Ancient skulls and DNA reveal deep roots of dog diversity and human migrations across Eurasia

The Conversation reports on two Science studies led by Allowen Evin of the University of Montpellier and Shao-Jie Zhang of the Kunming Institute of Zoology. An analysis of 643 Late Pleistocene to Holocene dog and wolf skulls suggests the distinctive dog-like skull shape emerged around 11,000 years ago, with substantial skull diversity even before modern breeding intensification. A parallel study of 73 ancient dog genomes over the last 10,000 years shows dogs shifting their ancestry in Eastern Eurasia in step with human movements, from hunter-gatherers to farmers and pastoralists. Together, these findings indicate that dog diversity has deep roots and that dogs traveled with humans, acting as living records of ancient cultural exchange. This piece is based on The Conversation’s coverage of Science articles and the original publisher is The Conversation.

Overview

Two Science studies, one led by Allowen Evin and another by Shao-Jie Zhang, illuminate the deep origins of dog diversity and how dogs tracked human movements across Eurasia over more than 10,000 years. The work challenges the view that modern dog variation is primarily a product of recent, intense breeding, showing that morphological and genetic diversity predates much of today’s selective breeding.

“The dog-like skull shape first arose around 11,000 years ago, marking a turning point in dog diversification,” - Allowen Evin, University of Montpellier.

Origins of modern dog diversity: morphology through time

Evin and colleagues analyzed 643 dog and wolf skulls spanning the Late Pleistocene to the Holocene (129,000 to 11,700 years ago), including some skulls 50,000 years old. Their 3D photogrammetry and morphological reconstructions indicate that the hallmark “dog-like” skull configuration appears around 11,000 years ago, with substantial skull-shape diversity present among Holocene dogs. Importantly, the late Pleistocene skulls were wolf-like, suggesting that a wolf-dog divergence occurred earlier, but the distinctive canine cranial morphology did not begin to diversify until the Holocene. Some Holocene skulls retained wolf-like features, underscoring a gradual transition and a broader spectrum of early canine forms than previously recognized.

“The genetic and morphological foundations for today’s dog diversity were laid thousands of years ago,” - Allowen Evin.

Moving together: dog lineages and ancient human journeys

A separate study by Zhang and colleagues examined 73 ancient dog genomes from the last 10,000 years to trace how dogs moved across Eastern Eurasia in tandem with humans. The results show multiple shifts in dog ancestry that align with the migrations of Neolithic hunter-gatherers, farmers, and pastoralists, suggesting dogs often accompanied migrating human groups and carried their distinctive genetic signatures. In some cases, human and dog population histories diverged, highlighting complex dynamics in dog evolution and human culture across Asia.

“Dogs moved as biocultural packages that accompanied humans across Eastern Eurasia,” - Shao-Jie Zhang, Kunming Institute of Zoology.

Implications for the dog-human relationship

These findings imply that the extraordinary variety seen in modern dogs did not emerge solely from late centuries of selective breeding. Natural selection, human choice, and environmental diversity over millennia laid the groundwork for the size, shape, and genetic diversity observed today. The research also positions ancient dogs as living records of ancient human migrations and cultural exchanges, suggesting that canine diversity accompanied, mirrored, and sometimes facilitated human movement and interaction across Eurasia.

Together, the skull morphology work and ancient DNA analysis reshape our understanding of domestication, indicating a far older and more geographically widespread process than previously appreciated. The studies emphasize a nuanced, long-term interplay between humans and dogs as partners in exploration, trade, and daily life over more than 10,000 years.

Reshaping our understanding of dogs

Ultimately, these studies argue that the groundwork for dog diversity was laid long before the modern era of selective breeding. They invite further research into the physical diversity and ancestry of dogs through time, potentially revealing additional complexities in how dogs evolved in concert with human societies across the globe. The relationship between humans and dogs emerges as a shared, millennial narrative, rich with evidence of co-migration, cultural exchange, and adaptation across varied environments.

This summary draws on The Conversation's coverage of two Science studies, highlighting the collaborative efforts of researchers across institutions to illuminate the deep, intertwined history of dogs and humans.