Data from: A multivariate analysis of genetic variation in the advertisement call of the gray treefrog, Hyla versicolor

Genetic variation in sexual displays is crucial for an evolutionary
response to sexual selection, but can be eroded by strong selection.
Identifying the magnitude and sources of additive genetic variance
underlying sexually-selected traits is thus an important issue in
evolutionary biology. We conducted a quantitative genetics experiment with
gray treefrogs (Hyla versicolor) to investigate genetic variances and
covariances among features of the male advertisement call. Two
energetically-expensive traits showed significant genetic variation: call
duration, expressed as number of pulses per call, and call rate,
represented by its inverse, call period. These two properties also showed
significant genetic covariance, consistent with an energetic constraint to
call production. Combining the genetic variance-covariance matrix with
previous estimates of directional sexual selection imposed by female
preferences predicts a limited increase in call duration but no change in
call rate despite significant selection on both traits. In addition to
constraints imposed by the genetic covariance structure, an evolutionary
response to sexual selection may also be limited by high energetic costs
of long-duration calls and by preferences that act most strongly against
very short-duration calls. Meanwhile, the persistence of these preferences
could be explained by costs of mating with males with especially
unattractive calls.