Song and morphology data for selection by females on male Gryllus firmus

Female preference exerts selection on male traits. How such preferences
affect male traits, how female preferences change and the genetic
correlation between male traits and female preference were examined by an
experiment in which females were either mated to males they preferred (S
lines) or to males chosen at random from the population (R lines).
 Female preference was predicted to increase the time spent
calling by males.  Thirteen other song components were measured.
 Preference for individual traits was greatest for time spent
calling(CALL), volume(VOL) and chirp rate(CHIRP) but the major
contributors in the multivariate function were CALL and CHIRP, the
univariate influence of VOL arising from correlations to these traits.
 Estimation of β, the standardized selection differential, for
CALL resulting from female preference showed that it was under strong
direct selection.  However, contrary to prediction, CALL did not
change over the course of the experiment whereas VOL, CHIRP and other song
components did.  Simulation of the experiment using the estimated
G matrix showed that lack of change in CALL resulted from indirect genetic
effects negating direct effects.  Changes in song components were
largely due to indirect effects.  This experiment showed that
female preference may exert strong selection on traits but how they
respond to such selection will depend greatly upon the G matrix.
 As predicted, female preference declined in the R lines.
 The genetic correlations between preference and preferred traits
did not decline significantly more in the R lines, suggesting correlations
resulted from both linkage disequilibrium and pleiotropy.