Abstracts (first author)
Inference of the demographic history of Drosophila subobscura using Approximate Bayesian Computation: a multilocus analysis along chromosome J
Understanding the forces that control genetic variation in natural populations has been a major challenge for evolutionary biologists. Drosophila subobscura is a member of the obscura group that is widely distributed in the Paleartic region and presents a rich chromosomal polymorphism. Although this species has been extensively studied in relation to chromosomal inversion polymorphism, little is known about its demographic history. Multilocus studies provide an excellent opportunity to determine whether demographic factors have shaped the genetic variation observable in natural populations. In order to infer the demographic history of D. subobscura from the Paleartic area through Approximate Bayesian Computation (ABC), we sequenced and analyzed 16 non-coding regions distributed along the J chromosome in regions not affected by chromosomal inversions. In the 16 regions, the frequency spectrum was shifted towards an excess of low frequency variants, which led us to explore different simple scenarios including a final population expansion. Even if scarce, existing information on climatic changes as well as on recombination rates in the species under study was used to establish prior distributions for those parameters defining each model. Contrasting the different models through ABC analysis will provide new insides into the evolutionary history of D. subobscura based on an ample dataset of independently evolving loci not affected by chromosomal polymorphism.