Humans and dogs walked together since Ice Age
The paper, published in Science, showed how our canine companions spread across the world with their masters, but also found intriguing periods when our shared history was decoupled.
A research team led by the Francis Crick Institute sequenced the genomes of 27 dogs, some of which lived nearly 11,000 years ago, across Europe, the Near East and Siberia.
They found that by this time, well before the domestication of any other animal, there were already at least five different types of dog with distinct genetic ancestries.
Pontus Skoglund of Crick's Ancient Genomics laboratory, the paper's senior author, said: "Some of the variation you see between dogs walking down the street today originated in the Ice Age.
"By the end of this period, dogs were already widespread across the northern hemisphere."
He added this implied that the diversity arose far earlier, "way back in time, during the hunter gatherer Stone Age, the Paleolithic, way before agriculture."
By extracting and analyzing ancient DNA from skeletal material, the researchers were able to see evolutionary changes as they occurred thousands of years ago.
The new work documents several times when human movement contributed to dog expansion. ■