Origin of the Horse

Descended from the mounts of the Conquistadors, shaped by a vanishing frontier, wild horses have been renegades for centuries, becoming romantic symbols of freedom. History and literature alike are rife with tales of uncommon bonds between heroes and the wild horses they tamed to ride into battle. Young girls fantasize about a knight in shining armor atop a valiant white steed who gallops in to sweep them off their feet. Young boys envision taming wild stallions and riding into town, like a howling desert wind to rout out an infestation of bad guys. Even the various mounts of Jedi Knights seem suspiciously equine.

Evolution of The Horse

The very first horses evolved on the North American continent over 55 million years ago. Over millions of years they roamed the grasslands slowly extending their range to most of the continents on earth. Then horses migrated across the Bering land bridge from North America into what is now Siberia. From there, they spread across Asia into Europe and south to the Middle East and Northern Africa.

"Then, about 8,000 B.C. — succumbing to climate change and human hunters — the horses vanished from North America completely."

Our understanding of the evolution of the horse has evolved as well. Paleontologist Kathleen Hunt has done a good job of outlining this evolution on her "Talks Origin" site. In the 1870's, the paleontologist O.C. Marsh published a description of newly discovered North American horse fossils. At the time, very few transitional fossils were known. The sequence of horse fossils that Marsh described (and that T.H. Huxley popularized) was a striking example of evolution taking place in a single lineage. Here, through a series of clear intermediates, one could see the fossil species Eohippus transforming into an almost totally different-looking (and very familiar) descendent, Equus. Biologists and interested laypeople alike were justifiably excited.