Anthropology.net

Last month’s annual meeting of the Paleoanthropology Society hosted a talk by Amanda Henry, a graduate student at George Washington University. She analyzed the microfossils of plant material found in the dental plaque on Neandertal teeth from Shanidar, Iraq.

What is dental plaque? Much to the chargin of dentists out there, the composition and origin of dental plaque isn’t known to most. We may know it simply as something we work so diligently every morning and evening to brush away. Plaques are a type of biofilm. Bioflims are an amalgamation of microorganisms, who excrete a goo to protect themselves and allow them to stick together. Inside this gooey microecosystem, these crafty microorganisms also trap food particles to use as energy sources for themselves. If left untreated on teeth, these plagues of microorganisms grow and the amount of anaerobic respiration increases reciprocally. One of the byproducts of anaerobic respiration are acids which consequently demineralize adjacent tooth surface, and form cavities. That’s why you should brush and floss twice a day.

In September of last year, I shared news of how Neandertals may have also been aware of their dental hygiene. We saw how they may have used toothpicks. But, they didn’t have Sonicare toothbrushes and dental hygenists scraping away plaques every six months. Inevitably, some plaques persisted and in the teeth of a 35,000 year old Neandertal (Shanidar III). Amanda Henry was able to recover plant material. Henry gets into a discussion on how this showed evidence that Neandertals ate plants.

Not too novel, but definitely important to finally confirm. Much like the conclusion that Neandertals were mobile, plant consumption among them is one of those things we knew was most likely the case. How? Based upon the dental anatomy and morphology of the teeth, we knew they had very robust molars to grind down plant materials. Comparison to extant apes, like chimpanzees and humans, confers that Neandertals may have also been omnivorous. Furthermore, the results of a 2006 Science paper, an isotopic analysis of hominid teeth revealed that hominids ate a variety of foods.

I was gonna get into a discussion on how this one finding doesn’t mean all Neandertals died without brushing after a nice yummy salad meal. Nor does it elucidate how many times this Shanny-3 ate his greens. But, Henry acknowledges that and cautions that Shanidar III is only one fossil and does not provide enough evidence to make conclusive statements about the entirety of the Neandertal diet. I commend her on that. Even with this disclaimer, Matt Sponheimer, lead author of the 2006 isotopic analysis still wanted to have the last word, rehashing that,

“…[this study] does not indicate whether an individual Neandertal ate plants once or a thousand times.

It also doesn’t show the relative proportions of a food type in the individual’s diet.

“Thus it is but one flawed technique of paleodietary reconstruction among many,” he said.”

While we consider Matt’s critiques, let’s also consider one I thought of — The most simple explanation of the presence of plant material in plaques on the teeth means that this Neandertal chewed plants. Without an isotopic comparison of the recovered plant material to Shanidar 3’s teeth, we don’t know if this guy was really digesting the plant. Maybe Amanda Henry is looking into that…

One last thing, if Shanidar 3 really was eating plants, did his foot injury have anything to do with this? See, Shanidar III has a degenerative joint disorder in his foot. That woulda caused a lot of pain and limited his mobility. Would that have anything to do with why he was chewing on sedentary food sources?

Trinkaus, E. (1982). The Shanidar 3 Neandertal. American Journal of Physical Anthropology, 57(1), 37-60. DOI: 10.1002/ajpa.1330570107

Sponheimer, M., Passey, B.H., de Ruiter, D.J., