Scientists have discovered evidence that dogs became human companions thousands of years earlier than previously believed, according to two studies published Wednesday in the journal Nature. The research, which analyzed ancient DNA from more than 200 dog and wolf remains, pushes back the timeline of dog domestication by at least 5,000 years.

The oldest remains examined in the studies date back approximately 15,800 years, including a jawbone found at Gough's Cave in Somerset, United Kingdom. Researchers developed new techniques to extract and analyze ancient canine DNA, which is often contaminated and difficult to study, by isolating specifically canine genetic material.

The genetic analysis revealed that dogs were already widespread across Western Europe and Asia by 14,200 years ago, during a period before the development of agriculture. These early dogs lived alongside hunter-gatherer humans who were nomadic, suggesting the human-dog relationship predated settled farming communities by thousands of years.

Interestingly, the study found that European dog populations remained genetically consistent even as human populations changed during the agricultural revolution. When new peoples migrated to Europe from southwest Asia around the dawn of farming, human genetics became more varied through intermingling, but dog genetics were less affected by these demographic shifts.

Researchers believe the first domesticated dogs likely resembled smaller wolves, though their exact appearance and roles remain unclear. Study co-author Lachie Scarsbrook from Ludwig Maximilian University of Munich noted that these ancient dogs may have served as guards or hunting companions, and likely also interacted with human children.

The findings provide new insights into one of humanity's longest relationships with another species, though scientists acknowledge more research is needed to pinpoint exactly when and where wolf domestication first occurred. The studies represent a significant advancement in understanding the deep history of the human-canine bond that continues today.