Sexual selection: when to expect trade-offs.
Empirical evidence is mixed for interspecific trade-offs in investment among sexually selected traits. One important reason may be the way resources are allocated among species. Consider a set of species that obtains the same fitness pay-off for investment in song or plumage. Simulations where resources were normally distributed among species revealed significant trade-offs between song and plumage ( ± s.d. of r = -0.54 ± 0.06). However, simulations where resources were distributed in a negative binomial fashion usually produced positive correlations (r = 0.11 ± 0.09). Repeating simulations on three published studies that concomitantly quantified elaboration of song and plumage indicated that trade-offs are likely, although these analyses make assumptions that require further evaluation. Moreover, there are currently too few empirical distributions to make generalizations about the likelihood of interspecific trade-offs in sexually selected traits.
Shutler
Dave
D
Department of Biology, Acadia University, Wolfville, Nova Scotia B4P 2R6, Canada. dave.shutler@acadiau.ca
D000818:Animals; D005075:Biological Evolution; D001717:Birds / Q000235:genetics* / Q000502:physiology*; D017753:Ecosystem; D008954:Models, Biological; D012641:Selection, Genetic; D012727:Sex Characteristics