Competition and genotypic variability in Drosophila melanogaster.

It has been claimed that in competitive conditions larval viabilities of Drosophila melanogaster depend on the similarity of genotypes coexisting. Two types of experimental populations were established: homogeneous (low genotypic variability) and heterogeneous (high genotypic variability). Under conditions of moderate larval competition productivity was similar, in each although the developmental time was shorter in the heterogeneous series. Under conditions of high larval competition the productivity of heterogeneous populations exceeded that of the homogeneous and attained the adult stage in shorter period of time.