About 40,000 to 30,000 years ago, modern humans out-competed Neanderthals, and the Neanderthals became extinct. Some recent theories have speculated that Neanderthals had an inferior diet (predominately meat) that put them at a disadvantage. Evidence for plant foods is rare at sites occupied by Neanderthals, but this could be due to vagaries of preservation and insufficient attention to plant remains. In an ingenious study, Amanda Henry, Alison Brooks, and Dolores Piperno used microscopy to demonstrate that plants and cooked foods are present in dental calculus (the stuff the dental hygienist scrapes off your teeth) on the teeth of Neanderthals [Reference Henry, Brooks and Piperno1].
Henry et al. used brightfield and cross-polarized light microscopy to examine plant microfossils (starch grains and minute mineralized particles formed inside plants called phytoliths) trapped in dental calculus of Neanderthal individuals. The specimens were from known Neanderthal archeological sites in modern-day Iraq and Belgium—north-south extremes of the range of these people. The southern site was inland and mountainous, whereas the northern site was oceanic.
The evidence showed that Neanderthals in both environments included a spectrum of plant foods in their diets, including grass seeds, dates, legumes, plant underground storage organs (such as tubers), and other yet-unidentified plants. Importantly, several of the consumed plants had been cooked (see Figure 1). For example, the overall pattern of damage to the starch grains matches most closely with that caused by heating in the presence of water, such as during baking or boiling. Also, several of the identified plant foods would have required moderate to high levels of preparation. These lines of evidence indicate that Neanderthals were investing their time and labor in preparing plant foods in ways that increased their edibility and nutritional quality. Overall, the data suggest that Neanderthals were capable of complex food-gathering behaviors that included both hunting of large game animals (established in earlier studies) and the harvesting and processing of plant foods.
Figure 1: Ancient starches from the teeth of Shanidar III (bottom row) closely match those from Hordeum bulbosum, a wild relative of barley (top row). Figures b and e show the extinction cross, a distinctive feature of starch grains under cross-polarized light. The starches in c and f are partially gelatinized from cooking, indicating that Neanderthals cooked their food.
The studies of Henry et al. extend the known record of starch consumption into the Middle Paleolithic Age and indicate that starch grain analysis in dental calculus specimens will enable reconstructions of diet in a range of fossil specimens. So do we know how modern humans displaced the Neanderthals? No, but it was not because they didn't have a well-balanced diet.
