Paleolithic hunters and wolves formed a cooperative alliance to change evolution

Paleolithic hunters and wolves established a cooperative relationship that shaped the evolution of both species over thousands of years.

Researchers suggest that the domestication of dogs began when less fearful wolves approached human camps to scavenge for food. These tolerant wolves survived more often than aggressive ones, allowing traits for docility to spread through the population via natural selection. Humans then reinforced this proximity by raising wolf pups, which socialized the animals to human voices and movements.

While raising a single wolf did not change its instincts, breeding generations of tolerant individuals eventually modified the population's hereditary traits. Anthropologist Pat Shipman says these early canines helped humans by chasing large prey like bison and elk until the animals were exhausted. Humans would then finish the hunt with weapons while the canines stayed away from the most dangerous moments. In exchange, the humans shared meat with the animals.

This cooperation also provided protection against other predators that might steal kills. Shipman notes that the white sclera, the white part of the eye, in both humans and wolves might have helped them coordinate movements silently during these hunts. The impact of this alliance may have influenced the disappearance of Neanderthals. Shipman proposes that the humans' ability to hunt more effectively with canine partners gave them a competitive advantage over Neanderthals who lacked such allies.

Skeletal remains from sites in Belgium and the Czech Republic show physical changes in these ancient canines, such as shorter snouts and wider jaws. Isotopic analysis of these bones also indicates that these animals ate diets similar to humans, further proving their close association.