Researchers say that hunter-gatherer humans could have shared scraps with wolves in winter months, a first step toward domesticating dogs.
CNN  — 

Some dog owners like to feed their pets tidbits from the table – and this friendly habit may have had a role in the domestication of dogs at the end of the last Ice Age, scientists say.

Historically, humans and wolves were both pack hunters, and would compete for large prey, especially during leaner, winter months. But while the two species were capable of killing each other, humans instead domesticated wolves, whose descendents eventually became our dogs.

Researchers from the Finnish Food Authority, a department of the agriculture ministry, hypothesized that in feeding leftover meat to wolves, Ice Age hunter-gatherers may have had a role in the early domestication of dogs. And they say they can explain for the first time why humans would tolerate the companionship of a competitive predator during this period.

Understanding the “mutually beneficial” relationship

Modern dogs are thought to have been domesticated from wolves, but exactly when is unclear – in 2017, a study published in the journal Nature Communications found that modern dogs were domesticated from a single population of wolves 20,000 to 40,000 years ago.

Still, the team of researchers from the Finnish Food Authority wanted to know how this “mutually beneficial” relationship emerged, given that humans and wolves would have been in competition for food in the winter months.

“Humans killed cave bears and saber-toothed cats to remove other carnivores,” Maria Lahtinen, senior scientist at the Finnish Food Authority, told CNN.

“People haven’t been able to explain why humans would tolerate competitive carnivores in their living areas,” she said.

The researchers estimated how much energy would have been left over by humans from the meat of species they hunted for food, like horse, moose and deer, between 14,000 and 29,000 years ago.

Their calculations indicated that during the winter months in Europe and Asia, hunter-gatherers, who were not fully adapted to a carnivorous diet, had a surplus of lean meat, which they could have shared with wolves.

“During the late Palaeolithic period, the climate was such that most of Europe and Asia had winters,” Lahtinen, the study’s first author, told CNN. “They were cold climatic areas, which means that always, every year, (there were) conditions where humans had to access protein,” she explained.

“Humans are naturally adapted to carnivorous diets, but we can only consume approximately 20% of protein in our diet,” she said.

This excess meat could have easily been shared with wolves, the team say – a step in the direction of a mutually beneficial relationship.

“Following this initial period, incipient dogs would have become docile, being utilized in a multitude of ways such as hunting companions, beasts of burden and guards as well as going through many similar evolutionary changes as humans,” the authors wrote in the paper, published Thursday in the journal Scientific Reports.