Before we began adopting dogs to keep us company, our ancestors bred them for a very different reason: work. Today, researchers published the largest evolutionary tree of dogs to date, which reveals how various types of dogs were bred for specific tasks, like keeping predators at bay or herding livestock.
In order to construct the evolutionary tree, published in the journal Cell Reports, the researchers sequenced the genes of 161 breeds.
“What we [found] is four different groups of herders that developed in different parts of the world at different points in time,” said Elaine Ostrander of the Cancer Genetics and Comparative Genomics Branch at the National Human Genome Research Institute.
“It makes sense,” she added, “because the dogs that you would need to drive bison on the plains have to have a different set of skills than those who herd goats on rocky territory, which is going to be different than what you use to move sheep in a pastoral setting.”
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The findings are significant because they provide a complete framework for mapping breed behavior, something that Ostrander is often asked about in her line of work.
“The question I get asked most often is ‘when are you going to map genes for breed behavior?’” Ostrander said. “[But] no one has really had any luck doing that and partly it’s because we’ve grouped everything together and now we know that’s not the right way to go. We need to consider these herders separately because their underlying genetics are going to be different.”