Meiotic Drive and Speciation.

Meiotic drive is the biased transmission of alleles from heterozygotes, contrary to Mendel's laws, and reflects intragenomic conflict rather than organism-level Darwinian selection. Theory has been developed as to how centromeric properties can promote female meiotic drive and how conflict between the X and Y chromosomes in males can promote male meiotic drive. There are empirical data that fit both the centromere drive and sex chromosome drive models. Sex chromosome drive may have relevance to speciation through the buildup of Dobzhansky-Muller incompatibilities involving drive and suppressor systems, studied particularly in Drosophila. Centromere drive may promote fixation of chromosomal rearrangements involving the centromere, and those fixed rearrangements may contribute to reproductive isolation, studied particularly in the house mouse. Genome-wide tests suggest that meiotic drive promotes allele fixation with regularity, and those studying the genomics of speciation need to be aware of the potential impact of such fixations on reproductive isolation. New species can originate in many different ways (including multiple factors acting together), and a substantial body of work on meiotic drive point to it being one of the processes involved.