A new study of hundreds of ancient and modern dog and wolf skulls finds that dogs nearly 11,000 years ago already showed about half the skull-shape diversity of modern breeds. The oldest clear domestic-dog skulls in the dataset date to roughly 11,000 years ago, consistent with DNA-based estimates for domestication. These results challenge the idea that only the last ~200 years of intensive human breeding produced most dog diversity, pointing to climate, geography and ecological roles as important drivers.
Skull Study Shows Early Dogs Had Half the Diversity of Modern Breeds — 11,000 Years Ago
A new study of hundreds of ancient and modern dog and wolf skulls finds that dogs nearly 11,000 years ago already showed about half the skull-shape diversity of modern breeds. The oldest clear domestic-dog skulls in the dataset date to roughly 11,000 years ago, consistent with DNA-based estimates for domestication. These results challenge the idea that only the last ~200 years of intensive human breeding produced most dog diversity, pointing to climate, geography and ecological roles as important drivers.
12:37 PM, 11/14/2025Science
Ancient skull analysis rewrites when dog diversity first appeared
Modern dog breeds span an astonishing range of shapes and sizes — from Chihuahua to Great Dane, corgi to greyhound, pug to German shepherd. For decades, scientists have generally attributed most of that variety to intensive human-directed breeding over roughly the past 200 years. A new study by Allowen Evin (University of Montpellier) and colleagues challenges that story.
What the researchers did
The team measured and analyzed hundreds of skulls from dogs and wolves that together span about 50,000 years. The oldest specimen in their dataset that displays clear domestic-dog characteristics dates to nearly 11,000 years ago, consistent with estimates from ancient DNA for the wolf-to-dog split.
Key findings
Contrary to prior expectations, the earliest dog specimens already show substantial variation in skull size and shape. While these ancient skulls didn’t reach the extreme anatomies seen in some modern breeds — such as the flattened face of bulldogs or the very long snout of borzois — the researchers estimate those early dogs account for roughly half the morphological diversity present in today’s dogs.
Why it matters
These results suggest that humans were not the only or even the dominant force producing early dog diversity.
Environmental factors — including climate, geographic separation, ecological roles (for example, hunting versus scavenging), and local adaptations — likely helped shape a wide range of dog forms long before the rise of intensive, breed-focused selection in the 19th century.
Broader implications and next steps
The study invites a more complex view of domestication, in which both human and natural factors interacted over millennia to produce the varied dog forms we see today. Future work combining skull morphology with ancient DNA, archaeological context, and ecological data will help clarify how different pressures influenced canine diversity in different regions and times.
Study referenced: Allowen Evin et al., analysis of modern and ancient dog and wolf skulls spanning ~50,000 years (authors’ institutional affiliations and detailed methods reported in the original publication).