Women in a forested area 8,000 years ago were not only in close contact with dogs, but they were also eating the same food the dogs ate and suffering from one or more illnesses the dogs had.
A new study published in the Journal of Archaeological Science reveals that dogs weren't just prehistoric man's best friend. At least some women during the Early Neolithic period, and likely their children too, also lived very canine-centric lives.
"It is possible that females were more involved in caring for the dogs -- possibly more often the ones who fed them, organized living quarters for them, and cleaned up after them," lead author Andrea Waters-Rist told Discovery News.
Waters-Rist, a Leiden University archaeologist, added: "One can envision a camp in the boreal forest with people and dogs living side by side, and dogs being used in many everyday tasks, with dogs being as important to the group as they are to many people today."
Waters-Rist and her team analyzed remains from two 8,000-year-old cemeteries near Lake Baikal, Siberia. The researchers determined that women from both cemeteries had, at some point in their lives, suffered from a parasitic infection called hydatid disease, or echinococcosis.
"It's been recognized for centuries -- mentioned in ancient Greco-Roman and Jewish texts -- and in modern times it is a relatively common infection in Northern Eurasian reindeer herders who use dogs to help with herding, and in indigenous Alaskan groups reliant on sled dogs," Waters-Rist explained.
Cysts from the parasites, which look like calcified, egg-like objects, were found in the abdomens of the women. The researchers suspect that the cysts were probably growing in the liver of each person.
Echinococcosis in humans almost always occurs as a result of direct contact with dogs. People can also get it after ingesting food or water that has been contaminated by dog feces that contain the parasitic eggs.
"As these cysts take many years to form and may not have always preserved," Waters-Rist said, "it suggests that many more people were likely infected. So it is a piece of the puzzle in our reconstruction of the importance of dogs in the lives of ancient peoples."
Robert Losey, a University of Alberta anthropologist, told Discovery News that he previously documented "intentional burial of dogs and wolves" at the same Siberian cemeteries.
"These dogs were much like modern Siberian huskies," Losey said. "Upon their deaths, they were carefully placed in graves just like the human dead."
Some dogs in the Siberian cemeteries were buried with implements such as spoons and stone knives. One dog was even interred wearing a necklace.
The people living at the site appear to have been hunter-gatherers who fished for both their own supper and that of their dogs. The scientists know the dogs and people were eating similar diets based on chemical analysis of their bones.
Dogs and humans at other locations worldwide could have been equally close during prehistoric times, but proof of such connections can be harder to find where populations were low. Losey explained that dog burials tend to be more common finds in areas where diets were rich in aquatic foods, because such spots generally had denser human populations.
The Siberian dog burials strongly suggest that the canines were valued for more than just their hunting, guarding, and other probable work efforts.
"Altogether, several lines of evidence -- the intentional burial of dogs in cemeteries, their similar diets, and now a shared disease -- demonstrate that these ancient Siberian foragers likely had close physical and emotional ties with their domesticated dogs," Waters-Rist said.