The history of the dog on the American continent began in the upper latitudes some 15,000 years before our era. Canis familiaris accompanied the early waves of humans who ventured into North America. “The first canids arrived via the Arctic, from Siberia. Those dogs – possibly used to pull sleds – no doubt crossed the Beringia region, where the Bering Strait is today, to reach what is now Alaska,” recounts Aurélie Manin, an archaeozoologist at the ArchAm joint research unit1.

Canids soon made their place in North America: “We have found dog skeletons there dating back 8,000 to 9,000 years, which shows that their dispersal occurred quite early in that part of the continent,” the researcher adds. “They accompanied the first North American populations of hunter-gatherers.” In contrast, the archaeological evidence points to a much later dispersal in Central and South America, dating from 5,500 years ago.

Mitochondrial DNA holds the key

What is the reason for this discrepancy? In an attempt to unravel this peculiar mystery, an international research team involving several CNRS laboratories2, including Manin’s, analysed DNA from the skeletal remains of 123 dogs dating from the past 2,000 years and spanning a vast area from central Mexico to northern Patagonia. The DNA sequences of 12 modern-day dogs were also examined.

An aerial view of the burial area at Huaca Amarilla, an archaeological site on the Pacific coast of far northern Peru that has yielded dog bones.

An aerial view of the burial area at Huaca Amarilla, an archaeological site on the Pacific coast of far northern Peru that has yielded dog bones.

Nicolas Goepfert / ARCHAM / CNRS Images

Nicolas Goepfert / ARCHAM / CNRS Images

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For the study, which was published on 18 June, 2025 in the journal Proceedings of the Royal Society B: Biological Sciences3, Manin and her team decided to focus on the DNA found in mitochondria rather than that contained in cellular nuclei. “Unlike DNA from the Arctic zones, which is quite well preserved, rather like in a freezer, the genetic material of bones found in tropical or temperate environments is often degraded,” the researcher explains. “The advantage of DNA from mitochondria is that each cell has a great many of these organelles, thus increasing the likelihood of being able to extract this DNA from our archaeological samples.”

Mitochondrial DNA has another advantageous feature: it is transmitted by the mother only, which makes it possible to trace precise maternal evolutionary lineages. “Once the DNA was extracted and sequenced, we obtained enough information to formulate evolutionary models and thus understand how each individual was related to the others,” Manin says. In this way, the researchers pieced together part of the history of the dog’s dispersal across the continent.

The dog’s role in sedentarisation

“Our findings show that dogs arrived in Central and South America between 7,000 and 5,000 years ago, at a time when hunter-fisher-gatherer societies were transitioning to more sedentary ways of life based on the development of agriculture,” Manin explains. Unlike the hunter-gatherers of North America (who used canids in hunting and conferred them a symbolic role, including them in mortuary rituals), the groups who populated the southern continent beginning ca. 14,000 BC did not bring dogs with them.

So how did these animals come to coexist, thousands of years later, with the earliest South American farmers? “They could have been brought in on purpose by the people, who may have used them to guard their villages, for example,” Manin hypothesises. “But it’s also possible that they simply took advantage of the surplus food generated by agricultural activity. They might have been found prowling around the villages, feeding on the waste left behind by humans.”

The last of the indigenous dogs

The genetic analyses conducted by Manin and her team further reveal an abrupt turning point in the history of the dispersal of dogs in America. The arrival of European settlers, from 1492 onwards, marked the decline and eventually the near-complete extinction of the native dogs’ maternal lineages. “We observed a replacement of pre-contact canid lineages by European dogs,” the researcher reports, “and the data suggests that this change came about rather quickly.” The only notable exception is that certain modern-day Chihuahuas have retained traces of their pre-contact Mesoamerican origins.

A canine skull is unearthed at the Huaca Grande archaeological site in Peru.

A canine skull is unearthed at the Huaca Grande archaeological site in Peru.

Cyril Frésillon / ARCHAM / CNRS Images

Cyril Frésillon / ARCHAM / CNRS Images

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What is the explanation for such large-scale replacement? According to Manin, “The indigenous populations may have been banned from keeping dogs from the ancient lineages, similar to the bans imposed by the colonisers on various forms of breeding camelids and guinea pigs.”

Another hypothesis is that certain European dogs specially trained for attacking and fighting could have decimated some populations of canids from pre-contact lineages. “Or perhaps the European canids were better adapted to the cities being built by the settlers,” Manin suggests.

Protected from European influence?

The mystery has yet to be solved – just like that of the Chihuahua, the surprising sole heir of the indigenous lineages. “The breed originated in the Chihuahua region of Mexico, a zone that is partly covered by a desert, little urbanised and sparsely populated. It did not hold a particular attraction for the colonial powers, which allowed indigenous practices to endure longer in that area,” Manin explains.

Was this tiny dog thus protected against European influence? According to the researcher, “It could also have been a desire on the part of the Europeans to preserve the aesthetic characteristics of a breed that had especially drawn their attention, as evidenced by a number of written records from the 19th century.” Nonetheless, as Manin notes, the presence of ancient DNA in the Chihuahua could be purely the result of chance. One thing is certain: the dogs of the Americas are far from having divulged all of their secrets.

For further reading

Rethinking the Origin of Dogs
How Cats Conquered the World
Animals: from mechanical objects to sentient subjects
Amazing animal cultures