Dog Domestication: Is A New Study Barking Up The Wrong Tree?

I like to believe she's thinking "What?! Dog domestication might go back 40,000 years to a single event?" — per a new Nature Communications study — but I know she's just wondering how long she has to sit still looking Mordorable before she gets another piece of cheese. (Credit William Zuback/Discover) Dogs are our first friends — they're the only animal domesticated while we were still a bunch of motley hunter-gatherers. But pinpointing the where and the when of dog domestication has been difficult. With recent advances in ancient DNA (aDNA) extraction and sequencing, it's only natural that researchers would be rushing to answer those questions. A 2016 study offered a striking new theory about dog domestication, and today a different team offers another, which they say is a direct challenge to last year's landmark paper. Do the papers really disagree or is the latest study all bark and no bite? Chew on this: Look, for a number of reasons, figuring out dog domestication is ruff. For starters, ancient wolves became our furry friends way, way before written records or even permanent human settlements that might leave behind unambiguous archaeological evidence. Sure, researchers have found a few canid remains than are more than 30,000 years old, but by appearance alone it's impossible to be certain whether these were wolves or very early dogs, in part because we know that dogs did not descend from modern wolves. They both descended from one or more lineages of ancient wolves, none of which are still around to compare and contrast. Then there's the genetic mess that researchers have to make sense of. It's about as easy as cleaning up after a puppy left alone for the day with a couch full of overstuffed throw pillows. Once domesticated, dogs still interbred with a variety of wolves, their kissing cousins, and with other populations of dogs as they traveled with their humans across continents. And that started millennia before humans were actively meddling in dogs' genomes by selectively breeding them for a variety of behavioral and physical traits, which tangled up the DNA in yet another way. Previous work in the field was also hampered by more than a little snarling, as researchers supporting different theories of dog domestication displayed terrier-like tenacity about protecting their territory. Delving Into Doggie DNA In the past few years, however, many of those same researchers have joined an international collaborative project, pooling data and resources with the goal of finally figuring out when — and where — ancient wolves became dogs. The first high profile paper from that effort, a 2016 study published in Science, proposed dog domestication occurred more than 14,000 years ago not once but twice: once in Europe and once in Asia, though the Asian population eventually migrated west and pretty much wiped out, genetically speaking, the ancient Euro-dogs. It was the first time a dual-origin theory of dog domestication had been proposed. But the arguably most exciting thing about the 2016 Science study was that it analyzed genetic data from several ancient dogs, including the complete genome of one found in Newgrange, Ireland, that was nearly 5,000 years old. It was the first time researchers were able to use such a rich body of aDNA material to investigate the backstory of dog domestication. Today, however, other researchers are declaring in Nature Communications that they "find no genetic evidence to support the recent hypothesis proposing dual origins of dog domestication." Ouch. So we've got two studies, from two highly prestigious journals, apparently facing off. Or do we? Let's look at the meat of the matter.