Extremely Low Levels of Allozyme Variation in Southern Korean Populations of the Two Rare and Endangered Lithophytic or Epiphytic <Emphasis Type="Italic">Bulbophyllum Drymoglossum</Emphasis> and <Emphasis Type="Italic">Sarcanthus Scolopendrifolius</Emphasis> (Orchidaceae): Implications for Conservation

Allozyme variation was investigated in two local populations of Bulbophyllum drymoglossum and three populations Sarcanthus scolopendrifolius, two rare and endangered lithophytes and epiphytes from South Korea. Genetic diversity was extremely low within populations (mean H _e = 0.011 for B. drymoglossum; 0.002 for S. scolopendrifolius). Among the putative screened 21 loci, we found only one polymorphic locus for each species. Only one polymorphic locus, detected just one population of each species, revealed significantly high degree of population differentiation between and among populations (F _ST = 0.253 for B. drymoglossum and F _ST = 0.899 for S. scolopendrifolius). These results suggest that genetic drift (consequence of a very small effective population size), coupled with a limited gene flow would play a major role in shaping population genetics of these species in South Korea. The current status of both species (small population sizes, spatially isolated populations, and highly localized habitats) in addition to the extremely low levels of genetic diversity and reckless collection of endangered orchids by plant sellers, significantly threaten the long-term survival of these species in Korea. Conservation of the two species requires both in situ strategies, by introducing of genets to increase effective population sizes by minimizing adverse effects (e.g., outbreeding depression and genetic swamping by non-native genotypes), and ex situ strategies, such as collection of genets from clonal ramets.     

Genetic diversity in fragmented populations of the critically endangered spider orchid Caladenia huegelii: implications for conservation

The Orchidaceae is characterised by a diverse range of life histories, reproductive strategies and geographic distribution, reflected in a variety of patterns in the population genetic structure of different species. In this study, the genetic diversity and structure was assessed within and among remnant populations of the critically endangered sexually deceptive orchid, Caladenia huegelii. This species has experienced severe recent habitat loss in a landscape marked by ancient patterns of population fragmentation within the Southwest Australian Floristic Region, a global biodiversity hotspot. Using seven polymorphic microsatellite loci, high levels of within-population diversity (mean alleles/locus = 6.73; mean H _E = 0.690), weak genetic structuring among 13 remnant populations (F _ST = 0.047) and a consistent deficit of heterozygotes from Hardy–Weinberg expectation were found across all populations (mean F _IS = 0.22). Positive inbreeding coefficients are most likely due to Wahlund effects and/or inbreeding effects from highly correlated paternity and typically low fruit set. Indirect estimates of gene flow (Nm = 5.09 using F _ST; Nm = 3.12 using the private alleles method) among populations reflects a historical capacity for gene flow through long distance pollen dispersal by sexually deceived wasp pollinators and/or long range dispersal of dust-like orchid seed. However, current levels of gene flow may be impacted by habitat destruction, fragmentation and reduced population size. A genetically divergent population was identified, which should be a high priority for conservation managers. Very weak genetic differentiation indicates that the movement and mixing of seeds from different populations for reintroduction programs should result in minimal negative genetic effects.     

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 (F_ST and Jost's D_est) and diversity within populations (F_IS) 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.     

GENETIC DIFFERENTIATION AMONG CHEWING LOUSE POPULATIONS (MALLOPHAGA: TRICHODECTIDAE) IN A POCKET GOPHER CONTACT ZONE (RODENTIA: GEOMYIDAE)

Genetic variation among populations of chewing lice (Geomydoecus actuosi) was examined in relation to chromosomal and electrophoretic variation among populations of their hosts (Thomomys bottae) at a contact zone. Louse demes were characterized by low levels of genetic heterozygosity (H? = 0.039) that may result from founder effects during primary infestation of hosts, compounded by seasonal reductions in louse population size. Louse populations sampled from different hosts showed high levels of genetic structuring both within and among host localities. Microgeographic differentiation of louse populations is high (mean F_ST = 0.092) suggesting that properties of this host–parasite system promote differentiation of louse populations living on different individual hosts. Among-population differentiation in lice (F_ST = 0.240) was similar to that measured among host populations (F_ST = 0.236), suggesting a close association between gene flow in pocket gophers and gene flow in their lice.     

