained by historical effective population size. Allelic richness was best explained by historical effective population size and matrix resistance, whereas genetic differentiation was explained by matrix resistance. Coalescence analysis revealed high historical migration between sites within landscapes and constant historical population sizes, showing that the genetic differentiation is most likely due to recent changes caused by habitat loss and fragmentation. Overall, recent landscape changes have a greater influence on among-population genetic variation than historical gene flow process. As immediate restoration actions in landscapes with low forest amount, the development of more permeable matrices to allow the movement of pollinators and seed dispersers may be an effective strategy to maintain microevolutionary processes.
Data from: Comparing genetic diversity and demographic history in co-distributed wild South American camelids
Vicuñas and guanacos are two species of wild South American camelids that are key ruminants in the ecosystems where they occur. Although closely related, these species feature differing ecologies and life history characters, which are expected to influence both their genetic diversity and population differentiation at different spatial scales. Here, using mitochondrial and microsatellite genetic markers, we show that vicuña display lower genetic diversity within populations than guanaco but exhibit more structure across their Peruvian range, which may reflect a combination of natural genetic differentiation linked to geographic isolation and recent anthropogenic population declines. Coalescent based demographic analyses indicate that both species have passed through a strong bottleneck, reducing their effective population sizes from over 20,000 to less than 1,000 individuals. For vicuña this bottleneck is inferred to have taken place ~3,300 years ago, but to have occurred more recently for guanaco at ~2,000 years ago. These inferred dates are considerably later than the onset of domestication (when the alpaca was domesticated from the vicuña while the llama was domesticated from the guanaco), coinciding instead with a major human population expansion following the mid-Holocene cold period. As importantly, they imply earlier declines than the well-documented Spanish conquest, where major mass mortality events were recorded for Andean human and camelid populations. We argue that underlying species' differences and recent demographic perturbations have influenced genetic diversity in modern vicuña and guanaco populations, and these processes should be carefully evaluated in the development and implementation of management strategies for these important genetic resources.
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Annotated Behaviour and Observability Dataset (ABODe)
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