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Genetic monitoring of populations currently attracts interest in the context of the Convention on Biological Diversity but needs long-term planning and investments. Genetic diversity has been largely neglected in biodiversity monitoring, and when addressed is treated separately, detached from other conservation issues, such as habitat alteration due to climate change. Genetic monitoring supports the conservation and management of fisheries, game, and threatened populations. It also can contribute to the assessment of predicted and realized impacts of climate change, and their management. We report the first accounting of genetic monitoring efforts among countries in Europe (their ‘genetic monitoring capacity’, GMC) to determine where GMC suggests the combination of national infrastructure, political support and resources for continued and expanded monitoring. Overlaying GMC with areas where species ranges approach current and future climate niche limits (i.e., niche marginality) helps identify whether GMC coincides with anticipated climate change effects on biodiversity. Our analysis suggests that country area extent, financial resources, and conservation policy influence GMC, high values of which inconsistently match joint species patterns of climate niche marginality. Populations at niche margins likely hold genetic diversity that is important to adaptation to changing climate, and our results illuminate the need in Europe for expanded genetic monitoring across the climate gradients occupied by species, a need arguably greatest in southeastern European countries.

Understanding how obligate freshwater organisms colonize seemingly isolated ecosystems has long fascinated ecologists. While recent investigations reveal that fish eggs can survive the digestive tract of birds and successfully hatch once deposited, evidence for avian zoochory in natura is still lacking. Here, we used a ‘multiple lines and levels of evidence’ approach to demonstrate possible bird-mediated colonization of lakes by the European perch ( Perca fluviatilis ). We studied a set of newly-formed and isolated artificial lakes that the public is either prohibited to access because of gravel extraction or allowed to access (mainly for angling). The motivating observation is that a large proportion of prohibited-access lakes (greater than 80%) were colonized by European perch even though stocking by anglers and managers never occurred. Three supplementary lines of evidence supported avian zoochory. First, European perch spawning occurs when waterfowl abundance is very high. Second, European perch lays sticky eggs at shallow depths where they can be eaten by waterfowls or attached to their bodies. Third, genetic analyses suggested that European perch actually migrate among lakes, and that distances moved match with daily flight range of foraging waterfowl. Together, multiple lines of evidence point to avian zoochory as a probable pathway for fish colonizing remote or newly-formed freshwater ecosystems.

Genetic diversity among and within populations of all species is necessary for people and nature to survive and thrive in a changing world. Over the past three years, commitments for conserving genetic diversity have become more ambitious and specific under the Convention on Biological Diversity's (CBD) draft post-2020 global biodiversity framework (GBF). This Perspective article comments on how goals and targets of the GBF have evolved, the improvements that are still needed, lessons learned from this process, and connections between goals and targets and the actions and reporting that will be needed to maintain, protect, manage and monitor genetic diversity. It is possible and necessary that the GBF strives to maintain genetic diversity within and among populations of all species, to restore genetic connectivity, and to develop national genetic conservation strategies, and to report on these using proposed, feasible indicators. ispartof: CONSERVATION GENETICS vol:24 issue:2 pages:181-191 ispartof: location:Netherlands status: published

The rapidly emerging field of macrogenetics focuses on analysing publicly accessible genetic datasets from thousands of species to explore large-scale patterns and predictors of intraspecific genetic variation. Facilitated by advances in evolutionary biology, technology, data infrastructure, statistics and open science, macrogenetics addresses core evolutionary hypotheses (such as disentangling environmental and life-history effects on genetic variation) with a global focus. Yet, there are important, often overlooked, limitations to this approach and best practices need to be considered and adopted if macrogenetics is to continue its exciting trajectory and reach its full potential in fields such as biodiversity monitoring and conservation. Here, we review the history of this rapidly growing field, highlight knowledge gaps and future directions, and provide guidelines for further research.