Adaptive divergence despite strong genetic drift: genomic analysis of the evolutionary mechanisms causing genetic differentiation in the island fox (Urocyon littoralis)

The evolutionary mechanisms generating the tremendous biodiversity of islands have long fascinated evolutionary biologists. Genetic drift and divergent selection are predicted to be strong on islands and both could drive population divergence and speciation. Alternatively, strong genetic drift may preclude adaptation. We conducted a genomic analysis to test the roles of genetic drift and divergent selection in causing genetic differentiation among populations of the island fox (Urocyon littoralis). This species consists of six subspecies, each of which occupies a different California Channel Island. Analysis of 5293 SNP loci generated using Restriction‐site Associated DNA (RAD) sequencing found support for genetic drift as the dominant evolutionary mechanism driving population divergence among island fox populations. In particular, populations had exceptionally low genetic variation, small N_e (range = 2.1–89.7; median = 19.4), and significant genetic signatures of bottlenecks. Moreover, islands with the lowest genetic variation (and, by inference, the strongest historical genetic drift) were most genetically differentiated from mainland grey foxes, and vice versa, indicating genetic drift drives genome‐wide divergence. Nonetheless, outlier tests identified 3.6–6.6% of loci as high F_ST outliers, suggesting that despite strong genetic drift, divergent selection contributes to population divergence. Patterns of similarity among populations based on high F_ST outliers mirrored patterns based on morphology, providing additional evidence that outliers reflect adaptive divergence. Extremely low genetic variation and small N_e in some island fox populations, particularly on San Nicolas Island, suggest that they may be vulnerable to fixation of deleterious alleles, decreased fitness and reduced adaptive potential.     

Relative performance of Bayesian clustering software for inferring population substructure and individual assignment at low levels of population differentiation

Traditional methods for characterizing genetic differentiation among populations rely on a priori grouping of individuals. Bayesian clustering methods avoid this limitation by using linkage and Hardy–Weinberg disequilibrium to decompose a sample of individuals into genetically distinct groups. There are several software programs available for Bayesian clustering analyses, all of which describe a decrease in the ability to detect distinct clusters as levels of genetic differentiation among populations decrease. However, no study has yet compared the performance of such methods at low levels of population differentiation, which may be common in species where populations have experienced recent separation or high levels of gene flow. We used simulated data to evaluate the performance of three Bayesian clustering software programs, PARTITION, STRUCTURE, and BAPS, at levels of population differentiation below F _ST=0.1. PARTITION was unable to correctly identify the number of subpopulations until levels of F _ST reached around 0.09. Both STRUCTURE and BAPS performed very well at low levels of population differentiation, and were able to correctly identify the number of subpopulations at F _ST around 0.03. The average proportion of an individual’s genome assigned to its true population of origin increased with increasing F _ST for both programs, reaching over 92% at an F _ST of 0.05. The average number of misassignments (assignments to the incorrect subpopulation) continued to decrease as F _ST increased, and when F _ST was 0.05, fewer than 3% of individuals were misassigned using either program. Both STRUCTURE and BAPS worked extremely well for inferring the number of clusters when clusters were not well-differentiated (F _ST=0.02–0.03), but our results suggest that F _ST must be at least 0.05 to reach an assignment accuracy of greater than 97%.     

Gene flow in malaria vector Anopheles stephensi (Diptera: Culicidae) across the Aravalli Hills in North-west India

The population structure of An. stephensi in North-west India was studied to assess the impact of the Aravalli Hills, as a barrier to gene flow using microsatellite markers. Large and significant genetic differentiation was found along the sides of, as well as across, the Aravalli Hills as the mean F_ST and R_ST on west vs. east of the Aravalli Hills were 0.213, 0.112 and 0.179, 0.056, respectively. Similarly, across the hills, mean values of F_ST and R_ST were 0.100 and 0.094, respectively. Genetic diversity on both sides did not vary significantly. The F_ST values were more sensitive than R_ST values, indicating that genetic drift might have caused genetic differentiation between populations. A positive correlation (r = 0.0149 and 0.157, respective to F_ST and R_ST) was found between genetic differentiations and geographic distances irrespective of the hills. Low level of gene flow was found along both sides (Nm = 0.92 and 0.14; west vs. east of Aravalli Hills, respectively) as compared to across the Aravalli Hills (Nm = 2.25). It was found that the Aravalli Hills are not working as an effective barrier to gene flow for An. Stephensi, maybe because of the low average height and discontinuous hills, however, the distance is playing a major role for differentiation between populations due to active mode of dispersal of An. stephensi mosquitoes which have a short flight range. All this information should help draw the strategies for genetic control of mosquitoes using transgenic mosquitoes.     

