A horse tooth discovered on the island of Haiti comes from one of the oldest known domestic horses in the western hemisphere. DNA analyzes show that this horse must have been brought to the Caribbean from Spain by the conquistadors as early as the 16th century. The DNA sample also confirms a legend according to which wild ponies on the island of Chincoteague off the coast of Virginia are said to have descended from a Spanish galleon that sunk there: These wild ponies are the closest modern relatives of the conquistador horse.
All of the horses living in North America today were imported by early settlers from Europe—that much is clear. All of the original wild horses native to this continent died out at the end of the last ice age. “It was not until the late 15th century, with the arrival of the first European explorers in the Caribbean, that horses also returned to America – this time in the form of the domesticated horse Equus caballus,” explain Nicolas Delsol of the University of Florida at Gainesville and his colleagues.
Columbus brought the first horses with him
Historical records suggest that the first European horses arrived in the Caribbean as early as Christopher Columbus’ second voyage. “According to reports from Oviedo y Valdés, Columbus took these horses on board in the Canary Islands. Then, on November 28, 1493, they landed in the town of La Isabela on the island of Hispaniola,” said Delsol and his team. Over the next few decades, more and more horses came to the island with the ships of the conquistadors and were also brought to the Central American mainland.
“One of the most iconic episodes of this era is the arrival of Hernan Cortés’ 16 horses on Mexico’s Gulf Coast,” the researchers report. “These animals were so essential for the success of the Spanish conquerors that the Spanish historian Bernal Diaz del Castillo gave each of these horses a detailed description and their names.” According to the common assumption, the imported horses continued to multiply and form together with others from later generations horses brought by European settlers formed the basis of all modern-day North American horses, including the mustangs.
A horse tooth from Puerto Real
The problem, however, is that even if historical records suggest this process, there are hardly any archaeological finds of the horses imported by the Spaniards. Only one study has isolated the DNA of a 17th-century Native American horse, but little has been revealed about its ancestry. At this point, a chance discovery comes into play that Delsol made during the genetic analysis of cattle teeth from the approximately 400-year-old Puerto Real settlement in northern Haiti. This place was founded by the conquistadors in 1503 and was one of the most important ports of call for ships from Spain in the Caribbean. However, in 1578 Puerto Real was abandoned and later destroyed.
“I was sequencing the mitochondrial DNA of the fossil teeth when I noticed that one of the teeth didn’t match,” says Delsol. As it turned out, it wasn’t a cow’s tooth, but a horse’s tooth. “This gave us the unique opportunity to clarify the question of the origin of the first colonial horses and their relationship to European horse breeds of the time,” the researchers explain. “The connection between these conquistador horses and modern wild horses in North America can also be examined.” To do this, the scientists compared the mitochondrial DNA – which reveals the maternal lineage of the horse – with that of 83 genomes of modern and historical horses.
Chincoteague pony mystery solved?
The analyzes revealed that the horse from Puerto Real belonged to haplotype A, a lineage group formerly found primarily in horses in Central Asia, southern Europe and the Middle East. In contrast, horse breeds with this gene type were not widespread in northern and central Europe at the time of the conquistadors. “However, horses of this haplotype are known from archaeological sites of the Bronze Age on the Iberian Peninsula,” the scientists report. In their view, this suggests that the first horses brought to North America actually came from Spain and, as reported by historical sources, were brought to the Caribbean via the Canary Islands.
Interesting, however: The closest relatives of the Puerto Real horse today do not live in Spain, but on the island of Chincoteague off the coast of the US state of Virginia – around 1500 kilometers north of Haiti. The Chincoteague ponies have lived on this barrier island for several hundred years. So far, however, it has been disputed whether they come from the first English settlers in this area or from the conquistadors. According to legend, the horses are said to have escaped from a Spanish galleon that ran aground and sank off the island. The DNA comparisons now show that this story could be true. “It’s not well documented, but the Spanish explored this area early in the 16th century,” explains Delsol. The close relationship between the horse from Puerto Real and the Chincoteague ponies could now confirm this.
Source: Florida Museum of Natural History; Specialist article: PLoS ONE, doi: 10.1371/journal.pone.0270600