Biodiversity underlies ecosystem resilience, ecosystem function, sustainable economies, and human well-being. Understanding how biodiversity sustains ecosystems under anthropogenic stressors and global environmental change will require new ways of deriving and applying biodiversity data. A major challenge is that biodiversity data and knowledge are scattered, biased, collected with numerous methods, and stored in inconsistent ways. The Group on Earth Observations Biodiversity Observation Network (GEO BON) has developed the Essential Biodiversity Variables (EBVs) as fundamental metrics to help aggregate, harmonize, and interpret biodiversity observation data from diverse sources. Mapping and analyzing EBVs can help to evaluate how aspects of biodiversity are distributed geographically and how they change over time. EBVs are also intended to serve as inputs and validation to forecast the status and trends of biodiversity, and to support policy and decision making. Here, we assess the feasibility of implementing Genetic Composition EBVs (Genetic EBVs), which are metrics of within-species genetic variation. We review and bring together numerous areas of the field of genetics and evaluate how each contributes to global and regional genetic biodiversity monitoring with respect to theory, sampling logistics, metadata, archiving, data aggregation, modeling, and technological advances. We propose four Genetic EBVs: (i) Genetic Diversity; (ii) Genetic Differentiation; (iii) Inbreeding; and (iv) Effective Population Size (Ne ). We rank Genetic EBVs according to their relevance, sensitivity to change, generalizability, scalability, feasibility and data availability. We outline the workflow for generating genetic data underlying the Genetic EBVs, and review advances and needs in archiving genetic composition data and metadata. We discuss how Genetic EBVs can be operationalized by visualizing EBVs in space and time across species and by forecasting Genetic EBVs beyond current observations using various modeling approaches. Our review then explores challenges of aggregation, standardization, and costs of operationalizing the Genetic EBVs, as well as future directions and opportunities to maximize their uptake globally in research and policy. The collection, annotation, and availability of genetic data has made major advances in the past decade, each of which contributes to the practical and standardized framework for large-scale genetic observation reporting. Rapid advances in DNA sequencing technology present new opportunities, but also challenges for operationalizing Genetic EBVs for biodiversity monitoring regionally and globally. With these advances, genetic composition monitoring is starting to be integrated into global conservation policy, which can help support the foundation of all biodiversity and species' long-term persistence in the face of environmental change. We conclude with a summary of concrete steps for researchers and policy makers for advancing operationalization of Genetic EBVs. The technical and analytical foundations of Genetic EBVs are well developed, and conservation practitioners should anticipate their increasing application as efforts emerge to scale up genetic biodiversity monitoring regionally and globally. ispartof: BIOLOGICAL REVIEWS vol:97 issue:4 pages:1511-1538 ispartof: location:England status: published

A correction to this paper has been published: https://doi.org/10.1007/s10592-021-01376-9

The COVID-19 pandemic has heavily impacted academics' professional and personal lives, forcing many research groups (labs) to shift from an academic system primarily based on in-person work to an almost full-time remote workforce during lockdowns. Labs are generally characterized by a strong lab culture that underpins all research and social activities of its members. Lab culture traditionally builds on the pillars of in-person communication, knowledge sharing, and all social and professional activities that promote collaboration, team building, scientific productivity, and well-being. Here, we use the experience of our research group facing the COVID-19 pandemic to illustrate how proactively reinforcing lab culture and its positive outcomes have been essential to our lab when transitioning from an in-person to a remote lab environment, and through its ongoing evolution toward a hybrid remote/in-person model. We argue that the proactive promotion of lab culture in research groups can foster academic resilience during crises, helping research groups to maintain their capacity to conduct scientific activities while preserving a sustainable life/work balance and a healthy mental condition.

Millette et al. (Ecology Letters, 2020, 23:55-67) reported no consistent worldwide anthropogenic effects on animal genetic diversity using repurposed mitochondrial sequences. We describe limitations to this study, some of which are common to other macrogenetic studies, that may lead to misinterpretations and unintended consequences for conservation.

Teleost fishes interact with diverse microbial communities, playing crucial functions for host fitness. While gut microbiome has been extensively studied, skin microbiome has been overlooked. Specifically, there is no assessment of the relative impact of host and environmental factors on microbiome variability as well as neutral processes shaping fish skin microbiome. Here, we assessed the skin microbiome of a Siluriforme, the European catfish (Silurus glanis) sampled in four sites located in Southwestern France. We assessed the relative roles of individual features (body size and genetic background), local environment and neutral processes in shaping skin microbiome. Catfish skin microbiome composition was distinct to that of other freshwater fish species previously studied with high abundances of Gammaproteobacteria and Bacteroidetes. We found no effect of catfish individual genotype and body size on the structure of its associated skin microbiome. Geographical location was the best catfish skin microbiome structure predictor, together with neutral models of microbiome assembly.

