Crossing continents: Oxford study reveals how pre-Columbian dogs moved slowly across the Americas, alongside farming societies

Prior to the arrival of Europeans, native dogs slowly spread southward across the Americas alongside early farming societies, mirroring the rhythms of human migration, agriculture and cultural change, a new study by the University of Oxford has shown.

All pre-(European) contact dogs in Central and South America descended from a single maternal lineage that diverged from North American dogs after humans first arrived on the continent, the study added.

An international team of scientists sequenced 70 complete mitochondrial genomes from archaeological and modern dogs, collected from Central Mexico to Central Chile and Argentina, to reach the conclusion.

A statement by Oxford quoted Aurélie Manin from the School of Archaeology as saying that “This study reinforces the important role of early agrarian societies in the spread of dogs worldwide. In the Americas, we show that their spread was slow enough to allow the dogs to structure genetically between north, central and south America. It is rather uncommon for domestic animals, and it opens new research avenues on the relationship that existed between dogs and these early agrarian societies.”

Dogs (Canis lupus familiaris) did not spread quickly across the Americas. They moved slowly, gradually adapting to new environments as they moved with people through the continents between 7,000 and 5,000 years ago, in step with the spread of maize cultivation by early farming communities, according to the study.

The Europeans, who reached the Americas with the arrival of Christopher Columbus in 1492, introduced new dog lineages that largely replaced indigenous ones.

However, interestingly, the team found that some modern Chihuahuas still carry maternal DNA from their pre-contact Mesoamerican ancestors. “These rare genetic echoes highlight an enduring legacy of the first American dogs, and the deep roots of this iconic breed,” the statement said.

The study titled Ancient dog mitogenomes support the dual dispersal of dogs and agriculture into South America is published in Proceedings of the Royal Society B.