But this isn't a final answer. It's just the latest volley in a long-running debate about when, where, and why wild wolves first transformed into man's best friend. “It almost completes the set of possible areas where dogs may have been domesticated,” says Greger Larson from the University of Oxford in an email statement. “Previous genetic analyses have pointed a finger at, or at least gestured in the direction of, Europe, the Near East, Siberia, and China. Adding Central Asia now means that everyone with a favourite region can point to at least one paper that supports their suspicions.”
The oldest dog fossils are at least 15,000 years old and come from Western Europe and Siberia. But genetic studies have thrown forth hugely conflicting answers depending on whether they look at modern DNA from living dogs or ancient DNA from fossil ones, which parts of the world they collect samples from, and whether they look at full genomes, specific markers, just the Y chromosome, or just mitochondrial DNA (a secondary genome that sits outside the main one).
In 2013 alone, a whole-genome study of living wolves and dogs argued that domestication took place around 10,000 years ago during the Agricultural Revolution, when wolves that scavenged at humanity's scrapheap became more accustomed to life with us. Four months later, another whole-genome study argued that wolves were domesticated in East Asia around 32,000 years ago. Six months after that, yet another study—this one of mitochondrial DNA in both modern and fossil dogs—put the site of domestication in Europe and the time somewhere between 18,000 and 32,000 years ago. That's well before the Agricultural Revolution, and suggests that wolves may have accompanied European hunter-gatherers as either hunting partners or scavengers.
Boyko's study doesn't resolve this morass of conflicting results, but it does adds two valuable new things. First, the team focused on village dogs, which have been largely ignored till now. Second, they used a different method than previous genetic studies. They relied on a well-known phenomenon called linkage disequilibrium (LD), in which nearby genes, which are normally inherited as a single chunk, are more likely to break apart over time.
If you look at human populations, you see the least amount of LD in east Africa and increasing amounts in more distant parts of the globe—this reflects the African origin of our species, and our subsequent planetary expansion. Similarly, Boyko's team found the least amount of LD among village dogs in Central Asia, pinpointing this region as the cradle of domestication.
But Olaf Thalmann from the University of Oulu says that LD is a rather “crude estimator.” There are other explanations for the pattern that the team saw. For example, domestic dogs could have evolved in the Middle East or Europe and been carried to Central Asia by humans, before going extinct in their site of origin. “Will this be the last word in dog domestication?” asks Thalmann. “I highly doubt it. I personally think that we reached a dead end with inferences from modern data.”