Meiotic drive is a type of intragenomic conflict, whereby one or more loci within a genome will affect a manipulation of the meiotic process in such a way as to favor the transmission of one or more alleles over another, regardless of its phenotypic expression. More simply, meiotic drive is when one copy of a gene is passed on to offspring more than the expected 50% of the time.
According to Buckler et al., "Meiotic drive is the subversion of meiosis so that particular genes are preferentially transmitted to the progeny. Meiotic drive generally causes the preferential segregation of small regions of the genome".
A recent study by John Didion and Fernando Pardo-Manuel de Villena found evidence of a gene in mice (r2d2 – responder to meiotic drive 2) that is passed on more than 50% of the time. Gregor Mendel's First and Second Laws (the law of segregation and the law of independent assortment) tell us that there is a random chance of each allele being passed on to offspring, but selfish genes seem to break these laws.