genetic recombination

If your mother carries one mix of gene versions and your father another, recombination is what lets you inherit a fresh blend rather than an exact copy of either parent's chromosomes. It is the reshuffling of alleles into new combinations as they pass from one generation to the next.

In sexually reproducing organisms, recombination comes from two sources during meiosis. Crossing over swaps segments between homologous chromosomes, mixing alleles that sit on the same chromosome. Independent assortment lets each homologous pair line up and separate at random, mixing alleles that sit on different chromosomes. Fertilization then combines two already-recombined gametes.

More broadly, geneticists use recombination to mean any process that joins genetic material into combinations not present in the parents, including homologous recombination used in DNA repair and the laboratory creation of recombinant DNA. In all cases the common thread is the rearrangement of existing sequences into something new.