Genetic Changes In Populations Research Articles

Extensive hybridization following a large escape of domesticated Atlantic salmon in the Northwest Atlantic

Domestication is rife with episodes of interbreeding between cultured and wild populations, potentially challenging adaptive variation in the wild. In Atlantic salmon, Salmo salar, the number of domesticated individuals far exceeds wild individuals, and escape events occur regularly, yet evidence of the magnitude and geographic scale of interbreeding resulting from individual escape events is lacking. We screened juvenile Atlantic salmon using 95 single nucleotide polymorphisms following a single, large aquaculture escape in the Northwest Atlantic and report the landscape-scale detection of hybrid and feral salmon (27.1%, 17/18 rivers). Hybrids were reproductively viable, and observed at higher frequency in smaller wild populations. Repeated annual sampling of this cohort revealed decreases in the presence of hybrid and feral offspring over time. These results link previous observations of escaped salmon in rivers with reports of population genetic change, and demonstrate the potential negative consequences of escapes from net-pen aquaculture on wild populations.

Estimation of fitness from energetics and life-history data: An example using mussels.

Changing environments have the potential to alter the fitness of organisms through effects on components of fitness such as energy acquisition, metabolic cost, growth rate, survivorship, and reproductive output. Organisms, on the other hand, can alter aspects of their physiology and life histories through phenotypic plasticity as well as through genetic change in populations (selection). Researchers examining the effects of environmental variables frequently concentrate on individual components of fitness, although methods exist to combine these into a population level estimate of average fitness, as the per capita rate of population growth for a set of identical individuals with a particular set of traits. Recent advances in energetic modeling have provided excellent data on energy intake and costs leading to growth, reproduction, and other life‐history parameters; these in turn have consequences for survivorship at all life‐history stages, and thus for fitness. Components of fitness alone (performance measures) are useful in determining organism response to changing conditions, but are often not good predictors of fitness; they can differ in both form and magnitude, as demonstrated in our model. Here, we combine an energetics model for growth and allocation with a matrix model that calculates population growth rate for a group of individuals with a particular set of traits. We use intertidal mussels as an example, because data exist for some of the important energetic and life‐history parameters, and because there is a hypothesized energetic trade‐off between byssus production (affecting survivorship), and energy used for growth and reproduction. The model shows exactly how strong this trade‐off is in terms of overall fitness, and it illustrates conditions where fitness components are good predictors of actual fitness, and cases where they are not. In addition, the model is used to examine the effects of environmental change on this trade‐off and on both fitness and on individual fitness components.

After 100 years: hydroelectric dam-induced life-history divergence and population genetic changes in sockeye salmon (Oncorhynchus nerka)

Understanding the impact of barriers and habitat fragmentation on the ecology and genetics of species is of broad interest to many biologists. In aquatic systems, hydroelectric dams often present an impenetrable barrier to migratory fish and can have negative effects on their persistence. Hydroelectric dams constructed in the Coquitlam and Alouette Rivers in the Fraser River drainage (British Columbia, Canada) in the early 1900s were thought to have led to complete loss of anadromous sockeye salmon from both rivers. For both reservoirs, recent water release programs resulted in the unexpected downstream migration of juvenile sockeye salmon and the subsequent upstream migration of adults towards the reservoir 2 years later. Here we investigate the evolutionary impact of dams on the sockeye salmon migration behavior by investigating the genetic distinction between migratory and non-migratory individuals within the Alouette and Coquitlam reservoirs. We also compare historical and contemporary genetic connectivity among 11 Lower Fraser River sockeye sites to infer recent population connectivity changes that might have been influenced by anthropogenic activities. Our molecular genetic analyses show a genetic distinction between the sea-run and resident individuals from the Coquitlam reservoir and population splitting time estimates suggest a very recent divergence between them. These results indicate a genetic component to migration behavior. For our broader survey from 11 sites, our comparisons suggest a general decline in gene flow, with a few interesting exceptions. In summary, our results suggest (i) early stage divergence between life history forms of sockeye salmon within one reservoir, and (ii) recent changes in genetic connectivity among Lower Fraser River populations; both of these results have potential recovery implications for historically migratory populations that were affected by anthropogenic barriers such as hydroelectric dams.

