Wild horses originated in N. America

LINDELL BEACH, B.C. – New research suggests that wild horses in North America should be considered a native species, rather than domesticated animals turned feral.

Jay Kirkpatrick, director of the Science and Conservation Center in Billings, Montana, in a paper co-authored with Patricia Fazio, argues that the question is important because management approaches might change if feral horses were recognized as native wildlife.

“The question is legitimate and the answer important,” he wrote.

“In North America, the wild horse is often labelled as a non-native or even an exotic species by most federal or state agencies dealing with wildlife management.”

Critics have argued that the Spanish horse was a different species from the one that disappeared 11,000 years ago, but they hadn’t counted on the new field of molecular biology.

The scientific name for the modern domestic horse is Equus caballus. According to fossil records found in the Alaskan and Yukon permafrost, Equus lambei was the last wild horse to go extinct.

Researchers, using mitochondrial DNA analysis and examining the genetics of the fossil remains, found that the variation was within that of the modern horse.


E. lambei and E. caballus are genetically the same animal.

Equus caballus has a rich, ancestral history.

Kirkpatrick wrote that work by Swedish researchers has set the date of origin for E. caballus at about 1.7 million years ago in North America.

“No evidence exists for the origin of E. caballus anywhere except North America.”

Following the horse’s ancestral history, a team of British and German researchers looked at whether today’s domestic horse is the descendent of one or more post-glacial primitive horses.

They took mtDNA samples from 318 horses in 25 oriental and European breeds, North American wild horses and the Przewalski’s horse, an endangered breed also know as the Asian or Mongolian wild horse. They also used published data on prehistoric permafrost horses.

In total, they collected genetic information on 652 horses and confirmed that today’s horses are descended from the post-glacial ancient horses.


Kirkpatrick said the molecular biology evidence is indisputable.

The fact that Spanish horses were domesticated before they were reintroduced matters little from a biological viewpoint, he added.

They are the same species that originated in North America and whether they were domesticated is irrelevant.

He said domestication altered little of the animals’ biology, which is reinforced by the phenomenon called “going wild,” where horses let loose revert to ancient behavioural patterns, an instinct scientifically referred to as “social conservation.”

There are two key elements that describe an animal as a native species: where it originated and whether it co-evolved with its habitat.

Kirkpatrick said there is no doubt E caballus did both in North America.