New research shows that domestic dogs began diversifying at least 11,000 years ago, long before modern breeding.
A major archaeological investigation has uncovered when domestic dogs first started developing the wide range of shapes and sizes familiar today.
Using advanced techniques to examine the form of hundreds of ancient dog remains collected from across tens of thousands of years, the research team tracked the early appearance of distinct dog types far back in prehistory. Their analysis identifies the point at which dogs began to branch out in body size and skull structure, placing this shift at least 11,000 years ago.
The results overturn the common belief that most canine diversity emerged only in recent centuries through selective breeding associated with the Victorian Kennel Clubs. Instead, the study shows that dogs were already displaying notable differences in skull size and shape thousands of years earlier, soon after they separated from their wolf ancestors.
Published in Science and carried out by researchers at the University of Exeter and the French CNRS, the project represents the most extensive examination of dog morphology to date, both in global coverage and historical depth. Beginning in 2014, the team studied 643 canid skulls from modern and archaeological contexts, including recognized breeds, street dogs, and wolves, covering a timespan of roughly 50,000 years.
An international group of archaeologists, curators and biologists representing more than 40 institutions worked together to produce detailed 3D models of the skulls. They examined these models with a technique called geometric morphometrics, which allowed them to study differences in size and shape with high precision.
Their findings reveal that by the Mesolithic and Neolithic periods, dogs were already showing considerable physical variety. This early range of forms likely mirrored the many roles dogs played in human communities, which included hunting, herding and providing companionship.
Dogs Diversified Early and Rapidly
“These results highlight the deep history of our relationship with dogs,” said co-lead author Dr Carly Ameen of Exeter’s Department of Archaeology and History. “Diversity among dogs isn’t just a product of Victorian breeders, but instead a legacy of thousands of years of coevolution with human societies.”
The earliest specimen identified as a domestic dog came from the Russian Mesolithic site of Veretye (dating to ~11,000 years ago). The team also identified early dogs from America (~8,500 years ago) and Asia (~7,500 years ago) with domestic skull shapes. After that, the study shows a lot of variation emerging relatively quickly.
Dr Allowen Evin, co-lead author from the CNRS based at the Institut of Evolutionary Science-Montpellier, France, explained: “A reduction in skull size for dogs is first detectable between 9,700–8,700 years ago, while an increase in size variance appears from 7,700 years ago. Greater variability in skull shape begins to emerge from around 8,200 years ago onwards.
“Modern dogs exhibit more extreme morphologies, such as short-faced bulldogs and long-faced borzois, which are absent in early archaeological specimens. However, there is a large amount of diversity among dogs even as early as the Neolithic; it was double that of Pleistocene specimens and already half the range seen in dogs today.”
The Elusive First Dogs
The study also underscores the challenges of tracing the earliest dogs. None of the Late Pleistocene specimens – some previously proposed as “proto-dogs” – had skull shapes consistent with domestication, suggesting that the very first stages of the process remain difficult to capture in the archaeological record.
Professor Greger Larson, senior author of the study from the University of Oxford, said: “The earliest phases of dog domestication are still hidden from view, and the first dogs continue to elude us. But what we can now show with confidence is that once dogs emerged, they diversified rapidly. Their early variation reflects both natural ecological pressures and the profound impact of living alongside humans.”
By demonstrating that dog diversity emerged millennia earlier than assumed, the study opens new avenues for exploring how human cultural and ecological shifts shaped the evolutionary history of our closest animal companions.
Reference: “The emergence and diversification of dog morphology” by Allowen Evin, Carly Ameen, Colline Brassard, Sophie Dennis, Ekaterina E. Antipina, Vincent Bonhomme, Myriam Boudadi-Maligne, Kate Britton, Francisco Gil Cano, Ruth F. Carden, Julien Claude, Lídia Colominas, Stefan Curth, Sergey Egorovich Fedorov, Joan Frances, Daniela C. Kalthoff, Andrew C. Kitchener, Rick Knecht, Pavel Kosintsev, Anna Linderholm, Robert Losey, Ilia Merts, Viktor Merts, Maria Mostadius, Mark Omura, Vedat Onar, Alan K. Outram, Joris Peters, André Rehazek, Erika Rosengren, Mikhail Sablin, Paul Sciulli, Maria Seguí, Z. Jack Tseng, Emma Usmanova, Victor Varfolomeev, Susan Crockford, Yaroslav Kuzmin, Laurent Frantz, Keith Dobney and Greger Larson, 13 November 2025, Science.
DOI: 10.1126/science.adt0995
The research was supported by funding from national and international agencies, including the Natural Environment Research Council (UK), the Arts and Humanities Research Council (UK), the European Research Council, the Social Sciences and Humanities Research Council of Canada, the Russian Academy of Sciences, and the Fyssen Foundation.
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