Small terrestrial mammals living along streams acting as natural landscape barriers

Abstract Riparian stands along streams are important landscape elements – biocorridors, allowing the dispersal of many small terrestrial mammals. Streams are, however, also barriers limiting dispersal, which leads to isolation and population-genetic changes. Communities of small terrestrial mammals (Eulipotyphla, Rodentia) were studied in 2004 to 2006 on five watercourses of varying widths in Central European cultural landscape situated in South Bohemia (Czech Republic). In total, 547 individuals from 10 species were captured by the Capture-Mark-Recapture method (CMR). Yellow-necked mouse (Apodemus flavicollis) and bank voles (Myodes glareolus) were eu-dominant species at all locations. Species diversity and equitability rose with the degree of the barrier – proportional to the width of the stream. The terrestrial mobility of selected species was also assessed. Apodemus flavicollis indicated overall highest values of mobility, and Myodes glareolus males also scored higher values, however, the width of the stream did not correlate with mobility in these species. The animals crossed water-courses on the order of tens of meters wide in the period of 3 months. The frequency of crossing of Apodemus flavicollis decreased exponentially with the width of the stream and was dependent on population density.

IBSEM: An Individual-Based Atlantic Salmon Population Model.

Ecology and genetics can influence the fate of individuals and populations in multiple ways. However, to date, few studies consider them when modelling the evolutionary trajectory of populations faced with admixture with non-local populations. For the Atlantic salmon, a model incorporating these elements is urgently needed because many populations are challenged with gene-flow from non-local and domesticated conspecifics. We developed an Individual-Based Salmon Eco-genetic Model (IBSEM) to simulate the demographic and population genetic change of an Atlantic salmon population through its entire life-cycle. Processes such as growth, mortality, and maturation are simulated through stochastic procedures, which take into account environmental variables as well as the genotype of the individuals. IBSEM is based upon detailed empirical data from salmon biology, and parameterized to reproduce the environmental conditions and the characteristics of a wild population inhabiting a Norwegian river. Simulations demonstrated that the model consistently and reliably reproduces the characteristics of the population. Moreover, in absence of farmed escapees, the modelled populations reach an evolutionary equilibrium that is similar to our definition of a ‘wild’ genotype. We assessed the sensitivity of the model in the face of assumptions made on the fitness differences between farm and wild salmon, and evaluated the role of straying as a buffering mechanism against the intrusion of farm genes into wild populations. These results demonstrate that IBSEM is able to capture the evolutionary forces shaping the life history of wild salmon and is therefore able to model the response of populations under environmental and genetic stressors.

Temporal genetic and demographic monitoring of pond-breeding amphibians in three contrasting population systems

Quantifying the relationship between demographic patterns and genetic diversity are important in predicting temporal population genetic changes. To make predictions there must be an understanding of the relationship between census size, the effective number of breeders (Nb) and effective population size (Ne). We evaluate the temporal genetic variation between three populations of Ambystoma salamanders, and compare genetic and demographic estimates of Nb and Ne. We sampled two wetlands, RB and GB for A. opacum and sampled A. talpoideum at RB, over a 20-year period. Ambystoma opacum colonized the RB wetland in 1980 and the population has steadily expanded as A. talpoideum has declined towards local extinction; the GB population of A. opacum has remained relatively large and stable over this same time period. Genetic variation at 10 microsatellites remained stable at each population over the sampled time frame, and did not reflect changes in population size. Genetic estimates of Nb also did not reflect demographic trends, and were lower than demographic estimates of Nb. Genetic methods of determining Ne gave similar estimates to demographic methods. Our findings indicate that sample sizes and number of markers typically used in genetic studies do not provide enough precision to monitor population size changes in amphibians, which likely violate many of the assumptions of Nb and Ne estimation models. These findings should be considered when using Ne in conservation and management assessments of amphibian populations.

Coincidence of virulence shifts and population genetic changes of Pseudoperonospora cubensis in the Czech Republic

Pseudoperonospora cubensis is an oomycete pathogen causing downy mildew disease on a variety of Cucurbitaceae, and has recently re‐emerged as a destructive disease on crops in this family, mainly on cucumber and squash. Multilocus sequence analysis (MLSA) of four mitochondrial and two nuclear DNA regions was used to detect changes in the genetic structure of P. cubensis populations occurring in the Czech Republic that might be associated with recently reported shifts in virulence. The analysed sample set contains 67 P. cubensis isolates collected from 1995 to 2012 in the Czech Republic and some other European countries. Sequence analyses revealed differences and changes in the genetic backgrounds of P. cubensis isolates. While all isolates sampled before 2009 exhibited the genotype of the subspecies of Clade II and were collected from cucumber, all samples collected from other hosts belonged to Clade I (P. cubensis sensu stricto) or were sampled from 2009 onwards. In addition, 67·16% of all post‐2009 isolates from Clade II had two heterozygous positions in their nrITS sequence, which suggests sexual reproduction and/or a mutational origin. Thus, the results indicate that, apart from the rise in prevalence of Clade I, the change in the genetic structure of P. cubensis populations may be linked with a hybridization or, less likely, a mutation event that rendered strains able to infect a broader spectrum of host species.

