Here’s a very interesting survey article from the Ensia site on the issue of species hybridization . . .
Native wolves had been eradicated and the forests of the eastern United States long cut down when residents of western New York first began to notice the arrival of coyotes in the 1940s.
The coyotes of the Rocky Mountains and Great Plains were lithe and quick, usually weighing less than 30 pounds. The newcomers were different…
Indeed, scientists have since discovered these super-sized coyotes are only about two-thirds coyote. About 10 percent of their genes belong to domestic dogs and a quarter comes from wolves, with which they hybridized as they moved east north of the Great Lakes . . .