New research proves yet again that modern horse originated in North America

/ Evolution, In The News, News
Wild horses at RTF’s San Luis Obispo, Calif., satellite sanctuary. Photo by Bari Lee.

A growing body of evidence shows that far from being an invasive species, the horse originated in North America some 53 million years ago and traveled over the Bering Land Bridge, dispersing into Asia 800,000 to 1 million years ago.

Fossil evidence had long supported the idea that horses, once leaving the Americas, evolved into a new species, and so the horses which Spanish explorers brought to the New World were unfamiliar to this land.

Advances in molecular genetics, however, have proven otherwise: the horse completed its last adaptation in North America before its absence (for what was ostensibly a short-term blip on the scale of geologic time), and so when the Spanish and then early European settlers brought horses to this new land, these horses from which today’s wild horses have descended – Equus caballus– were, in fact, returning home.

In the early 1990s work by Ann Forstén of the Department of Evolutionary Biology at Uppsala University, utilized molecular biology to more precisely describe the story of the evolution of the horse (1992). Carles Vilà, also in the Department of Evolutionary Biology at Uppsala University, verified this research in 2001. And Hofreiter et al showed that E. lambei and E. caballus were, in fact, genetically the same (2001). It was these detailed, more-accurate mitochondrial DNA assessments that showed how wild horses in American were actually a reintroduced native wildlife species.

Return to Freedom has been educating Congressional representatives, animal welfare organizations, supporters, sanctuary visitors, and government agency staff about this important research since 2005, and first spread the word about a document written by the late Drs. Jay Kirkpatrick and Pat Fazio digging into what that research meant scientifically, and in the context of wild horse management considerations.

RTF is thrilled to share a new article from Beth Shapiro and Alisa Vershinina of the UC Santa Cruz Paleogenomics Lab which provides an overview of current collaborative work among researchers, including Ross MacPhee, chair of the American Museum of Natural History’s Department of Mammalogy and an esteemed member of RTF’s science advisory committee.

Read the article here

Wild horses at RTF’s San Luis Obispo, Calif., satellite sanctuary. Photo by Bari Lee.

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