Simple phenotypic sweeps hide complex genetic changes in populations.

Changes in allele frequencies and the fixation of beneficial mutations are central to evolution. The precise relationship between mutational and phenotypic sweeps is poorly described however, especially when multiple alleles are involved. Here, we investigate these relationships in a bacterial population over 60 days in a glucose-limited chemostat in a large population. High coverage metagenomic analysis revealed a disconnection between smooth phenotypic sweeps and the complexity of genetic changes in the population. Phenotypic adaptation was due to convergent evolution and involved soft sweeps by 7–26 highly represented alleles of several genes in different combinations. Allele combinations spread from undetectably low baselines, indicating that minor subpopulations provide the basis of most innovations. A hard sweep was also observed, involving a single combination of rpoS, mglD, malE, sdhC, and malT mutations sweeping to greater than 95% of the population. Other mutant genes persisted but at lower abundance, including hfq, consistent with its demonstrated frequency-dependent fitness under glucose limitation. Other persistent, newly identified low-frequency mutations were in the aceF, galF, ribD and asm genes, in noncoding regulatory regions, three large indels and a tandem duplication; these were less affected by fluctuations involving more dominant mutations indicating separate evolutionary paths. Our results indicate a dynamic subpopulation structure with a minimum of 42 detectable mutations maintained over 60 days. We also conclude that the massive population-level mutation supply in combination with clonal interference leads to the soft sweeps observed, but not to the exclusion of an occasional hard sweep.

Influence of hybridization on niche shifts in expanding coyote populations

AbstractAimThe degree to which niches of species change over time or space has important implications for ecology and evolutionary biology. However, conditions that give rise to niche shifts remain poorly understood. In particular, the relative influence of release from predation or competition (change in realized niche) vs. genetically based alterations (change in fundamental niche) has received little attention. We studied niche shifts in expanding coyote (Canis latrans) populations. During expansion from their historic range, coyotes experienced marked changes in competitive regimes and also genetic changes (i.e. hybridization), and these alterations occurred unevenly across the expanding front. The goal of this study was to determine the presence and degree of niche shifts in expanding coyote populations and the potential influence of hybridization on these patterns.LocationNorth America.MethodsWe developed species distribution models and compared climatic niche overlap between historic and expanding coyote populations with different levels of genetic introgression with wolves. We also developed harvest models to examine differences in how coyote and coyote hybrids responded to human disturbance and land use.ResultsNiche differentiation is most pronounced for expanding coyote populations that have experienced substantial hybridization with wolves. An examination of response curves suggests that coyotes in the north‐east may have shifted to a more wolflike niche.Main conclusionsHybridization or other processes that promote genetic changes in populations may be associated with niche shifts. These findings help explain why hybridization often leads to increased invasiveness, and further support the notion that genetic differentiation below the level of species can lead to niche divergence. Our results also highlight the caution needed when predicting distributional changes due to invasion or climate change, particularly among populations exposed to genetic change.

The characterization and antibiotic resistance profiles of clinical Escherichia coli O25b-B2-ST131 isolates in Kuwait.

BackgroundEscherichia coli O25b-B2-ST131 are considered virulent extra-intestinal pathogens causing serious clinical complications such as urinary tract infection and bacteraemia. Our main objectives in this study were to characterise the multi-drug resistant (MDR) isolates of this lineage in Kuwait, and to demonstrate whether reduced susceptibility is spread clonally.ResultsA subset of 83 (10%) non-duplicate and non-selective E. coli O25b-B2-ST131 out of 832 MDR E. coli was identified and collected. Minimum inhibitory concentrations of the isolates were determined and pulsed-field gel electrophoresis was used for typing.The majority (95.2%) of the 83 E. coli O25b-B2-ST131 harboured at least one bla gene with blaCTX-M-15 being the most prevalent. blaCTX-M-2 was present in one isolate. Also one isolate harboured blaCTX-M-56, qnrB1 and blaCMY-2 genes and carried IncF1 plasmids of about 97 kb and160 kb. qnrB and qnrS were found in 8 other blaCTX-M-15 containing isolates. The blaNDM, blaIMP, blaVIM and qnrA were not detected, however, the blaOXA-48 was present in two (2.4%).ConclusionsThe majority of isolates harbouring qnr genes demonstrated relatedness (≥85%) by PFGE. However, the diversity in PFGE profiles for the other MDR isolates reflected the changes in population genetics of E. coli O25b-B2-ST131. We identified for the first time the appearance of blaCTX-M-2 in the Middle East and blaCTX-M-56 outside the Latin American countries. The isolate harbouring blaCTX-M-56 also contained qnrB1 and blaCMY-2 genes and carried IncF1 plasmids. The appearance of a highly virulent E. coli O25b-ST131 that is resistant to penicillins, most cephalosproins, β-lactamase inhibitors as well as fluoroquinolones is a cause for concern.Electronic supplementary materialThe online version of this article (doi:10.1186/s12866-014-0214-6) contains supplementary material, which is available to authorized users.

