Richard Wrangham, an anthropologist at Harvard, claims that hominids became people—that is, acquired traits like big brains and dainty jaws—by mastering fire. He places this development at about 1.8 million years ago. This is an appealing premise no matter who you are. For those who see cooking as morally, culturally, and socially superior to not cooking, it is scientific validation of a worldview: proof that cooking is literally what makes us human. For the rest of us, it means we have a clever retort the next time one of those annoying raw-food faddists starts going on about how natural it is never to eat anything heated above 115 degrees Fahrenheit.
There’s one problem with Wrangham’s elegant hypothesis: It’s hardly the scientific consensus. In fact, since 2009, when Wrangham explained his theory in the book Catching Fire, several archaeologists have come forward with their own, wildly divergent opinions about what is arguably the oldest intellectual property debate in the world. Who really mastered fire, in the sense of being able to create it, control it, and cook with it regularly? Was it Homo erectus, Neanderthals, or modern humans?
A brief primer on these species: H. erectus originated about 1.8 million years ago. These hominids were about as tall as modern humans, but probably hairier and definitely dumber. It’s thought that both Neanderthals and Homo sapiens evolved from H. erectus, with Neanderthals emerging about 600,000 years ago (and going extinct around 30,000 years ago) and modern humans emerging around 200,000 years ago (and still going strong). Neanderthals were shorter and had more complex societies than H. erectus, and they’re thought to have been at least as large-brained as modern humans, but their facial features protruded a little more and their bodies were stouter than ours. It’s thought that Neanderthals died out from competing, fighting, or interbreeding with H. sapiens.
According to Wrangham, H. erectus must have had fire—just look at their anatomy! H. erectus had smaller jaws and teeth (and smaller faces in general), shorter intestinal tracts, and larger brains than even earlier hominids, such as Australopithecus afarensis, for instance, who were boxier, more apelike, and probably duller. Wrangham argues that H. erectus would not have developed its distinctive traits if the species hadn’t been regularly eating softer, cooked food.
This hypothesis stems from a few modern observations. When you eat cooked food, you have access to many more calories than if you eat the same food raw. There are two reasons: Our digestive systems can extract more calories from a cooked steak (for instance) than a raw steak, and it takes much less energy to cook and eat a steak than to gnaw on a raw one for hours. Access to cooked food means a hominid no longer needs enormous teeth to break down all that raw meat and roughage into swallowable hunks, nor does it need as robust a digestive system to process it all. The combination of more calories and less complicated intestines means more energy can be devote to cogitating—hence H. erectus’ relatively big brains, which suck up a lot of calories. As evidence for his theory, Wrangham likes to point to the fact that modern-day humans can’t thrive on an all-raw diet—raw foodists tend to stop menstruating, precluding reproduction.
Wrangham’s theory is elegant, but the archaeological record is a little more complicated. There is definitely evidence of fire around 1.6 million years ago in what is now Kenya. But archaeologists dispute whether this was manmade or natural fire. Further complicating Wrangham’s hypothesis is evidence that hominids may not have brought fire with them when H. erectus moved out of Africa into Europe around a million years ago. If fire was as transformative and beneficial as Wrangham said it was, you’d think our ancestors would have brought it with them when they moved to colder climes—or died out if they were unable to do so.
If H. erectus didn’t bring fire mastery to Europe, who did? Archaeologists Wil Roebroeks of Leiden University in the Netherlands and Paola Villa of the University of Colorado Museum found evidence for frequent use of fire by European Neanderthals between 400,000 and 300,000 years ago. Roebroeks and Villa looked at all the data collected at European sites once inhabited by hominids and found no evidence of fire before about 400,000 years ago—but plenty after that threshold. Evidence from Israeli sites put fire mastery at about the same time. H. sapiens arrived on the scene in the Middle East and Europe 100,000 years ago, but our species didn’t have a discernible impact on the charcoal record. Roebroeks and Villa conclude that Neanderthals must have been the ones who mastered fire.
One of the beautiful things about the archaeological record is that archaeologists are always willing to debate about it. Attributing fire to Neanderthals is an overly confident reading of the evidence, according to archaeologist Dennis Sandgathe of British Columbia’s Simon Fraser University. Of course the number of campsites with evidence of fire increased between 1 million and 400,000 years ago, he says—the number of campsites, period, increased during this time in proportion with population growth. But that doesn’t mean the use of fire was universal among European hominids—there are plenty of Neanderthal campsites out there that show little or no evidence of fire, and Sandgathe has personally excavated some of them. What’s more, Sandgathe told me when I asked him about Roebroeks’ and Villa’s data, “We actually have better data than they do when it comes to Neanderthal use of fire.”