Pleiotropy and life history evolution in Drosophila melanogaster: uncoupling life span and early fecundity.

Populations of Drosophila melanogaster that have been artificially selected for late age of reproduction evolve longer life spans and, in some cases, reduced early fecundity. The negative correlation is widely interpreted as evidence of antagonistic pleiotropy. Here, we show that the correlation breaks down in recombinant genomes. A major quantitative trait locus that increases adult life span by 20% has no detectable effect on early fecundity. Several recombinant genotypes are superflies, exhibiting both elevated early fecundity and long life. The genetic correlation of early fecundity and life span is not different from zero, while the midlife fecundity correlation is positive and statistically significant, suggesting age-specific adaptation. The results are not consistent with a dominant role for negative pleiotropy, but can be understood in terms of a mixture of pleiotropic and recombining nonpleiotropic elements. Life span and early fecundity can be genetically uncoupled.