New research led by the University of Helsinki suggests that dog domestication needs to be understood in terms of competition over resources in the particularly severe environment that prevailed in northern Eurasia during the latter part of the Last Ice Age (29,000 to 14,000 years ago).
“Humans are not fully adapted to a carnivorous diet. Human consumption of meat is limited by the liver’s capacity to metabolize protein,” said Dr. Maria Lahtinen from the Finnish Museum of Natural History at the University of Helsinki and the Finnish Food Authority and hert colleagues.
“Contrary to humans, wolves can thrive on lean meat for months.”
“We suggest that the differences between dietary constraints of wolves and humans enabled dog domestication in harsh environments in the Late Pleistocene.”
In the study, the researchers used energy content calculations to estimate how much energy would have been left over by humans from the meat of species (horses, moose and deer) they may have hunted 14,000 to 29,000 years that were also typical wolf prey species.
They hypothesized 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 weasel-like animals, the scientists found that all prey species would have supplied more protein than humans could consume, resulting in excess lean meat that could be fed to wolves, thus reducing the competition for prey.
“Our calculations show that during harsh winters, when game is lean and devoid of fat, Late Pleistocene hunters-gatherers in Eurasia would have a surplus of animal derived protein that could have been shared with incipient dogs,” they said.
“Our partitioning theory explains how competition may have been ameliorated during the initial phase of dog domestication.”
“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 research is described in a paper in the journal Scientific Reports.
M. Lahtinen et al. 2021. Excess protein enabled dog domestication during severe Ice Age winters. Sci Rep 11, 7; doi: 10.1038/s41598-020-78214-4