Studies focusing on geographical genetic patterns of commensal species and on human history complement each other and provide proxies to trace common colonization events. On Madagascar, the unintentional introduction and spread of the commensal species R attus rattus by people may have left a living clue of human colonization patterns and history. In this study, we addressed this question by characterizing the genetic structur...

Genome scans using amplified fragment length polymorphism (AFLP) markers became popular in nonmodel species within the last 10 years, but few studies have tried to characterize the anonymous outliers identified. This study follows on from an AFLP genome scan in the black rat ( Rattus rattus ), the reservoir of plague ( Yersinia pestis infection) in Madagascar. We successfully sequenced 17 of the 22 markers previously shown to...

The black rat ( Rattus rattus ) is the main reservoir of plague ( Yersinia pestis infection) in Madagascar’s rural zones. Black rats are highly resistant to plague within the plague focus (central highland), whereas they are susceptible where the disease is absent (low altitude zone). To better understand plague wildlife circulation and host evolution in response to a highly virulent pathogen, we attempted to determine genetic...

Using the same set of microsatellite markers, we compared the population genetic structure of two Mastomys species, one being exclusively commensal in southeastern Senegal, and the other being continuously distributed outside villages in this region. Both species were sampled in the same landscape context and at the same spatial scale. According to the expectations based on the degree of habitat patchiness (which is higher for...

The evolutionary importance of hybridization in wild plants and animals has become increasingly widely recognized in the last decade. In practical terms, hybridization provides an exceptionally tough set of problems for conservation biologists. We illustrate this in a case study of two Carabidae species widely used to evaluate the impact of human activities on biodiversity. These two species live in a complex mosaic of sympatr...

Habitat specialist species are supposed to be more susceptible to variations in local environmental characteristics than generalists. To test this hypothesis, we conducted a comparative analysis on abundance and genetic diversity of forest carabids differing in their habitat requirements. Four species were sampled in forests characterized by abiotic, landscape and biotic environmental variables. A statistical framework based o...

Comprising four allopatric subspecies that exhibit various grades of ant–plant interactions, from diffuse to obligate and symbiotic associations, the Leonardoxa africana complex (Fabaceae, Caesalpinioideae) provides a good opportunity to investigate the evolutionary history of ant–plant mutualisms. A previous study of the L. africana complex based on chloroplast DNA noncoding sequences revealed a lack of congruence between cla...

Using microsatellite markers, we compared the genetic structure of populations of two carabid species, one described as a generalist (commonly found in forest and in open habitats) and the other known as a forest specialist. Both species were sampled in the same forest plots, which were separated from each other by either open or forested areas. At the local scale considered (13.6 km separating the most distant plots), genetic...