December 27, 2010 | 6
Ancient humans’ lax dental hygiene has been a boon for researchers looking for clues about early diets. Traces of fossilized foodstuffs wedged between Neandertal teeth have revealed plentiful traces of grains and other plants, supporting the theory that these heavy-browed humans were not just meat-eaters.
"Many researchers have proposed biologically or technologically mediated dietary differences" between modern humans and Neandertals as a key cause of the latter’s extinction, and "some scenarios have focused on the apparent lack of plant foods in Neandertal diets," a team of researchers noted in a new study. Scattered evidence has placed plant products on the scene of Neandertal sites, but these traces had been "fragmentary and not always unequivocally linked to diet."
Fortunately for paleobiologists, the mineralization process quickly "traps and preserves many components of the oral environment, including bacteria and food particles," leaving traces of Middle Paleolithic meals in the mouths that ate them.
After analyzing a selection of these particles from European and Middle Eastern Neandertal dental remains, the team found "direct evidence for Neanderthal consumption of a variety of plant foods." Researchers examined content found on seven teeth from three individuals—two unearthed in Belgium and one in Iraq. The study, led by Amanda Henry of the Center for the Advanced Study of Hominid Paleobiology, was published online December 27 in Proceedings of the National Academy of Sciences.
Some of the Paleolithic snacks seem to have included legumes, date palms and grass seeds. The grasses were from the Triticeae group, which includes wild varieties of barley, rye and wheat relatives.
In addition to profiling the types of found-foods these ancient humans were consuming, the researchers were also able to assess some of the preparation methods, which included cooking. This culinary step "represents a significant shift in human behavior, by improving the nutritional quality of plant foods and potentially altering the social organization of human groups," the researcher noted.
From the individual from the Iraq site (Shanidar Cave), for example, the team found that 42 percent of the recovered starch was from cooked materials, though Henry and her colleagues "expect that the actual proportion of cooked foods within the diet of this individual was probably much higher." To better assess starch grains from the samples, the researchers tried cooking similar plant products and found that heating the starches for more than half an hour rendered them largely unidentifiable, and thus they would not have been categorizable in fossil form.
The new findings suggest, "an overall sophistication in Neanderthal dietary regimes" and that "Neanderthals were capable of complex-food gathering behaviors that included both hunting of large game animals and the harvesting and processing of plant foods," the researchers concluded. Thankfully for the researchers, these early humans’ tool selection did not likely include floss.
Image courtesy of iStockphoto/Acik