- Human hunters brought more game into their pockets than they could safely eat during the last ice age.
- Instead of wasting the excess meat, they fed it to wolves, who over time developed into tame dogs, a new study indicates.
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It is difficult to resist dogs when they beg for pieces of the table. The research to feed leftovers to hungry dogs may have started the tame housekeeping of the dogs.
A study published Thursday in the journal Scientific Reports suggests that mankind’s bond with dogs began between 14,000 and 29,000 years ago in northern Eurasia, when much of the earth was covered with ice.
Plants were scarce and prey was sparse during the harsh ice age winters. Our hunter ancestors were only able to get all 45% of the calories they need to survive by eating lean meat, as too much protein can cause poisoning (human livers are not well adapted to metabolize proteins). In the absence of vegetable carbohydrates, our ancestors relied on animal fat and fat to supplement their diet.
To get enough fat, however, hunters had to kill more lean animals such as deer and elk than they could eat in their entirety.
Therefore, hunters of the ice age fed the excess meat to wolves, according to Maria Lahtinen, lead author of the new study and an archaeologist at the Finnish Food Authority.
“The wolf and man can form a partnership without competition in the cold climate. It will easily promote domestication,” Lahtinen told Business Insider.
The offspring of the remaining wolves eventually become the first domestic dogs, her study indicates.
A male gray wolf (Canis lupus).
Dennis Fast / VWPics / Universal Images Group via Getty Images
There are many benefits to tame dogs: they can pull sleds, protect livestock or protect against other predators.
But none of these benefits became apparent long after the ancestors of the wolves were made of dogs. So scientists have long wondered about the initial reasons for dog taming.
The demand was particularly gratifying, as ancient humans and the northern wolves that occupied Eurasia tens of thousands of years ago existed on the same prey, such as caribou, rabbits, and deer. Many researchers were unlikely that the two species would willingly cooperate given the limited food resources during the ice age.
“People tend to try to eliminate other competitors,” Lahtinen said, adding.
Prior to this new study, one hypothesis was that wolves were opportunistic scavengers so attracted to the food waste that humans left behind that the two species eventually adapted to live with each other. The problem with thinking, however, was that people from the Ice Age did not settle anywhere long enough to leave consistent, removable pieces, according to Lahtinen and her co-authors.
It may therefore be more plausible that our ancestors simply caught more prey than they could safely digest, preferring to saturate their fellow predators rather than kill them.
This led to the four-legged predators staying closer and closer to humans over time until they evolved into dogs, a process that took place between 20,000 and 14,000 years ago, Lahtinen suggests.