Genetic risks of supplementing trout populations with native stocks: a simulation case study from current Pyrenean populations

The risks of supplementation must be examined to assess the genetic effects to native wild populations before full implementation or exclusion of programs that involve captive breeding and release. Real genetic data can be applied to simulations of genetic changes in populations of interest and subsequently used in risk assessment. Ancestral Mediterranean brown trout (Salmo trutta) lineages exhibit complex population structure among native populations. Genetically divergent Atlantic stocks were maintained and released in the Mediterranean rivers as recreational fish, which resulted in hybridization and introgression with local populations. Therefore, we designed a new supplementation program based on native stocks and evaluated the genetic risks associated with releasing native fish in recreational fisheries. Our simulation was delimited by the observed population genetic structure and available hatchery facilities in the study region. Supplementation with native stocks maintained estimates of gene diversity indexes (total diversity (HT), local diversity (HS), and population differentiation (GST)). However, simulations indicated that long-term supplementation significantly reduced genetic diversity among locations because of a homogenizing effect of populations along each management unit. Therefore, such reinforcements compromised the conservation of local genetic variation. Nevertheless, replacement of current foreign stocks with native stocks can be an important step towards promoting the value of preserving local diversity among anglers.

Genetic Considerations in the Restoration of Small Forest Populations: Perspectives From Fish and Wildlife Genetics

The evolutionary forces that drive recent population genetic changes include migration, mating strategy, genetic drift, and selection. However, the strength of these forces varies depending on population size. The purpose of this article is to review genetic issues associated with small forest populations and to provide perspectives from fish and wildlife genetics through case studies. Small populations are often fragmented, potentially preventing migration. In forest trees, long-distance pollen dispersal and highly mobile, generalist pollinators can help maintain connectivity. A landscape and community approach to understanding connectivity is critical (case study: mussels). Outbreeding depression can also be a concern in forest restoration. This becomes a greater risk when mixing populations that are highly diverged and when the species is polyploid. Management units should be designated that mimic natural gene flow (case study: lake sturgeon). At the other extreme, inbreeding depression can result in reduced fitness. When inbreeding depression is a concern, genetic rescue may be necessary (case study: Florida panther). Loss of diversity through genetic drift can occur with small effective population sizes (Ne) and a small number of founders (case study: salmonids). Selection is most likely to occur through adaptation to captivity or introduction of resistant/tolerant strains (case study: amphibians).

Lack of Detectable HIV-1 Molecular Evolution during Suppressive Antiretroviral Therapy

A better understanding of changes in HIV-1 population genetics with combination antiretroviral therapy (cART) is critical for designing eradication strategies. We therefore analyzed HIV-1 genetic variation and divergence in patients' plasma before cART, during suppression on cART, and after viral rebound. Single-genome sequences of plasma HIV-1 RNA were obtained from HIV-1 infected patients prior to cART (N = 14), during suppression on cART (N = 14) and/or after viral rebound following interruption of cART (N = 5). Intra-patient population diversity was measured by average pairwise difference (APD). Population structure was assessed by phylogenetic analyses and a test for panmixia. Measurements of intra-population diversity revealed no significant loss of overall genetic variation in patients treated for up to 15 years with cART. A test for panmixia, however, showed significant changes in population structure in 2/10 patients after short-term cART (<1 year) and in 7/10 patients after long-term cART (1–15 years). The changes consisted of diverse sets of viral variants prior to cART shifting to populations containing one or more genetically uniform subpopulations during cART. Despite these significant changes in population structure, rebound virus after long-term cART had little divergence from pretherapy virus, implicating long-lived cells infected before cART as the source for rebound virus. The appearance of genetically uniform virus populations and the lack of divergence after prolonged cART and cART interruption provide strong evidence that HIV-1 persists in long-lived cells infected before cART was initiated, that some of these infected cells may be capable of proliferation, and that on-going cycles of viral replication are not evident.

