A success story: this is how the partnership between humans and dogs can be described, sealed during the last Ice Age, when wild wolves were domesticated. Two recently published articles help to understand how the collaboration between the two species helped both to evolve and spread across the planet.
In a study published in Scientific Reports, researchers from the Finnish Food Authority, an organ of the Finnish Ministry of Agriculture, found that the domestication of dogs was not due to the choice of cute puppies of wolves adopted by humans as companions. The real reason would be man’s limited ability to digest proteins, which is not a problem for wolves or dogs.
The most likely reason for the partnership, according to chemist and archaeologist Maria Lahtinen, the study’s lead author, was the abundance of proteins that human populations, through hunting, were able to accumulate to keep both species fed in the harsh winter months. This led to a decrease in competition between them.
The study was based on models to calculate how much energy captured prey (deer, elk and horse) would provide: all animals consumed by humans would have provided more protein than necessary for their survival – if men and wolves had fought for these resources, cooperation between the two species would never have arisen.
Together in the New World
And together, according to a study by researchers at the University of Buffalo (USA), they spread across the world. A fragment of dog bone about 10,150 years old, found on the shores of the Gulf of Alaska, may indicate the route that the first humans used to migrate from Eurasia to the American continent. According to the researchers, the remains of the fossilized femur are the oldest records of a domestic dog in the Americas.
The mitochondrial genome, passed from mother to son, revealed that it belonged to a lineage that separated from Siberian dogs 16.7 thousand years ago, sharing a common ancestor with dogs that lived on American soil before the arrival of European colonists.
“The timing of this division coincides with a period when humans appear to have migrated to North America along a coastal route that included southeastern Alaska. Now, we have genetic evidence: our data helps to provide not only a moment, but also a place for dogs and people to enter the Americas, when coastal glaciers retreated during the last Ice Age, “said evolutionary biologist Charlotte Lindqvist, main author of the study.