A centimorgan is a unit of genetic material in a chromosome that can be used to measure relatedness of 2 individuals. It is not an actual physical distance. It was named after Thomas Hunt Morgan.
A parent and child will share about 3,400 centimorgans of DNA, with the amount decreasing as people become more separated on a genetic tree.
A centimorgan represents:
(1) about 1 million base pairs in humans
(2) the length of genetic material that has an expected probability (that an intervening crossover in a single generation will occur during meiosis) of 1%.
number of centimorgans for a probability of recombination =
