Recombination suppressors and the evolution of new species.

Chromosomal rearrangements are often the only apparent difference between closely related species, although it is not clear whether they are a cause or a by-product of speciation. We suggest that changes in the pattern of recombination may provide a link between chromosomal rearrangements and speciation. In models of speciation by sexual selection and by reinforcement, recombination is a major barrier to the formation of new species, primarily because it opposes the establishment of linkage disequilibrium. Here we show that in both the Felsenstein (1981) and Kirkpatrick (1982) models, a recombination suppressor is able to enhance the processes leading to speciation and increase its own frequency in the population.