Does DNA Prove These Wild Horses Came From a Spanish Shipwreck?

A newly discovered tooth hints at how the Chincoteague ponies got to America.

Photo of ponies swimming in water
Chincoteague ponies swimming through a channel (Jim Watson / AFP / Getty)

To tell the story of how a purported cow tooth dug up in the Caribbean might corroborate the mythical origin of wild horses off the coast of Maryland and Virginia, let us begin, naturally, with a children’s book, Misty of Chincoteague.

If you know, you know—horse girls, I’m looking at you. For everyone else: This beloved 1947 children’s novel tells the story of Misty the pony, born on the beaches of an uninhabited barrier island. The story is fictional, but the setting is real. A band of wild horses still roams that island today, eating seagrass and largely ignoring tourists who come for selfies with a real-life version of Misty.

No one knows how the horses first arrived there, but Misty of Chincoteague retells a dramatic bit of local lore. It opens with literal Sturm und Drang. A Spanish galleon carrying Moorish ponies to the gold mines of Peru shipwrecks off the coast of what will later become Maryland and Virginia. The crew perishes, but the ponies swim to a nearby island and survive. “The seasons came and went,” the book goes, “and the ponies adopted the New World as their own.” In their newfound freedom, they became wild—or technically, feral, domesticated but untamed. Today, the Chincoteague Volunteer Fire Company, which manages the southern half of this horse population for historical reasons, promulgates the shipwreck origin story of the island ponies. The National Park Service, which manages the northern half, tells a decidedly less romantic tale: 17th-century settlers probably brought these horses with them.

Enter now the “cow” tooth, actually a horse tooth, mistakenly cataloged decades ago by archaeologists excavating an abandoned 16th-century Spanish settlement. And intriguingly, a recent DNA analysis suggests that the modern breed this Spanish colonial horse is most closely related to is none other than the Chincoteague pony. Given the genetic similarity, could the myth be real after all—were these mysterious ponies also Spanish colonial horses that first arrived by shipwreck?

Nicolas Delsol, now a postdoctoral researcher at the Florida Museum of Natural History, was not thinking about any of this while dealing with the troublesome “cow” tooth for his Ph.D. dissertation. He was interested in cattle domestication in the Americas, and the museum’s collections contained hundreds of cow teeth from Puerto Real, a 16th-century Spanish settlement in modern-day Haiti. Delsol picked 24 to analyze DNA from and—just his luck—one tooth had sequences that looked really, really weird. He put it aside for weeks to finish his cattle project. When he did finally return to the tooth, though, he saw that its DNA sequence was similar to that of a… the Chincoteague pony. Delsol, who is French, had never heard of it. “I was like, Wait, what are they exactly? What are these Chincoteague ponies?

Because this tooth was buried at a well-documented site in a Spanish city that existed only from 1503 to 1578, archaeologists are pretty sure the Spanish brought this horse to Puerto Real. And given its similarities in DNA, the Chincoteague pony seems likely, too, to have some Spanish ancestry. But Delsol and his co-authors are careful not to extrapolate much more. DNA alone cannot prove that horses survived a shipwreck. (Other writers have identified a 1750 Spanish shipwreck that they claim is a plausible origin event.) An alternative explanation, Delsol told me, could be that the Spanish brought horses with them while exploring the mid-Atlantic coast in the 16th century. This history is less well known than Spanish incursions farther south and west, but there are still remnants of Spanish forts in the Carolinas. Perhaps the ancestors of the Chincoteague ponies came on a journey to one of these settlements.

Wherever the first horses on the island came from, though, the horses that live there today are not exclusively descended from them. They’ve been repeatedly bred and interbred with outside horses. In the 1920s, for example, Shetland ponies were introduced to the island to add pinto coloring to the herd. And in 1975, after large numbers of horses fell ill with swamp fever, the sausage magnate Bob Evans donated mustangs to help the Chincoteague population recover. “They’re of widely mixed ancestry,” says E. Gus Cothran, an emeritus professor at Texas A&M University who studied the island population using older methods back in the 1990s. That work, he says, also “strongly supports that there is some Spanish influence.” But whether that Spanish influence came from shipwrecked horses, other horses brought by the Spanish, or residual Spanish ancestry in horses interbred with the original Chincoteague ponies is difficult to disentangle. This question is especially tricky to answer because Delsol’s analysis of the horse tooth was limited to mitochondrial DNA, which is easier to get out of degraded old samples but is passed only through the maternal line, giving an incomplete snapshot of ancestry. Plus, it’s just always hard to tell a story from only one sample, says Cristina Luis, who has studied horse genetics at the University of Lisbon.

This sample does add to a growing body of horse DNA that lays out the larger, more sweeping history of horses. The ancestors of horses today actually evolved in North America and likely crossed the Bering Strait into Eurasia, where they were first domesticated. About 10,000 years ago, however, equines went extinct in the Americas for reasons unknown. It was only after Spanish and then British, French, Dutch, and other European settlers came to the U.S. that horses once again roamed the continent. Today, American breeds are largely a mix of horses from all over—much like Americans themselves. Feral mustangs in the American West, for example, Cothran told me, were originally the descendants of Spanish horses. But as American settlers moved west, they brought with them horses that had more Northern European ancestry. Today’s mustangs are a mix of many lineages. In telling the history of horse breeds, “you are also kind of telling the history of how humans moved around the globe,” Luis told me. Indeed, however the first Chincoteague ponies arrived in America, their story is entwined with events in human history.

Still, we humans can’t help but attach more epic stories to horses. Kristen Guest, an English professor at the University of Northern British Columbia who is studying the history of horse breeds, says she’s come across a shipwreck origin story multiple times in her research. One of the ancestors of Clydesdales, for example, was purportedly an Arabian horse that was shipwrecked and swam to Scotland. “I don’t think it’s accidental that you keep getting the same versions of the story all over the place,” she told me. “There’s something about the idea that these ordinary little horses have this romantic history.” We romanticize our own past too. “Human beings, when they imagine their genetic history—nobody imagines their ancestors dug ditches,” Guest said. We’d rather imagine ourselves as descendants of Charlemagne.

For Delsol, this has all been a rather fascinating detour through the history of horses. He’s still trying to get the cattle research from his Ph.D. work published. But, he admitted, “I don’t know if it’s going to draw as much attention as Chincoteague ponies.”