Congruence between the sexes in preexisting receiver responses

Preexisting receiver biases have been shown to affect how femalesdetect and respond to new conspecific traits in a mate choicecontext. Although preexisting biases have often been discussedin the context of female mate choice, these biases need notbe sex limited. In the genus Xiphophorus, swordtail males possessa sexually selected trait, the sword. Here I consider evidencethat the state of a bias favoring sworded conspecifics maybe generally shared by the sexes in taxa in which the swordhas not arisen. In three unsworded species of poeciliid fishes,both males and females prefer members of the other sex withswords. In a fourth species, males and females share the absenceof a response to a sword. This congruity between the sexessuggests that response biases may not be sex limited and thatthe sexes could historically share common mechanisms producingshared mating responses. Alternatively, selection may tendto result in parallel changes in biases in the sexes. Thiswork expands our understanding of receiver biases by usinga phylogenetic approach to examine whether biases are historicallyshared by the sexes and suggests that there can be generalcongruence between the sexes in such biases.