Heroic heirs: evidence for sexy and competitive sons

Leks are the quintessential example of female mate choice, yet male-male
interactions at leks may predominate. How, and how much, female mate
choice versus male-male competition contribute to precopulatory sexual
selection, including whether they are aligned or antagonistic, matters to
theory and our understanding of how selection acts on both males and
females. For example, if male-male competition predominates and selection
favours harmful, dominant males, then female and population fitness may be
compromised. Here, using Drosophila melanogaster, we performed two
artificial selection experiments in parallel where we altered selection to
favour male-male competition (selection for winners and losers in
multi-male competition trials) or female mate choice (selection for
winners and losers in single-male latency trials). After seven generations
of selection, males from winner-selected lines had higher mating success
than males from loser-selected lines in both competitive and
non-competitive arenas. Our results support the idea that the outcomes of
male-male competition and female choice are aligned or that one process
dominates the other.