Molecular biogeography of the arctic-alpine disjunct burnet moth species Zygaena exulans (Zygaenidae, Lepidoptera) in the Pyrenees and Alps

Aim The phylogeography of ‘southern’ species is relatively well studied in Europe. However, there are few data about ‘northern’ species, and so we studied the population genetic structure of the arctic‐alpine distributed burnet moth Zygaena exulans as an exemplar. Location and methods The allozymes of 209 individuals from seven populations (two from the Pyrenees, five from the Alps) were studied by electrophoresis. Results All 15 analysed loci were polymorphic. The mean genetic diversities were moderately high (A: 1.99; H_e: 11.5; P: 65%). Mean genetic diversities were significantly higher in the Alps than in the Pyrenees in all cases. F_ST was 5.4% and F_IS was 10%. Genetic distances were generally low with a mean of 0.022 between large populations. About 62% of the variance between populations was between the Alps and the Pyrenees. The two samples from the Pyrenees had no significant differentiation, whereas significant differentiation was detected between the populations from the Alps (F_ST = 2.8%, P = 0.02). Main conclusion Zygaena exulans had a continuous distribution between the Alps and the Pyrenees during the last ice age. Most probably, the species was not present in Iberia, and the samples from the Pyrenees are derived from the southern edge of the glacial distribution area and thus became genetically impoverished. Post‐glacial isolation in Alps and Pyrenees has resulted in a weak genetic differentiation between these two disjunct high mountain systems.     

Drift happens: Molecular genetic diversity and differentiation among populations of jewelweed (Impatiens capensis Meerb.) reflect fragmentation of floodplain forests

Landscape features often shape patterns of gene flow and genetic differentiation in plant species. Populations that are small and isolated enough also become subject to genetic drift. We examined patterns of gene flow and differentiation among 12 floodplain populations of the selfing annual jewelweed (Impatiens capensis Meerb.) nested within four river systems and two major watersheds in Wisconsin, USA. Floodplain forests and marshes provide a model system for assessing the effects of habitat fragmentation within agricultural/urban landscapes and for testing whether rivers act to genetically connect dispersed populations. We generated a panel of 12,856 single nucleotide polymorphisms and assessed genetic diversity, differentiation, gene flow, and drift. Clustering methods revealed strong population genetic structure with limited admixture and highly differentiated populations (mean multilocus F_ST = 0.32, F_ST’ = 0.33). No signals of isolation by geographic distance or environment emerged, but alleles may flow along rivers given that genetic differentiation increased with river distance. Differentiation also increased in populations with fewer private alleles (R² = 0.51) and higher local inbreeding (R² = 0.22). Populations varied greatly in levels of local inbreeding (F_IS = 0.2–0.9) and F_IS increased in more isolated populations. These results suggest that genetic drift dominates other forces in structuring these Impatiens populations. In rapidly changing environments, species must migrate or genetically adapt. Habitat fragmentation limits both processes, potentially compromising the ability of species to persist in fragmented landscapes.     

Risso’s dolphins (<Emphasis Type="Italic">Grampus griseus</Emphasis>) in UK waters are differentiated from a population in the Mediterranean Sea and genetically less diverse

The Risso’s dolphin (Grampus griseus) has a worldwide distribution, but little is known about their population genetic structure. Local coastal populations are never known to be abundant, and are sometimes under anthropogenic impact. Therefore the question of regional differentiation by genetic drift and overall diversity levels is of conservation interest. Here we present preliminary data that clearly indicate genetic differentiation and lower genetic diversity of a population sampled in UK waters (primarily from the Western Isles, Scotland) compared to a Mediterranean sample. Significant differentiation was found in comparison with a sample from the Mediterranean for both microsatellite DNA markers (F _ST = 0.0296) and mtDNA sequence data (F _ST = 0.260; ϕ _ST = 0.542). Allelic diversity was lower in the UK for nearly all loci.     

