While the evidence isn't conclusive, Axelsson noted that the genetic data combined with the researchers' collective understanding of archeology and other fields fits their conclusion: dogs' increased ability to thrive on starchy food, as opposed to the meat-rich diets of wolves, represents an important step in domestication. The research was published in the Jan. 23 issue of the journal Nature.
To understand the genetic changes associated with the transition from wolves to dogs, the researchers compared whole-genome sequences of domesticated dogs with those of wolves. Genomes are a full set of chromosomes representing all the inheritable traits of a single organism.
From 3.8 million genetic variants, the researchers identified 36 targeted genetic regions that likely played a role in the domestication of dogs. Eight of these regions had genes related to nervous system pathways and 10 had genes involved in starch digestion.
Axelsson explained how the researchers know when they've identified something critical through the genetic analysis: "When a mutation occurs, it will arise in one individual and if the mutation confers a good trait -- in this case being able to digest starch -- then in a relatively short time period, everyone will carry that mutation. Usually there are lots of other mutations, too, but nearby that mutation for the good trait, there won't be any other mutations or genetic variations in that region."
So, "When all dogs look similar on the genetic level, then you have a signal, or a sign, that selection is happening," Axelsson said.
The researchers said that the study results show how coping with an increasingly starch-rich diet when humans began to grow their own food caused similar adaptive responses in dog and human.
While this may all sound quite academic, Dr. Amber Andersen, a veterinarian at Point Vicente Animal Hospital in Palos Verdes, Calif., said the
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