International agreements such as the Convention on Biological Diversity (CBD) have committed to conserve, and sustainably and equitably use, biodiversity. The CBD is a vital instrument for global conservation because it guides 195 countries and the European Union in setting priorities and allocating resources, and requires regular reporting on progress. However, the CBD and similar policy agreements have often neglected genetic diversity. This is a critical gap because genetic diversity underlies adaptation to environmental change and ecosystem resilience. Here we aim to inform future policy, monitoring, and reporting efforts focused on limiting biodiversity loss by conducting the largest yet evaluation of how Parties to the CBD report on genetic diversity. A large, globally representative sample of 114 CBD National Reports was examined to assess reported actions, progress, values and indicators related to genetic diversity. Although the importance of genetic diversity is recognized by most Parties to the CBD, genetic diversity targets mainly addressed variation within crops and livestock (a small fraction of all species). Reported actions to conserve genetic diversity primarily concerned ex situ facilities and legislation, rather than monitoring and in situ intervention. The most commonly reported status indicators are not well correlated to maintaining genetic diversity. Lastly, few reports mentioned genetic monitoring using DNA data, indigenous use and knowledge of genetic diversity, or development of strategies to conserve genetic diversity. We make several recommendations for the post-2020 CBD Biodiversity Framework, and similar efforts such as IPBES, to improve awareness, assessment, and monitoring of genetic diversity, and facilitate consistent and complete reporting in the future.

ispartof: CONSERVATION GENETICS vol:22 issue:4 pages:533-536 status: published

ispartof: BIOLOGICAL CONSERVATION vol:253 status: published

Genetic diversity is critically important for all species-domesticated and wild- to adapt to environmental change, and for ecosystem resilience to extreme events. International agreements such as the Convention on Biological Diversity (CBD) have committed to conserve and sustainably and equitably use all levels of biodiversity-genes, species and ecosystems-globally. However, assessment and monitoring of genetic diversity are often overlooked, and there are large knowledge and policy gaps regarding genetic diversity conservation. In this study, we present the first quantitative analysis of genetic diversity assessments conducted by Parties to the CBD. We conducted a detailed, systematic analysis of 114 CBD 5th (submitted 2014) and 6th (submitted 2018) National Reports to quantitatively assess actions, progress on targets, values and indicators related to genetic diversity. First, we found that the importance of genetic diversity is recognised by most Parties to the CBD, and that recognition increased over time. However, genetic targets mainly addressed genetic diversity within cultivated plants, farm animals, and crop wild relatives, with little focus on other wild species. Also, actions for conserving genetic diversity primarily concerned ex-situ facilities and policy, rather than monitoring and intervention for maintaining genetic diversity in situ. The most commonly used indicators of genetic diversity status were the number of genetic resources in conservation facilities, number of threatened breeds, and Red List Index, which are not well correlated to genetic erosion in most species -- highlighting that genetic change is poorly monitored by current indicators. Lastly, analyses of genetic data observations, indigenous use and knowledge of genetic diversity, and strategies being developed and implemented to conserve genetic diversity are highly under-reported. We make several recommendations for the post-2020 CBD Biodiversity Framework to improve awareness, assessment, and monitoring, and facilitate consistent and complete reporting of progress of genetic diversity in future National Reports.Article Impact StatementAn analysis of genetic diversity in CBD National Reports neglects non-domesticated species and demonstrates need for sufficient indicators.

The 196 parties to the Convention on Biological Diversity (CBD) will soon agree to a post-2020 global framework for conserving the three elements of biodiversity (genetic, species, and ecosystem diversity) while ensuring sustainable development and benefit sharing. As the most significant global conservation policy mechanism, the new CBD framework has far-reaching consequences- it will guide conservation actions and reporting for each member country until 2050. In previous CBD strategies, as well as other major conservation policy mechanisms, targets and indicators for genetic diversity (variation at the DNA level within species, which facilitates species adaptation and ecosystem function) were undeveloped and focused on species of agricultural relevance. We assert that, to meet global conservation goals, genetic diversity within all species, not just domesticated species and their wild relatives, must be conserved and monitored using appropriate metrics. Building on suggestions in a recent Letter in Science (Laikre et al., 2020) we expand argumentation for three new, pragmatic genetic indicators and modifications to two current indicators for maintaining genetic diversity and adaptive capacity of all species, and provide guidance on their practical use. The indicators are: 1) the number of populations with effective population size above versus below 500, 2) the proportion of populations maintained within species, 3) the number of species and populations in which genetic diversity is monitored using DNA-based methods. We also present and discuss Goals and Action Targets for post-2020 biodiversity conservation which are connected to these indicators and underlying data. These pragmatic indicators and goals have utility beyond the CBD; they should benefit conservation and monitoring of genetic diversity via national and global policy for decades to come.\ud\ud Previous article in issue

