Having previously established than humans and canines first made contact roughly 33,000 years ago—most likely in southeastern Asia—scientists are now turning their attentions towards filling in some of the details about the epic journey that turned dogs into “man’s best friend”.
In a paper published this week in the journal Cell Research, experts from the US, China, Canada, Finland, Singapore, and Sweden compared the genomes of 58 different canid species—including a dozen grey wolves, 12 indigenous dogs from northern China, 11 canines from southeast Asia, and four from Nigeria, as well as 19 selectively-bred dogs from various parts of the world.
By comparing the DNA of so many different types of canines, and determining when and where different mutations occurred, they could chart many of the connections and separations that took place throughout the ages, the Guardian and the Los Angeles Times explained on Tuesday.
What they found was that 15,000 years ago—roughly 18,000 years after a gray wolf first made contact with humans in Asia—a small pack of ancestral dogs started migrating to the Middle East, Africa, and Europe, and reached Europe about 10,000 years ago. One group also migrated to the east, breeding with endemic populations in northern China before moving on to the New World.
A more holistic approach to canine evolution
Peter Savolainen, an evolutionary geneticist at the Royal Institute of Technology in Sweden, and his colleagues sequenced the whole genomes of the 46 dog and 12 wolf species that exhibited the highest levels of genetic diversity. Their findings confirmed the date and place of origin, as dogs from East Asia shared more DNA with wolves than those anywhere else on Earth.
Furthermore, dogs from East Asia had the largest genetic diversity among the various species of canines, according to the Times. Again, this was initially discovered during an analysis of canine mitochondrial DNA, but Savolainen’s team confirmed with through their analysis of the genomic DNA, which they claim provides a more holistic approach to understanding dog evolution.
While the authors wrote that their study “for the first time, begins to reveal a large and complex landscape upon which a cascade of positive selective sweeps occurred during the domestication of dogs,” they noted that there are “many potential avenues for future research,”—such as looking at how wolves and dogs originally intermingled in the Middle East and Africa.
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