The effects of selection,drift and genetic variation on life‐history trait divergence among insular populations of natterjack toad,Bufo calamita

Although loss of genetic variation is frequently assumed to be associated with loss of adaptive potential, only few studies have examined adaptation in populations with little genetic variation. On the Swedish west coast, the northern fringe populations of the natterjack toad Bufo calamita inhabit an atypical habitat consisting of offshore rock islands. There are strong among‐population differences in the amount of neutral genetic variation, making this system suitable for studies on mechanisms of trait divergence along a gradient of within‐population genetic variation. In this study, we examined the mechanisms of population divergence using Q_ST–F_ST comparisons and correlations between quantitative and neutral genetic variation. Our results suggest drift or weak stabilizing selection across the six populations included in this study, as indicated by low Q_ST–F_ST values, lack of significant population × temperature interactions and lack of significant differences among the islands in breeding pond size. The six populations included in this study differed in both neutral and quantitative genetic variation. Also, the correlations between neutral and quantitative genetic variation tended to be positive, however, the relatively small number of populations prevents any strong conclusions based on these correlations. Contrary to the majority of Q_ST–F_ST comparisons, our results suggest drift or weak stabilizing selection across the examined populations. Furthermore, the low heritability of fitness‐related traits may limit evolutionary responses in some of the populations.     

Allozyme variation of the pygmy wood mouse <Emphasis Type="Italic">Apodemus uralensis</Emphasis> (Rodenita,Muridae) in the ural region

Variation of 17 allozyme loci was examined in 530 Apodemus uralensis individuals caught in the Ural region from 2005 to 2007. In the populations examined, the mean value of the genetic differentiation index F _ST constituted 0.169. It was demonstrated that F _ST values for the samples obtained from the 1-km2 plot in different years, as well as for the samples trapped at a distance from 0.3 to 5 km during one year, could be remarkably higher than the mean value, pointing to their high, statistically significant differentiation. It seems likely that this differentiation was caused by spatial population subdivision, associated with the mice migrations, temporal change of the population structure, and the gene drift. Population of A. uralensis from radioactively contaminated zone displayed no specificities in the allozyme set and frequencies, which could basically distinguish these animals from the other Ural populations.     

Selection on life‐history traits and genetic population divergence in rotifers

A combination of founder effects and local adaptation – the Monopolization hypothesis – has been proposed to reconcile the strong population differentiation of zooplankton dwelling in ponds and lakes and their high dispersal abilities. The role genetic drift plays in genetic differentiation of zooplankton is well documented, but the impact of natural selection has received less attention. Here, we compare differentiation in neutral genetic markers (F_ST) and in quantitative traits (Q_ST) in six natural populations of the rotifer Brachionus plicatilis to assess the importance of natural selection in explaining genetic differentiation of life‐history traits. Five life‐history traits were measured in four temperature × salinity combinations in common‐garden experiments. Population differentiation for neutral genetic markers – 11 microsatellite loci – was very high (F_ST = 0.482). Differentiation in life‐history traits was higher in traits related to sexual reproduction than in those related to asexual reproduction. Q_ST values for diapausing egg production (a trait related to sexual reproduction) were higher than their corresponding F_ST in some pairs of populations. Our results indicate the importance of divergent natural selection in these populations and suggest local adaptation to the unpredictability of B. plicatilis habitats.     

Genome-Wide Scan for Signatures of Human Population Differentiation and Their Relationship with Natural Selection,Functional Pathways and Diseases

Genetic differences both between individuals and populations are studied for their evolutionary relevance and for their potential medical applications. Most of the genetic differentiation among populations are caused by random drift that should affect all loci across the genome in a similar manner. When a locus shows extraordinary high or low levels of population differentiation, this may be interpreted as evidence for natural selection. The most used measure of population differentiation was devised by Wright and is known as fixation index, or F_ST. We performed a genome-wide estimation of F_ST on about 4 millions of SNPs from HapMap project data. We demonstrated a heterogeneous distribution of F_ST values between autosomes and heterochromosomes. When we compared the F_ST values obtained in this study with another evolutionary measure obtained by comparative interspecific approach, we found that genes under positive selection appeared to show low levels of population differentiation. We applied a gene set approach, widely used for microarray data analysis, to detect functional pathways under selection. We found that one pathway related to antigen processing and presentation showed low levels of F_ST, while several pathways related to cell signalling, growth and morphogenesis showed high F_ST values. Finally, we detected a signature of selection within genes associated with human complex diseases. These results can help to identify which process occurred during human evolution and adaptation to different environments. They also support the hypothesis that common diseases could have a genetic background shaped by human evolution.     

