Dissecting selection on female mating preferences during secondary contact.

Population-specific preferences involved in premating isolation may be based on several different types of mating cues. Here, we compare the rates of spread of 12 different mating preferences that reflect preferences for local adaptation, male condition, and reinforcement. We introduce methods to dissect the components of the rate of spread to determine why certain mating preferences spread more quickly than others. We confirm the result that female preferences based on population-specific markers alone always spread faster than female preferences based only on a single local adaptation locus, regardless of the strength of natural selection on hybrid incompatibility. However, we find that this occurs for different reasons depending on the strength of selection against hybrids. Female preferences based on total male condition also achieved high rates of spread, suggesting that preferences for condition-dependent male displays may evolve under reinforcement scenarios.