International audience; Unraveling the relationship between demographic declines and genetic changes over time is of critical importance to predict the persistence of at-risk populations and to propose efficient conservation plans. This is particularly relevant in spatially struc- tured populations (i.e. metapopulations) in which the spatial arrangement of local populations can modulate both demographic and genetic changes. We used ten-year demo-genetic monitoring to test 1) whether demographic declines were associated with genetic diversity declines and 2) whether the spatial structure of a metapopula- tion can weaken or reinforce these demographic and genetic temporal trends. We continuously surveyed, over time and across their entire range, two metapopulations of an endemic freshwater fish species Leuciscus burdigalensis: one metapopulation that had experienced a recent demographic decline and a second metapopulation that was stable over time. In the declining metapopulation, the number of alleles rapidly decreased, the inbreeding coefficient increased, and a genetic bottleneck emerged over time. In contrast, genetic indices were constant over time in the stable metapopulation. We further show that, in the declining metapopulation, demographic and genetic declines were not homogeneously distributed across the metapopula- tion. We notably identify one local population situated downstream as a ‘reservoir’ of individuals and genetic variability that dampens both the demographic and genetic declines measured at the metapopulation level. We demonstrate the usefulness of long-term monitoring that combines both genetic and demographic parameters to understand and predict temporal population fluctuations of at-risk species living in a metapopulation context.

International audience; Species-genetic diversity correlations (SGDCs) have been investigated over a large spectra of organisms, which has greatly improved our understanding of parallel processes potentially driving both species and genetic diversity. However, there are still few studies comparing SGDCs (and underlying processes) for multiple species sampled over a single landscape. Here, focusing on freshwater fish sampled across a large river basin (the Garonne-Dordogne river basin, France), we combined a multi-species approach and causal analyses to (i) assess and compare both -SGDCs and -SGDCs among species, and (ii) infer processes underlying -SGDCs and -SGDCs. Genetic, intraspecific diversity was assessed for four sympatric fish (Barbatula barbatula, Gobio occitaniae, Phoxinus phoxinus and Squalius cephalus) using microsatellite markers. Species diversity was quantified as species richness using electric fishing, and environmental conditions were thoroughly described for 81 sites. We found significant and moderate positive -SGDCs for all four fish species, whereas -SGDCs were weaker in strength and positively significant for two of the four species. Causal analyses identified two common variables (geographical isolation and area of available habitats) underlying the -SGDC relationships. Although weak, we found that -SGDC correlations related to a direct relationship between taxonomic and genomic differentiation, and to the common influence of the abiotic environment acting as a filter on both species and alleles. Our study shows that similar ecological and evolutionary processes related to environmental filtering, migration, drift and colonisation history act for explaining both species and genetic diversity of fish communities.

Intraspecific diversity informs the demographic and evolutionary histories of populations, and should be a main conservation target. Although approaches exist for identifying relevant biological conservation units, attempts to identify priority conservation areas for intraspecific diversity are scarce, especially within a multi-specific framework. We used neutral molecular data on six European freshwater fish species (Squalius cephalus, Phoxinus phoxinus, Barbatula barbatula, Gobio occitaniae, Leuciscus burdigalensis and Parachondrostoma toxostoma) sampled at the riverscape scale (i.e. the Garonne-Dordogne River basin, France) to determine hot- and cold-spots of genetic diversity, and to identify priority conservation areas using a systematic conservation planning approach. We demonstrate that systematic conservation planning is efficient for identifying priority areas representing a predefined part of the total genetic diversity of a whole landscape. With the exception of private allelic richness, classical genetic diversity indices (allelic richness, genetic uniqueness) were poor predictors for identifying priority areas. Moreover, we identified weak surrogacies among conservation solutions found for each species, implying that conservation solutions are highly species-specific. Nonetheless, we showed that priority areas identified using intraspecific genetic data from multiple species provide more effective conservation solutions than areas identified for single species or on the basis of traditional taxonomic criteria.

