The mapping functions of Haldane and of Kosambi allow conversion between mapping units and recombination fractions used in genetic maps.
Features:
(1) Haldane's function does not allow for genetic interference
(2) Kosambi's function assumes genetic interference
Haldane's Function
map units (Haldane) in centiMorgans =
= (-0.5) * (LN(1 - (2 * (recombination fraction))))
recombination fraction =
= 0.5 * (1 - (EXP((-2) * (map units Haldane))))
where:
• The unit of measurement for genetic maps is the centimorgan (cM).
Kosambi's Function
map units (Kosambi) in centiMorgans =
= (0.25) * (LN((1 + (2 * (recombination fraction))) / (1 - (2 * (recombination fraction)))))
recombination fraction =
= 0.5 * (((EXP(4 * (map units Kosambi))) - 1) / ((EXP(4 * (map units Kosambi))) + 1))
