“The tightness of genetic linkage, in short, was a surrogate for the physical proximity of genes on chromosomes: by measuring how often two features-blond-hairedness and blue-eyedness-were linked or unlinked, you could measure the distance between their genes on the chromosome.” — Siddhartha Mukherjee Copy Share Image
“The gene responsible for creating white eyes (called white eyed), for instance, was inescapably linked to maleness: no matter how Morgan crossed his flies, only males were born with white eyes. Similarly, the gene for sable color was linked with… — Siddhartha Mukherjee Copy Share Image
