Over 20,000 years ago, humans won the evolutionary battle against Neanderthals. They may have had some assistance in that from their best friends.
One of the most compelling -- and enduring -- mysteries in archaeology concerns the rise of early humans and the decline of Neanderthals. For about 250,000 years, Neanderthals lived and evolved, quite successfully, in the area that is now Europe. Somewhere between 45,000 and 35,000 years ago, early humans came along.
They proliferated in their new environment, their population increasing tenfold in the 10,000 years after they arrived; Neanderthals declined and finally died away.
What happened? What went so wrong for the Neanderthals -- and what went so right for us humans?
The cause, some theories go, may have been environmental, with Neanderthals' decline a byproduct of -- yikes -- climate change. It may have been social as humans developed the ability to cooperate and avail themselves of the evolutionary benefits of social cohesion. It may have been technological, with humans simply developing more advanced tools and hunting weapons that allowed them to snare food while their less-skilled counterparts starved away.
The Cambridge researchers Paul Mellars and Jennifer French have another theory, though. In a paper in the journal Science, they concluded that "numerical supremacy alone may have been a critical factor" in human dominance -- with humans simply crowding out the Neanderthals. Now, with an analysis in American Scientist, the anthropologist Pat Shipman is building on their work. After analyzing the Mellars and French paper and comparing it with the extant literature, Shipman has come to an intriguing conclusion: that humans' comparative evolutionary fitness owes itself to the domestication of dogs.
Yep. Man's best friend, Shipman suggests, might also be humanity's best friend. Dogs might have been the technology that allowed early humans to flourish.
Shipman analyzed the results of excavations of fossilized canid bones -- from Europe, during the time when humans and Neanderthals overlapped. Put together, they furnish some compelling evidence that early humans, first of all, engaged in ritualistic dog worship. Canid skeletons found at a 27,000-year-old site in Předmostí, of the Czech Republic, displayed the poses of early ritual burial. Drill marks in canid teeth found at the same site suggest that early humans used those teeth as jewelry -- and Paleolithic people, Shipman notes, rarely made adornments out of animals they simply used for food. There's also the more outlying fact that, like humans, dogs are rarely depicted in cave art -- a suggestion that cave painters might have regarded dogs not as the game animals they tended to depict, but as fellow-travelers.
Shipman speculates that the affinity between humans and dogs manifested itself mainly in the way that it would go on to do for many more thousands of years: in the hunt. Dogs would help humans to identify their prey; but they would also work, the theory goes, as beasts of burden -- playing the same role for early humans as they played for the Blackfeet and Hidatsa of the American West, who bred large, strong dogs specifically for hauling strapped-on packs. (Paleolithic dogs were big to begin with: They had, their skeletons suggest, a body mass of at least 70 pounds and a shoulder height of at least 2 feet -- which would make them, at minimum, the size of a modern-day German Shepherd.) Since transporting animal carcasses is an energy-intensive task, getting dogs to do that work would mean that humans could concentrate their energy on more productive endeavors: hunting, gathering, reproducing.