Data from: Runaway sexual selection leads to good genes

Mate choice and sexual displays are widespread in nature, but their
evolutionary benefits remain controversial. Theory predicts these traits
can be favored by runaway sexual selection, in which preference and
display reinforce one another due to genetic correlation; or by good genes
benefits, in which mate choice is advantageous because extreme displays
indicate a well-adapted genotype. However, these hypotheses are not
mutually exclusive, and the adaptive benefits underlying mate choice can
themselves evolve. In particular, examining how and why sexual displays
become indicators of good genes is challenging in natural systems. Here,
we use experimental evolution in "digital organisms" to
demonstrate the origins of condition-dependent indicator displays
following their spread due to a runaway process. Surprisingly,
handicap-like costs are not necessary for displays to become indicators of
male viability. Instead, a pleiotropic genetic architecture underlies both
displays and viability. Runaway sexual selection and good genes benefits
should thus be viewed as interacting mechanisms that reinforce one
another.