Fine-Scale Genetic Response to Landscape Change in a Gliding Mammal

Understanding how populations respond to habitat loss is central to conserving biodiversity. Population genetic approaches enable the identification of the symptoms of population disruption in advance of population collapse. However, the spatio-temporal scales at which population disruption occurs are still too poorly known to effectively conserve biodiversity in the face of human-induced landscape change. We employed microsatellite analysis to examine genetic structure and diversity over small spatial (mostly 1-50 km) and temporal scales (20-50 years) in the squirrel glider (Petaurus norfolcensis), a gliding mammal that is commonly subjected to a loss of habitat connectivity. We identified genetically differentiated local populations over distances as little as 3 km and within 30 years of landscape change. Genetically isolated local populations experienced the loss of genetic diversity, and significantly increased mean relatedness, which suggests increased inbreeding. Where tree cover remained, genetic differentiation was less evident. This pattern was repeated in two landscapes located 750 km apart. These results lend support to other recent studies that suggest the loss of habitat connectivity can produce fine-scale population genetic change in a range of taxa. This gives rise to the prediction that many other vertebrates will experience similar genetic changes. Our results suggest the future collapse of local populations of this gliding mammal is likely unless habitat connectivity is maintained or restored. Landscape management must occur on a fine-scale to avert the erosion of biodiversity.

Cytological and Population Genetic Changes in Northwestern Iberian Mussels After the Prestige Oil Spill

The ecological catastrophe produced by the Prestige oil spill (November 2002) caused severe damage in both North Spanish and French coastal communities. Wild mussel populations of Mytilus galloprovincialis in a zone with marginal introgression of Mytilus edulis were affected at all levels, from high DNA damage to increased polycyclic aromatic hydrocarbon content in tissues. In this article, we describe cytological and population genetic changes of wild mussel populations from the northwestern Iberian coast following the catastrophe. The micronucleus test was employed as an indicator of cytological damage, and the Barcoding mitochondrial cytochrome oxidase I (COI) and the nuclear Glu-5′ genes were analyzed for determining the species and assessing population genetic diversity. Immediate increase of micronuclei counts after the oil spill was found, with a further decrease in consecutive months although the counts did not recover pre-Prestige levels. Reduced variation at mitochondrial sequences in the most exposed areas and reduction of M. edulis traces in the regional genetic pool also suggest long-term impact that may result in evolutionary changes. These results highlight the need of adopting more strict measures in order to prevent this type of accidents and avoid long-term effects on wild populations.

Individual differences in migratory behavior shape population genetic structure and microhabitat choice in sympatric blackcaps (Sylvia atricapilla)

In migratory birds, traits such as orientation and distance are known to have a strong genetic background, and they often exhibit considerable within-population variation. How this variation relates to evolutionary responses to ongoing selection is unknown because the underlying mechanisms that translate environmental changes into population genetic changes are unclear. We show that within-population genetic structure in southern German blackcaps (Sylvia atricapilla) is related to individual differences in migratory behavior. Our 3-year study revealed a positive correlation between individual migratory origins, denoted via isotope (δ2H) values, and genetic distances. Genetic diversity and admixture differed not only across a recently established migratory polymorphism with NW- and SW-migrating birds but also across δ2H clusters within the same migratory route. Our results suggest assortment based on individual migratory origins which would facilitate evolutionary responses. We scrutinized arrival times and microhabitat choice as potential mechanisms mediating between individual variation in migratory behavior and assortment. We found significant support that microhabitat choice, rather than timing of arrival, is associated with individual variation in migratory origins. Moreover, examining genetic diversity across the migratory divide, we found migrants following the NW route to be genetically more distinct from each other compared with migrants following the traditional SW route. Our study suggests that migratory behavior shapes population genetic structure in blackcaps not only across the migratory divide but also on an individual level independent of the divide. Thus, within-population variation in migratory behavior might play an important role in translating environmental change into genetic change.

