Reproductive fitness and longevity in Drosophila melanogaster.

It has been suggested that senescence could have evolved by selection of genes with beneficial effects early in life and detrimental ones later in life (pleiotropy theory of the evolution of senescence). To test that theory, the egg production of 322 females of the Oregon strain of Drosophila melanogaster was recorded daily throughout their life. At the individual level, no relation could be detected between early components of fitness and longevity. For the time being it appears that there are no unequivocal reasons to accept the pleiotropy theory of the evolution of senescence.