Calculus is hard.
But it is worth studying because it is such a powerful tool.
You don’t think I’m referring to math, do you? I’m not. I’m referring to dental calculus, the hardened plaque that forms on teeth.
Recently, researchers from Australia and the UK studied the calculus scraped from the teeth of Neanderthals and compared it to the calculus taken from the teeth of modern humans and chimpanzees (captured from the wild) with the hope of understanding the diets and behaviors of these hominins.1 The researchers concluded that this study supports the view that Neanderthals had advanced cognitive abilities like that of modern humans. If so, this conclusion creates questions and concerns about the credibility of the biblical view of humanity; specifically, the idea that we stand apart from all other creatures on Earth because we are uniquely made in God’s image. Ironically, careful assessment of this work actually supports the notion of human exceptionalism, and with it provides scientific evidence that human beings are made in God’s image.
This study built upon previous work in which researchers discovered that they could extract trace amounts of different types of compounds from the dental calculus of Neanderthals and garner insights about their dietary practices.2 Scientists have learned that when plaque forms, it traps food particles and microbes from the mouth and respiratory tract. In the most recent study, Australian and British scientists extracted ancient DNA from the plaque samples isolated from the teeth of Neanderthals recovered in Spy Cave (Belgium) and El Sidrón (Spain). These specimens age-date between 42,000 and 50,000 years in age. By sequencing the ancient DNA in the samples and comparing the sequences to known sequences in databases, the research team determined the types of food Neanderthals ate and the microorganisms that infected their mouths.
Based on the ancient DNA recovered from the calcified dental plaque, the researchers concluded that the Neanderthals unearthed at Spy Cave and El Sidrón consumed different diets. The calculus samples taken from the Spy Cave specimens harbored DNA from the woolly rhinoceros and European wild sheep. It also contained mushroom DNA. On the other hand, the ancient DNA samples taken from the dental plaque of the El Sidrón specimens came from pine nuts, moss, mushrooms, and tree bark. These results suggest that the Spy Neanderthals consumed a diet comprised largely of meat, while the El Sidrón hominins ate a vegetarian diet.
The microbial DNA recovered from the dental calculus confirmed the dietary differences between the two Neanderthal groups. In Neanderthals, and in modern humans, the composition of the microbiota in the mouth is dictated in part by the diet, varying in predictable ways for meat-based and plant-based diets, respectively.
Did Neanderthals Consume Medicinal Plants?
One of the Neanderthals from El Sidrón—a teenage boy—had a large dental abscess. The researchers recovered DNA from his dental calculus showing that he also suffered from a gut parasite that causes diarrhea. But, instead of suffering without any relief, it looks as if this sick individual was consuming plants with medicinal properties. Researchers recovered DNA from poplar plants, which produce salicylic acid, a painkiller, and DNA from a fungus that produces penicillin, an antibiotic. Interestingly, the other El Sidrón specimen showed no evidence of ancient DNA from poplar or the fungus, Penicillium.
If Neanderthals were able to self-medicate, the researchers conclude that these hominins must have had advanced cognitive abilities, similar to those of modern humans. One of the members of the research team, Alan Cooper, muses, “Apparently, Neandertals possessed a good knowledge of medicinal plants and their various anti-inflammatory and pain-relieving properties, and seem to be self-medicating. The use of antibiotics would be very surprising, as this is more than 40,000 years before we developed penicillin. Certainly, our findings contrast markedly with the rather simplistic view of our ancient relatives in popular imagination.”3
Though intriguing, one could argue that the research team’s conclusion about Neanderthals self-medicating is a bit of an overreach, particularly the idea that Neanderthals were consuming a specific fungus as a source of antibiotics. Given that the El Sidrón Neanderthals were eating a vegetarian diet, it isn’t surprising that they occasionally consumed fungus because Penicillium grows naturally on plant material when it becomes moldy. This conclusion is based on a single Neanderthal specimen; thus, it could simply be a coincidence that the sick Neanderthal teenager consumed the fungus. In fact, it would be virtually impossible for Neanderthals to intentionally eat penicillin-producing fungi because, according to anthropologist Hannah O’Regan from the University of Nottingham, “It’s difficult to tell these specific moulds apart unless you have a hand lens.”4
But even if Neanderthals were self-medicating, this behavior is not as remarkable as it might initially seem. Many animals self-medicate. In fact, this phenomenon is called zoopharmacognosy.5 For example, chimpanzees will consume the leaves of certain plants to make themselves vomit, in order to rid themselves of intestinal parasites. So, instead of viewing the consumption of poplar plants and fungus by Neanderthals as evidence for advanced behavior, perhaps, it would be better to regard it as one more instance of zoopharmacognosy.
Medicine and Human Exceptionalism
The difference between the development and use of medicine by modern humans and the use of medicinal plants by Neanderthals (assuming they did employ plants for medicinal purposes) is staggering. Neanderthals existed on Earth longer than modern humans have. And at the point of their extinction, the best that these creatures could do is incorporate into their diets a few plants that produced compounds that were natural painkillers or antibiotics. On the other hand, though on Earth for only around 150,000 years, modern humans have created an industrial-pharmaceutical complex that routinely develops and dispenses medicines based on a detailed understanding of chemistry and biology.
As paleoanthropologist Ian Tattersall and linguist Noam Chomsky (along with other collaborators) put it:
“Our species was born in a technologically archaic context . . . . Then, within a remarkably short space of time, art was invented, cities were born, and people had reached the moon.”6
And biomedical advance has yielded an unimaginably large number of drugs that improve the quality of our lives. In other words, comparing the trajectories of Neanderthal and modern human technologies highlights profound differences between us—differences that affirm modern humans really are exceptional, echoing the biblical view that human beings are truly made in God’s image.