Centimorgan

In genetics, a centimorgan (abbreviated cM) is a unit of recombinant frequency. It is often used to imply distance along a chromosome. The centimorgan is equal to a 1% chance that a marker at one genetic locus on a chromosome will be separated from a marker at a second locus due to crossing over in a single generation. In human beings, one centimorgan is equivalent, on average, to one million base pairs. The centimorgan was named in honor of geneticist Thomas Hunt Morgan by his student Alfred Henry Sturtevant. Note that the parent unit of the centimorgan, the morgan, is never used.

A map unit (abbreviated m.u.) is synonymous with centimorgan.

See also

• Genetic recombination
• Chromosomal crossover