Microsatellite markers for the palaeo-temperature indicator Pentapharsodinium dalei (Dinophyceae)

Pentapharsodinium dalei is a widely distributed cold-water dinoflagellate, which is used in palaeoecology as an indicator of relatively warmer conditions in polar and sub-polar regions. This species has been proposed to be one of the first indicators of global warming at high latitudes. We developed the first microsatellite markers for P. dalei to facilitate the study of spatial and temporal population genetic changes. Single cysts were isolated from surface sediments in Koljo Fjord, Sweden. After cyst germination, single vegetative cells were isolated for establishing monoclonal cultures. Six dinucleotide polymorphic microsatellite markers were developed as multiplex polymerase chain reactions and were genotyped in 32 strains. The number of alleles per locus varied between 4 and 12, and the estimated gene diversity varied from 0.588 to 0.891. The haploid state of the vegetative cells was confirmed. The six selected microsatellites will be useful to explore population dynamics in P. dalei from contemporary planktonic and revived benthic samples to enable, for example, detailed studies into the evolutionary consequences of anthropogenic and climate-driven habitat changes.

Interannual variation in effective number of breeders and estimation of effective population size in long‐lived iteroparous lake sturgeon (Acipenser fulvescens)

Quantifying interannual variation in effective adult breeding number (N(b)) and relationships between N(b), effective population size (N(e)), adult census size (N) and population demographic characteristics are important to predict genetic changes in populations of conservation concern. Such relationships are rarely available for long-lived iteroparous species like lake sturgeon (Acipenser fulvescens). We estimated annual N(b) and generational N(e) using genotypes from 12 microsatellite loci for lake sturgeon adults (n = 796) captured during ten spawning seasons and offspring (n = 3925) collected during larval dispersal in a closed population over 8 years. Inbreeding and variance N(b) estimated using mean and variance in individual reproductive success derived from genetically identified parentage and using linkage disequilibrium (LD) were similar within and among years (interannual range of N(b) across estimators: 41-205). Variance in reproductive success and unequal sex ratios reduced N(b) relative to N on average 36.8% and 16.3%, respectively. Interannual variation in N(b)/N ratios (0.27-0.86) resulted from stable N and low standardized variance in reproductive success due to high proportions of adults breeding and the species' polygamous mating system, despite a 40-fold difference in annual larval production across years (437-16 417). Results indicated environmental conditions and features of the species' reproductive ecology interact to affect demographic parameters and N(b)/N. Estimates of N(e) based on three single-sample estimators, including LD, approximate Bayesian computation and sibship assignment, were similar to annual estimates of N(b). Findings have important implications concerning applications of genetic monitoring in conservation planning for lake sturgeon and other species with similar life histories and mating systems.

Sea Turtle Migration: What Kind of Cue they Use for Navigation?

Sea Turtle Migration: What Kind of Cue they Use for Navigation? Sea turtle is a long-lived marine reptile. The long evolution history of this animal results in great interests to understand its population traits. However, the endangered status of sea turtle prevents us from conducting extensive studies. In spite of great efforts have devoted to the researches on the biology of sea turtle, little progress was achieved for decades. Only in recent years, the advancement of technologies allows us to solve these miseries gradually. Current major topics involves in population genetic, biologging (e.g. satellite telemetries, diving behavior), nesting ecology (include nesting environment and embryogenesis), diet, pollution, plasma biochemistries, parasites, fisheries interactions and global climate changes.

Forecasting changes in population genetic structure of alpine plants in response to global warming

Species range shifts in response to climate and land use change are commonly forecasted with species distribution models based on species occurrence or abundance data. Although appealing, these models ignore the genetic structure of species, and the fact that different populations might respond in different ways because of adaptation to their environment. Here, we introduced ancestry distribution models, that is, statistical models of the spatial distribution of ancestry proportions, for forecasting intra-specific changes based on genetic admixture instead of species occurrence data. Using multi-locus genotypes and extensive geographic coverage of distribution data across the European Alps, we applied this approach to 20 alpine plant species considering a global increase in temperature from 0.25 to 4 °C. We forecasted the magnitudes of displacement of contact zones between plant populations potentially adapted to warmer environments and other populations. While a global trend of movement in a north-east direction was predicted, the magnitude of displacement was species-specific. For a temperature increase of 2 °C, contact zones were predicted to move by 92 km on average (minimum of 5 km, maximum of 212 km) and by 188 km for an increase of 4 °C (minimum of 11 km, maximum of 393 km). Intra-specific turnover-measuring the extent of change in global population genetic structure-was generally found to be moderate for 2 °C of temperature warming. For 4 °C of warming, however, the models indicated substantial intra-specific turnover for ten species. These results illustrate that, in spite of unavoidable simplifications, ancestry distribution models open new perspectives to forecast population genetic changes within species and complement more traditional distribution-based approaches.