One of the activities that geneticists pursue is the generation of genetic maps of organisms that chart the locations of the different genes on the chromosomes. Damodar Dharmanada Kosambi was not a geneticist by training and profession, but amathematician. Yet, in 1944, Kosambi wrote a classic paper about mapping function in genetics in the journal Annals of Eugenics. His lone paper in genetics was tilted ‘The estimation of map distance from recombination values’. The mapping function that Kosambi derived is still widely used by geneticists the world over for the mapping of genomes.