Molecular and quantitative trait variation within and among small fragmented populations of the endangered plant species Psilopeganum sinense

Background and Aims

Natural selection and genetic drift are important evolutionary forces in determining genetic and phenotypic differentiation in plant populations. The extent to which these two distinct evolutionary forces affect locally adaptive quantitative traits has been well studied in common plant and animal species. However, we know less about how quantitative traits respond to selection pressures and drift in endangered species that have small population sizes and fragmented distributions. To address this question, this study assessed the relative strengths of selection and genetic drift in shaping population differentiation of phenotypic traits in Psilopeganum sinense, a naturally rare and recently endangered plant species.

Methods

Population differentiation at five quantitative traits (Q_ST) obtained from a common garden experiment was compared with differentiation at putatively neutral microsatellite markers (F_ST) in seven populations of P. sinense. Q_ST estimates were derived using a Bayesian hierarchical variance component method.

Key Results

Trait-specific Q_ST values were equal to or lower than F_ST. Neutral genetic diversity was not correlated with quantitative genetic variation within the populations of P. sinense.

Conclusions

Despite the prevalent empirical evidence for Q_ST > F_ST, the results instead suggest a definitive role of stabilizing selection and drift leading to phenotypic differentiation among small populations. Three traits exhibited a significantly lower Q_ST relative to F_ST, suggesting that populations of P. sinense might have experienced stabilizing selection for the same optimal phenotypes despite large geographical distances between populations and habitat fragmentation. For the other two traits, Q_ST estimates were of the same magnitude as F_ST, indicating that divergence in these traits could have been achieved by genetic drift alone. The lack of correlation between molecular marker and quantitative genetic variation suggests that sophisticated considerations are required for the inference of conservation measures of P. sinense from neutral genetic markers.     

Comparison of genetic differentiation at marker loci and quantitative traits

The comparison of the degree of differentiation in neutral marker loci and genes coding quantitative traits with standardized and equivalent measures of genetic differentiation (F_ST and Q_ST, respectively) can provide insights into two important but seldom explored questions in evolutionary genetics: (i) what is the relative importance of random genetic drift and directional natural selection as causes of population differentiation in quantitative traits, and (ii) does the degree of divergence in neutral marker loci predict the degree of divergence in genes coding quantitative traits? Examination of data from 18 independent studies of plants and animals using both standard statistical and meta‐analytical methods revealed a number of interesting points. First, the degree of differentiation in quantitative traits (Q_ST) typically exceeds that observed in neutral marker genes (F_ST), suggesting a prominent role for natural selection in accounting for patterns of quantitative trait differentiation among contemporary populations. Second, the F_ST – Q_ST difference is more pronounced for allozyme markers and morphological traits, than for other kinds of molecular markers and life‐history traits. Third, very few studies reveal situations were Q_ST < F_ST, suggesting that selection pressures, and hence optimal phenotypes, in different populations of the same species are unlikely to be often similar. Fourth, there is a strong correlation between Q_ST and F_ST indices across the different studies for allozyme (r=0.81), microsatellite (r=0.87) and combined (r=0.75) marker data, suggesting that the degree of genetic differentiation in neutral marker loci is closely predictive of the degree of differentiation in loci coding quantitative traits. However, these interpretations are subject to a number of assumptions about the data and methods used to derive the estimates of population differentiation in the two sets of traits.     

