A comparison of inbreeding Depression in Tropical and Widespread Drosophila Species

The evolutionary history of widespread and specialized species is likely to cause a different genetic architecture of key ecological traits in the two species group. This may affect how these two groups respond to inbreeding. Here we investigate inbreeding effects in traits related to performance in 5 widespread and 5 tropical restricted species of Drosophila with aim of testing whether the two species groups suffered differently from inbreeding depression. The traits investigated wwere egg-to-adult viability, develpmental time and resistance to heat, vold and desiccation. Our results showed that levels of inbreeding depression were species and trait specific and did not differ between the species groups for stress resistance traits. However, for the life history traits developmental time and egg-to-adult viability, more inbreeding depression was observed in the tropical species. The results reported suggest that for life history traits tropical species of Drosophila will suffer more from inbreeding depression than widespread species in case of increases in the rate of inbreeding e.g. due to declines in population sizes.