A map of the yellow (y), white (w), and
miniature (m) genes on the X chromosome of Drosophila melanogaster.
Each number represents the percentage of recombinant offspring produced between two loci and is defined as the
1% recombination between two genes on a chromosome is defined as 1 map unit (mu),
or 1 centimorgan (cM).
The interloci distances are additive.