Congruence between the sexes in preexisting receiver responses

Preexisting receiver biases have been shown to affect how females detect and respond to new conspecific traits in a mate choice context. Although preexisting biases have often been discussed in the context of female mate choice, these biases need not be sex limited. In the genus Xiphophorus, swordtail males possess a sexually selected trait, the sword. Here I consider evidence that the state of a bias favoring sworded conspecifics may be generally shared by the sexes in taxa in which the sword has not arisen. In three unsworded species of poeciliid fishes, both males and females prefer members of the other sex with swords. In a fourth species, males and females share the absence of a response to a sword. This congruity between the sexes suggests that response biases may not be sex limited and that the sexes could historically share common mechanisms producing shared mating responses. Alternatively, selection may tend to result in parallel changes in biases in the sexes. This work expands our understanding of receiver biases by using a phylogenetic approach to examine whether biases are historically shared by the sexes and suggests that there can be general congruence between the sexes in such biases. Copyright 2002.