Interaction of Selection and Recombination

Abstract

Each of two separate loci on a chromosome may be occupied by one of two alternative alleles. The genotypic frequencies depend on both selection and recombination. The crossover frequency will itself be modified by selection. If this latter process is slow compared with the former, we may envisage the population as passing through a succession of equilibrium states. The stability of these states is analysed and it is shown that changes in crossover frequency may lead to (1) sudden shifts in the frequencies of the various chromosomal types, and (2) a split into two different populations. This latter case provides a new model for incipient speciation.