Homologous recombination occurs most famously during the formation of egg and sperm cells, when the two sets of chromosomes we inherit from our parents are pared down to just one, to be combined with a second set during sexual reproduction. In this process of elimination, cells select a blend of the paternal and maternal chromosomes; each pair of chromosomes engage in their own version of sex, exchanging large chunks of DNA in a way that increases genetic diversity.