International audience; Emerging pathogens constitute a severe threat for human health and biodiversity. Determining the status (native or non-native) of emerging pathogens, and tracing back their spatio-temporal dynamics, is crucial to understand the eco-evolutionary factors promoting their emergence, to control their spread and mitigate their impacts. However, tracing back the spatio-temporal dynamics of emerging wildlife pathogens is challenging because (i) they are often neglected until they become sufficiently abundant and pose socio-economical concerns and (ii) their geographical range is often little known. Here, we combined classical population genetics tools and approximate Bayesian computation (i.e. ABC) to retrace the dynamics of Tracheliastes polycolpus, a poorly documented pathogenic ectoparasite emerging in Western Europe that threatens several freshwater fish species. Our results strongly suggest that populations of T. polycolpus in France emerged from individuals originating from a unique genetic pool that were most likely introduced in the 1920s in central France. From this initial population, three waves of colonization occurred into peripheral watersheds within the next two decades. We further demonstrated that populations remained at low densities, and hence undetectable, during 10 years before a major demographic expansion occurred, and before its official detection in France. These findings corroborate and expand the few historical records available for this emerging pathogen. More generally, our study demonstrates how ABC can be used to determine the status, reconstruct the colonization history and infer key evolutionary parameters of emerging wildlife pathogens with low data availability, and for which samples from the putative native area are inaccessible.

International audience; Describing, understanding and predicting the spatial distribution of genetic diversity is a central issue in biological sciences. In river landscapes, it is generally predicted that neutral genetic diversity should increase downstream, but there have been few attempts to test and validate this assumption across taxonomic groups. Moreover, it is still unclear what are the evolutionary processes that may generate this apparent spatial pattern of diversity. Here, we quantitatively synthesized published results from diverse taxa living in river ecosystems, and we performed a meta-analysis to show that a downstream increase in intraspecific genetic diversity (DIGD) actually constitutes a general spatial pattern of biodiversity that is repeatable across taxa. We further demonstrated that DIGD was stronger for strictly waterborne dispersing than for overland dispersing species. However, for a restricted data set focusing on fishes, there was no evidence that DIGD was related to particular species traits. We then searched for general processes underlying DIGD by simulating genetic data in dendritic-like river systems. Simulations revealed that the three processes we considered (downstream-biased dispersal, increase in habitat availability downstream and upstream-directed colonization) might generate DIGD. Using random forest models, we identified from simulations a set of highly informative summary statistics allowing discriminating among the processes causing DIGD. Finally, combining these discriminant statistics and approximate Bayesian computations on a set of twelve empirical case studies, we hypothesized that DIGD were most likely due to the interaction of two of these three processes and that contrary to expectation, they were not solely caused by downstream-biased dispersal.

International audience; Landscape features notoriously affect spatial patterns of biodiversity. For instance, in dendritic ecological networks (such as river basins), dendritic connectivity has been proposed to create unique spatial patterns of biodiversity. Here, we compared genetic datasets simulated under a lattice-like, a dendritic and a circular landscape to test the influence of dendritic connectivity on neutral genetic diversity. The circular landscape had a level of connectivity similar to that of the dendritic landscape, so as to isolate the influence of dendricity on genetic diversity. We found that genetic diversity and differentiation varied strikingly among the three landscapes. For instance, the dendritic landscape generated higher total number of alleles and higher global F-st than the lattice-like landscape, and these indices also varied between the dendritic and the circular landscapes, suggesting an effect of dendricity. Furthermore, in the dendritic landscape, allelic richness was higher in highly connected demes (e.g. confluences in rivers) than in low-connected demes (e.g. upstream and downstream populations), which was not the case in the circular landscape, hence confirming the major role of dendricity. This led to bell-shaped distributions of allelic richness along an upstream-downstream gradient. Conversely, genetic differentiation (F-st) was lower in highly than in low-connected demes (which was not observed in circular landscape), and significant patterns of isolation by distance (IBD) were also observed in the dendritic landscape. We conclude that in dendritic networks, the combined influence of dendricity and connectivity generates unique spatial patterns of neutral genetic diversity, which has implications for population geneticists and conservationists.

