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Nature 406, 67 - 70 (2000) © Macmillan Publishers Ltd.
Negative genetic correlation between male sexual attractiveness
and survival
ROBERT BROOKS
School of Tropical Biology, James Cook University, Townsville 4811,
Queensland, Australia
Correspondence and requests for materials should be addressed to R.B.
(e-mail: rob.brooks@jcu.edu.au).
Indirect selection of female mating preferences may result from a genetic
association between male attractiveness and offspring fitness. The offspring
of attractive males may have enhanced growth, fecundity, viability or
attractiveness. However, the extent to which attractive males bear genes
that reduce other fitness components has remained unexplored. Here I
show that sexual attractiveness in male guppies (Poecilia reticulata)
is heritable and genetically correlated with ornamentation. Like ornamentation,
attractiveness may be substantially Y-linked. The benefit of mating
with attractive males, and thus having attractive sons, is opposed by
strong negative genetic correlation between attractiveness and both
offspring survival and the number of sons maturing. Such correlations
suggest either antagonistic pleiotropy between attractiveness and survival
or linkage disequilibrium between attractive and deleterious alleles.
The presence of many colour pattern genes on or near the non-recombining
section of the Y chromosome may facilitate the accumulation of deleterious
mutations by genetic hitch-hiking. These findings show that genes enhancing
sexual attractiveness may be associated with pleiotropic costs or heavy
mutational loads. [snip]
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