Abstract
Exposure of diurnal animals to constant light for extended periods dampens the clock gene circadian rhythms, which in turn affect the life history traits. However, animals are expected to maintain some form of rhythm for the body to function effectively. In this study, we used three populations of Drosophila melanogaster that were maintained under constant light for 312 generations. We entrained three other populations (derived from those in constant light for 312 generations) to 12L:12D cycles. The adaptive evolution under aperiodic conditions has compromised on longevity and fecundity- two most important fitness traits for an iteroparous species.