Abstract
Two of Mendel's three laws were quickly discarded as information on the organization and transmission of genes accumulated at the beginning of this century, but his law of segregation has shown remarkable staying power. In fact, within most of population genetic theory for sexual diploids is buried the tacit assumption that heterozygous alleles are represented in gametes in a 1:1 ratio. Nevertheless, there is a small, but important, group of genetic systems that subvert the law of segregation, and show 'meiotic drive'.
