New research indicates that the significant physical diversity observed in domestic dogs emerged earlier than commonly believed. While selective breeding during the Victorian era, approximately 200 years ago, is often cited as the primary origin of this diversity, recent analyses suggest a much older timeline.
Early Canine Diversity
A study led by Carly Ameen, a bioarchaeologist at the University of Exeter, analyzed hundreds of prehistoric canine skulls spanning the last 50,000 years. The research involved creating 3D models of 643 skulls from ancient and modern dogs and wolves to detect subtle changes in their shape over time.
The findings, published in the journal Science, show that by approximately 10,000 years ago, nearly half of the diversity present in modern dogs was already established. By 11,000 years ago, shortly after the last ice age, dog skulls were distinctly different from those of wolves, exhibiting shorter and wider forms. Furthermore, dog skulls from this period already displayed variations among themselves, indicating that the transition from wolf to dog had occurred considerably earlier. These changes are understood to accumulate gradually over multiple generations, not instantaneously.
Implications for Domestication
This research suggests that the domestication of dogs, believed to be the first domesticated species (pre-dating livestock and crops), has a longer history than previously assumed. While the study does not pinpoint the exact start date of dog domestication, it narrows the potential timeframe and offers insights into the physical evolution of dogs through their relationship with humans.
Ancient Human-Dog Relationship
Another study, also published in Science, utilized ancient dog DNA to investigate the human-dog relationship across Eurasia over the past 10,000 years. Led by Minmin Ma, a researcher at Lanzhou University in China, this study determined that humans transported and potentially traded domestic dogs during migrations.
- Prehistoric hunter-gatherer societies likely integrated dogs into their migrations due to their utility in hunting.
- Even prehistoric farming and pastoral societies, despite dogs being less essential for their economic activities involving cattle, sheep, and horses, consistently brought dogs with them during movements.
These studies collectively highlight that dogs have maintained a close companionship with humans across diverse periods and cultures, even as their roles have evolved.