International audience; Identifying landscape features that affect functional con- nectivity among populations is a major challenge in fundamental and applied sciences. Landscape genetics combines landscape and genetic data to address this issue, with the main objective of disentangling direct and indirect relationships among an intricate set of variables. Causal modeling has strong potential to address the complex nature of land- scape genetic data sets. However, this statistical approach was not ini- tially developed to address the pairwise distance matrices commonly used in landscape genetics. Here, we aimed to extend the applicability of two causal modeling methods—that is, maximum-likelihood path analysis and the directional separation test—by developing statistical approaches aimed at handling distance matrices and improving func- tional connectivity inference. Using simulations, we showed that these approaches greatly improved the robustness of the absolute (using a frequentist approach) and relative (using an information-theoretic ap- proach) ␣ts of the tested models. We used an empirical data set combin- ing genetic information on a freshwater ␣sh species (Gobio occitaniae) and detailed landscape descriptors to demonstrate the usefulness of causal modeling to identify functional connectivity in wild populations. Speci␣cally, we demonstrated how direct and indirect relationships in- volving altitude, temperature, and oxygen concentration in␣uenced within- and between-population genetic diversity of G. occitaniae.

SUMMARY 1. Molecular genetic techniques have been used in freshwater biology for more than 30 years. Early work focussed on studies of population structure, systematics and taxonomy. More recently, the range of studies has broadened to include ecology and adaptation. Advances in analytical methods and in technology (e.g. next-generation sequencing) and decreasing costs of data production ensure that the field will continue to develop and broaden in scope. 2. At least three factors make the application of molecular techniques to freshwater biology exciting. First, the highly variable nature of many aquatic habitats makes them excellent models for the study of environmental change on ecological and evolutionary time scales. Second, the mature state of the field of freshwater biology provides an extensive foundation of ecological knowledge of freshwater organisms and their distinct adaptations. Third, the methodological advances allow researchers to focus more on merging molecular and ecological research and less on designing studies around technical limitations. 3. We identified eight research areas in freshwater biology in which the integration of molecular and ecological approaches provides exceptional opportunities. The list is not exhaustive, but considers a broad range of topics and spans the continuum from basic to applied research. The areas identified use a combination of natural, experimental and in silico approaches. 4. With advancing molecular techniques, freshwater biology is in an unusually strong position to link the genetic basis and ecological importance of adaptations across a wide range of taxa, ecosystems and spatiotemporal scales. Our aim was to identify opportunities for the integration of molecular and ecological approaches, to motivate greater collaboration and crossover, and to promote exploitation of the synergies of bridging ecological and evolutionary freshwater research.

Prioritizing and making efficient conservation plans for threatened populations requires information at both evolutionary and ecological timescales. Nevertheless, few studies integrate multidisciplinary approaches, mainly because of the difficulty for conservationists to assess simultaneously the evolutionary and ecological status of populations. Here, we sought to demonstrate how combining genetic and demographic analyses allows prioritizing and initiating conservation plans. To do so, we combined snapshot microsatellite data and a 30-year-long demographic survey on a threatened freshwater fish species (Parachondrostoma toxostoma) at the river basin scale. Our results revealed low levels of genetic diversity and weak effective population sizes (

Population structure can significantly affect genetic-based demographic inferences, generating spurious bottleneck-like signals. Previous studies have typically assumed island or stepping-stone models, which are characterized by symmetric gene flow. However, many organisms are characterized by asymmetric gene flow. Here, we combined simulated and empirical data to test whether asymmetric gene flow affects the inference of past demographic changes. Through the analysis of simulated genetic data with three methods (i.e. bottleneck, M-ratio and msvar), we demonstrated that asymmetric gene flow biases past demographic changes. Most biases were towards spurious signals of expansion, albeit their strength depended on values of effective population size and migration rate. It is noteworthy that the spurious signals of demographic changes also depended on the statistical approach underlying each of the three methods. For one of the three methods, biases induced by asymmetric gene flow were confirmed in an empirical multispecific data set involving four freshwater fish species (Squalius cephalus, Leuciscus burdigalensis, Gobio gobio and Phoxinus phoxinus). However, for the two other methods, strong signals of bottlenecks were detected for all species and across two rivers. This suggests that, although potentially biased by asymmetric gene flow, some of these methods were able to bypass this bias when a bottleneck actually occurred. Our results show that population structure and dispersal patterns have to be considered for proper inference of demographic changes from genetic data. Agence de l'Eau Adour-Garonne; Génopole Toulouse; Ministère de l'Enseignement Supérieur et de la Recherche; Laboratoire d’Excellence (LABEX) entitled TULIP (ANR -10-LABX- 41).