Being picky eaters gave modern humans an advantage over Neanderthals

New tooth wear analysis suggests modern humans were more innovative in maintaining their diets in different environments.

You can learn a lot about a person by their teeth. Molar wear research conducted by Sireen El Zaatari and her colleagues, published today in PLOS, suggests Neanderthals ate mostly meat in the open steppe and relied more heavily on plants in forested areas, whereas modern humans’ diets were more selective and less environmentally driven. She tells us how she came to her results, and how humans’ different outlook on food helped them outlast their Neanderthal neighbors.  

ResearchGate: You studied Neanderthal and modern human tooth wear to determine how each group adapted their diets to changing climates. What did each group eat?

Sireen El Zaatari: If you want to generalize to the group level, Neanderthals and modern humans ate similar foods. Both groups' diets were comprised mostly of meat which was supplemented by plants. Yet, the proportions of meat to plant foods within each group varied based on different factors. These factors are the significant finding. For the Neanderthals, dietary variability was closely correlated with environmental variability. In open, cold steppe habitats Neanderthals largely focused on meat, whereas they increased their consumption of plants with the increase in tree cover, and thus plant resources, in the landscape. For modern humans, dietary variability appears to have been less correlated with environmental changes compared to the Neanderthals. Within the modern human sample, the greatest shift in diet that we see is temporal, that is between the earlier (Aurignacian and Gravettian) and late (Magdalenian) parts of the Upper Paleolithic. This shift involved a substantial increase in the consumption of hard plant foods.

RG: What do these diet variations tell you about how humans and Neanderthals adapted to changing climates?

El Zaatari: The different patterns of dietary changes between Neanderthals and modern humans show that these two groups had different dietary adaptation strategies to the climatic fluctuations of the Ice Age. The Neanderthals appear to have followed an opportunistic strategy, consuming what was widely available and easily accessible in different environmental settings. Modern humans, on the other hand, appear to have been more selective when it came to their diet. They also seem to have been willing to invest more effort in accessing food resources in their environment. For example, in open, cold steppe habitats, modern humans consumed substantially more plant foods than Neanderthals, whose diet consisted almost exclusively of the more abundantly available animal meat in these conditions. A selective dietary strategy is more difficult to maintain in changing environments, and Upper Paleolithic technologies probably aided modern humans in exploiting their preferred resources in spite of changes in environmental conditions.

RG: Where did the molars you examined come from?

El Zaatari: The molars came from a total of 52 individuals from 37 sites spread across Europe and the Levant. These teeth are kept at museums and institutions in 12 countries.

RG:  What were the major tooth wear characteristics you looked for to determine which foods were eaten?

El Zaatari:
Several attributes are used to characterize the surface texture of the teeth. The first is complexity, which measures the change in surface roughness, is a proxy for food hardness. The scale of maximum complexity identifies the scale at which the surface is most complex and reflects the size of the abrasive particles in the diet. Anisotropy, which measures the orientation of surface texture, is a proxy for food toughness. Textural fill volume, which measures the size and depth of wear features, provides a second indication of the size of abrasive particles in the diet. And finally heterogeneity, which measures the level of variability in complexity across the surface, is related to the level of variation in foods eaten. These attributes can all be linked to the properties of food and specific diets based on the microwear textures of species and groups with known diets.

RG: Your study suggests that maintaining their diets may have given modern humans an advantage over Neanderthals in changing climates. Why would that be?

El Zaatari:
The Neanderthals’ opportunistic dietary strategy gave them the necessary flexibility to survive in the changing climates of the Ice Age for more than a hundred thousand years. But, the arrival of modern humans into their geographical range would have probably subjected the Neanderthals to an extra survival pressure. Modern humans' more selective and less environmentally driven, and thus more stable, dietary strategy would have allowed them more efficient exploitation of dietary resources, and therefore maybe also given them an advantage over the Neanderthals.

RG: Many people today follow a “Paleo” diet, eating exclusively meat, vegetables, fruit, nuts. According to your results, what would a Paleolithic diet really look like?

El Zaatari:
The real Paleolithic diet, whether for Neanderthals or modern humans, consisted predominantly of meat and was supplemented by different plant foods, including roots, tubers, seeds, nuts, etc. The ratio of meat to plants was not the same for the different populations, nevertheless meat continued to form the bulk of the diet for all populations. I think the “Paleo” diet is close to the diet of the Paleolithic people in terms of general food categories. One just has to keep in mind that during the Paleolithic none of the domesticated fruits and vegetables we eat today existed. If you wanted to follow a real “Paleo” diet, then you’d have to stick with the wild varieties.

Featured image courtesy of Adibu456.