Genetic structure of Brandt’s vole (<Emphasis Type="Italic">Lasiopodomys brandtii</Emphasis>) populations in Inner Mongolia,China, based on microsatellite analysis

Brandt’s vole (Lasiopodomys brandtii) distribution is discontinuous in Inner Mongolia with some populations isolated from others. Recently, some isolated populations have suffered extinction, and the factors responsible remain elusive. Genetic drift is one of the processes affecting population genetic differentiation, and can play a substantial role in the divergence of small, isolated populations. Using seven microsatellite markers, we genotyped four geographically isolated populations of Brandt’s vole, all of which exhibit episodic fluctuations in population density. The results showed a strong genetic differentiation among the geographically distinct populations (total F _ST = 0.124) and in particular, one population (Zhengxiangbaiqi) was isolated from all others (F _ST values were greatest between Zhengxiangbaiqi and other populations). Furthermore, high levels of inbreeding (F _IS values ranged from 0.205 to 0.290) within each distinct population suggest that inbreeding has and is likely occurring in Brandt’s vole populations. These processes can decrease average individual fitness and consequently increase the risk of extinction of the species.     

Genetic diversity and population differentiation in the yellow drum Nibea albiflora along the coast of the China Sea

Nibea albiflora (yellow drum) is an important seafood fish species in East Asia. We explored the population genetic variation of N. albiflora along the coastal waters of the China Sea using microsatellite markers to facilitate a selective breeding programme that is undertaken in China. A total of 256 alleles were detected at 12 loci in four wild populations. A high level of genetic diversity was observed with the mean number of alleles and the observed and expected heterozygosity in each population ranging from 7.917 to 14.083, 0.701 to 0.764 and 0.765 to 0.841, respectively. Pairwise fixation index (F_ST) analysis indicated significant but weak genetic differentiation among populations from four localities (F_ST?=?0.030, P?<?0.01), which was also confirmed by analysis of molecular variance (AMOVA). Significant genetic differentiation was detected between Ningde and the other populations (F_ST?=?0.047–0.056, P?<?0.01). Structure analysis suggested that N. albiflora within the examined range might be composed of two stocks. The data of the present study revealed high genetic diversity and low genetic differentiation among the N. albiflora populations along the coast of the China Sea. This baseline information could be valuable for future selective breeding programmes of N. albiflora.     

Genetic structure of the clonal herb Tanakaea radicans (Saxifragaceae) at multiple spatial scales,revealed by nuclear and mitochondrial microsatellite markers

The genus Tanakaea is a plant genus that consists of one or two evergreen herbaceous species in Japan and China. As rithophytic plant species occur on shaded rocks, the populations are usually isolated and sporadically found in disjunct areas. To evaluate the genetic structure of the species at multiple spatial scales, 10 nuclear and mitochondrial microsatellite markers were developed. The novel markers showed high genetic variations (two to 15 alleles and H_e from 0.400 to 0.894). Clonal samples were identified with the probability of identity of 9.0E‐8. When evaluated with 11 populations in Japan, significant genetic differentiation between regional population groups was detected (F_ST = 0.313 between Shikoku and Honshu islands), suggesting they have long been isolated from each other. Overall, these markers will be useful for population genetic research to investigate clonal structure and genetic diversity and levels of genetic differentiation between the geographically isolated populations.     

Local selection modifies phenotypic divergence among Rana temporaria populations in the presence of gene flow

In ectotherms, variation in life history traits among populations is common and suggests local adaptation. However, geographic variation itself is not a proof for local adaptation, as genetic drift and gene flow may also shape patterns of quantitative variation. We studied local and regional variation in means and phenotypic plasticity of larval life history traits in the common frog Rana temporaria using six populations from central Sweden, breeding in either open‐canopy or partially closed‐canopy ponds. To separate local adaptation from genetic drift, we compared differentiation in quantitative genetic traits (Q_ST) obtained from a common garden experiment with differentiation in presumably neutral microsatellite markers (F_ST). We found that R. temporaria populations differ in means and plasticities of life history traits in different temperatures at local, and in F_ST at regional scale. Comparisons of differentiation in quantitative traits and in molecular markers suggested that natural selection was responsible for the divergence in growth and development rates as well as in temperature‐induced plasticity, indicating local adaptation. However, at low temperature, the role of genetic drift could not be separated from selection. Phenotypes were correlated with forest canopy closure, but not with geographical or genetic distance. These results indicate that local adaptation can evolve in the presence of ongoing gene flow among the populations, and that natural selection is strong in this system.