Did Humans and Wolf Dogs Make Neanderthals Perish?

A new book says wolf dogs gave early modern humans an evolutionary advantage.

Posted Mar 16, 2015

In her provocative new book, The Invaders: How Humans and Their Dogs Dove Neanderthals to Extinction, Penn State paleoanthropologist Pat Shipman attributes the demise of Neanderthals around 40,000 years ago to early modern humans and their "wolf-dogs."  In her view, early modern humans, the most destructive invasive species on the planet, blasted into Europe and made straight for the biggest game in town—mammoths—conjuring along the way wolf-dogs, animals neither fully wolf nor quite yet dog, to help them in the hunt.  
 
Thus, she hopes to explain one of the great mysteries of prehistory: What happened to Neanderthal, an apparently successful species of big-game-hunting hominin, who vanished without a trace shortly after the appearance of modern humans in Europe? Shipman plows through a thicket of dates and revised dates in an effort to understand and explain the disappearance of Neanderthal, who was so close to our forebears genetically that they are by some experts considered one species. 
 
Wolf-dogs allowed early modern human hunters to obtain more game more quickly, over a wider area than Neanderthals, Shipman says. They assisted early modern humans in the hunt for mammoths, she says, tracking and holding the massive creatures at bay, so hunters armed with their new spear throwers could bring them down.  They also, she says, protected the kill and camp from scavengers and thieves and hauled butchered meat back to camp.  Shipman’s story makes for a dramatic and compelling narrative, but it also awaits additional proof.  
 
Shipman agreed to answer a few questions raised by her book.
 
Mark Derr: Your wolf-dogs bear a remarkable resemblance to “dogs” in terms of the behaviors you propose for them and their relationship to humans. In fact, you argue that wolves and humans were implacable competitors if not enemies. In that light, why not just call them dogs?

Pat Shipman: First of all, I'm afraid if I say "dogs" people will think of poodles or retrievers. Second, we don't yet know if they were ancestral to modern dogs, since the mtDNA lineage of the Pleistocene wolf-dogs or canids has not been found in modern dogs or wolves. I wrestled long and hard with what to call these animals based on what we know. Wolf-dogs is a somewhat ambiguous term to use, but it was the best I could come up with. Also, the first domestic dog was probably not entirely like modern dogs behaviorally. 
 
Mark Derr: You appear to agree with the assessment of Olaf Thalmann (2013) and an international collection of canine geneticists that those mammoth hunting wolf-dogs did not contribute to modern dogs but represent an early failed attempt at domestication. By my calculation, they existed for around 20,000 years—not bad for a failure. Why and when did they go extinct? That domestication seems to have happened at least twice seems to say more about the natural affinity of humans and wolves than their unnatural enmity.

Pat Shipman: I don't entirely agree with Thalmann and colleagues, though I have great respect for their knowledge and research. Suggesting that the wolf-dogs might have been a first, unsuccessful attempt at dog domestication is a more conservative position than saying these were the first domestic dogs ancestral to all others, though. In my heart of hearts, I suspect we may find modern-day canids with that mtDNA lineage. And if we don't, since mtDNA lineages go extinct at a phenomenal rate, what does that prove? I am trying to present evidence-based ideas—or at least hypotheses that are testable—rather than my suspicions. And I do think it would be fascinating if dog domestication happened several times independently. I haven't thought about domestication as something that might have happened repeatedly, with varying success.  
 
Mark Derr: How, when, and why did this alliance of wolf and human take shape, especially in light of your apparent belief that wolves and humans have always been competitors if not implacable foes? 

Pat Shipman: I would say competitors and not necessarily implacable foes, though there are a number of people in the American West with whom I have talked at some length who are implacable foes of wolves. Clearly our ancestors and Pleistocene (and modern) wolves favor the same prey and the arrival of a new apex predator (early modern humans) would have shaken the ecosystem up a good deal. Whenever it occurred, an alliance between humans and some sort of doggy-wolfy animal proved extremely advantageous for both participants. But I do not believe anyone decided they needed a good hunting dog and thought they could get one by keeping a wolf pup. 
 
Mark Derr: Last April in PLoS One, Paola Villa, of the University of Colorado Museum and Wil Roebroeks, of Leiden University, The Netherlands, published a major review of theories for Neanderthal’s demise and concluded that it never happened. Rather, they say, “The Neandertal [sic] demise appears to have resulted from a complex and protracted process including multiple dynamic factors such as low population densities, interbreeding with some cultural contact, possible male hybrid sterility and contraction of geographic distribution, followed by genetic swamping and assimilation by the increasing numbers of modern immigrants.”  What is wrong with that view? 

Pat Shipman: They are probably right that all of those factors had a role to play. What they did not consider—and I wish they had—was what happens when a new invasive predator enters an ecosystem.

Mark Derr: You refer repeatedly to an invasion of Europe by early modern humans. That implies some intentionality for conquest, which suggests some sociopolitical structure capable of organizing a military campaign. Is that a fair assessment? If so, what form did that organization take? 

Pat Shipman: I use "invasion" and "invasive" not to suggest intentionality or military conquest on the part of modern humans, any more than kudzu intended to invade the Americas. It does imply a more dynamic impact than other usage would suggest, however, and that is deliberate on my part.  

Mark Derr: Your book raised the immediate question: What happened to Homo erectus? Could that be next?

Pat Shipman: That is not my intention right now, but I always have a lull between books until some new idea or question grabs me.  

Mark Derr: Thank You.