Date: August 24, 2018 10:29AM
Should the wild horses that roam North America be considered native wildlife? They may have been “introduced” by man, but scientific evidence suggests that they are genetically the same as the horses that became extinct on the continent between 11,000 and 13,000 years. In fact, the genus Equus could have been wiped out entirely had it not crossed the Bering Stait land bridge into Eurasia. Jay F. Kirkpatrick, Ph.D. and Patricia M. Fazio, Ph.D. look at the evidence.
Are wild horses truly “wild,” as an indigenous species in North America, or are they “feral” weeds – barnyard escapees, far removed genetically from their prehistoric ancestors? The question at hand is, therefore, whether or not modern horses, Equus caballus, should be considered native wildlife.
The genus Equus, which includes modern horses, zebras, and asses, is the only surviving genus in a once diverse family of horses that included 27 genera. The precise date of origin for the genus Equus is unknown, but evidence documents the dispersal of Equus from North America to Eurasia approximately 2 to 3 million years ago and a possible origin at about 3.4 to 3.9 million years ago. Following this original emigration, several extinctions occurred in North America, with additional migrations to Asia (presumably across the Bering Land Bridge), and return migrations back to North America, over time. The last North American extinction occurred between 13,000 and 11,000 years ago.