Thermal adaptation of life history traits in the Drosophila melanogaster group

Thermal adaptation is typically detected by examining the tolerance to extreme temperatures in a few populations within a single life stage. However, the extent to which adaptation occurs among many different populations might depend on the tolerance of multiple life stages and the average temperature range that the population experiences. Here, I examined adaptation to local temperature conditions in four species of fruit flies, including a cosmopolitan species, Drosophila melanogaster, and three species with geographically small-sized ranges, D. nepalensis, D. sechellia, and D. mauritiana. The cosmopolitan species showed adaptation to native temperatures during the larval and adult life stages, but the species with geographically restricted ranges differed in their responses to temperature changes during all life stages. Therefore, species with restricted ranges are more sensitive to temperature shifts than widespread species, and within species there are differences in tolerance among populations and life stages