Ancient northern Eurasian hunter-gatherers may have had a role in the early domestication of wolves 14,000 to 29,000 years ago.
     During winter, when the meat of game hunted by both species was lean, prey animals would have provided more protein than humans could safely consume. Although humans may have relied on an animal-based diet during winters when plant-based foods were limited, they were probably not adapted to an entirely protein-based diet and may have favored meat rich in fat and grease. Wolves can survive on a solely protein-based diet for months, and humans may have fed excess lean meat to pet wolves during winter months, facilitating their use as hunting aids and guards, eventually leading to full domestication.
     Based on estimates of how much energy would have been left over from the meat of species that were also typical wolf prey species, such as horses, moose, and deer, study authors Maria Lahtinen of the Finnish Food Authority in Helsinki and colleagues hypothesise that if wolves and humans had hunted the same animals during harsh winters, humans would have killed wolves to reduce competition rather than domesticate them. With the exception of Mustelids such as weasels, the authors found that all prey species would have supplied more protein than humans could consume, resulting in excess that could be fed to wolves, reducing the competition for prey.
     That idea is largely based on inferences from previous research on how ancient hunter-gatherers survived in arctic environments, and new calculations suggesting that Ice Age groups could not have eaten all of the lean meat that was hunted.
     The researchers' calculations assume that, like some arctic hunter-gatherers today, ancient humans acquired 45 percent of their calories from animal protein. Humans can't eat a completely carnivorous diet because our livers can derive only part of our energy needs from protein. Ice Age hunter-gatherers probably focused on extracting fatty marrow and grease from the bones of prey to meet energy needs, leaving plenty of lean meat available as wolf food. Competition between humans and wolves for prey would have declined as generations of pet wolves gradually evolved into dogs.

Edited from PhysORG, ScienceNews (7 January 2021)