The Evolution of the White-Throated Sparrow

DNA sequencing took off in the early 2000s, which allowed Tuttle and Gonsor to peek at the sparrows' chromosomes. Part of chromosome two in the birds had been inverted. In most birds, the genes on chromosome two are arranged in a certain order. But with sparrow chromosome two, over a thousand genes got flipped,. This count includes the sex chromosomes; males are usually x, y, and females x, x.