Data from: Landscape does matter: disentangling founder effects from natural and human-aided post-introduction dispersal during an ongoing biological invasion

Environmental features impacting the spread of invasive species after introduction can be assessed using population genetic structure as a quantitative estimation of effective dispersal at the landscape scale. However, in the case of an ongoing biological invasion, deciphering whether genetic structure represents landscape connectivity or founder effects is particularly challenging. We examined the modes of dispersal (natural and human-aided) and the factors (landscape or founders history) shaping genetic structure in range edge invasive populations of the Asian tiger mosquito, Aedes albopictus, in the region of Grenoble (Southeast France). Based on detailed occupancy-detection data and environmental variables (climatic, topographic, land-cover), we modelled A. albopictus potential suitable area and its expansion history since first introduction. The relative role of dispersal modes was estimated using biological dispersal capabilities and landscape genetics approaches using genome-wide SNP dataset. We demonstrate that both natural and human-aided dispersal have promoted the expansion of populations. Populations in diffuse urban areas, representing highly suitable habitat for A. albopictus, tend to disperse less, while roads facilitate long-distance dispersal. Yet demographic bottlenecks during introduction played a major role in shaping the genetic variability of these range edge populations. The present study is one of the few investigating the role of founder effects and ongoing expansion processes in shaping spatial patterns of genetic variation in an invasive species at the landscape scale. The combination of several dispersal modes and large proportions of continuous suitable habitats for A. albopictus promoted range filling of almost its entire potential distribution in the region of Grenoble only few years after introduction.Funding provided by: Labex OSUG@2020 *Crossref Funder Registry ID: Award Number: ANR10 LABX56Funding provided by: Labex OSUG@2020Crossref Funder Registry ID: Award Number: ANR10 LABX56The data comprise two SNP datasets obtained from double digest restriction associated DNA sequencing (ddRADseq): - Dataset 1 (1,112 SNPs; 411 individuals) used for inferring the origin of Aedes albopictus invasive populations in the region of Grenoble, France (ABC reconstruction of colonization routes) - Dataset 2 (1,960 SNPs; 269 individuals) used for identiyfing the geographical and landscape features impacting population connectivity The datasets are in VCF format. The position (CHROM), loci (LOCI ID), position (POS), reference allele (REF) and alternative allele (ALT) are given for each SNP (one SNP per ddRAD locus). The genotypes are encoded as "0|0": homozygote REF; "0|1": heterozygote; "1|1": homozygote ALT; ".|.": missing. The raw sequences analyzed in the study are available in the European Nucleotide Archive repository (http://www.ebi.ac.uk/ena)