Developmental time and adult longevity in two strains of Drosophila melanogaster in a constant low-stress environment.

This study examines the life spans of wild type flies (Sevelen strain, n = 2991) and post-replication DNA repair-deficient flies (mei-41D5, n = 1607) as members of age-synchronized birth cohorts and as members of full sibships. Flies were individually housed from the time they were laid as eggs until they died as imagoes; environmental conditions were constant throughout the life span of these virgins. In this minimal stress experiment, developmental time and imaginal longevity were negligibly correlated (r = -0.09 to -0.25), even though developmental time was canalized at different levels in both strains. Previous research involving environmental perturbations during the life span of Drosophila (e.g. temperature, diet, population density) has demonstrated significant strong correlations, mostly positive, between developmental time and adult longevity. We have demonstrated that the duration of development and aging are not coupled in the absence of such stresses. We therefore suggest that related changes in the duration of the pre-imaginal and the adult stages of the lifecycle of Drosophila may have evolved through adaptation to environmental stresses.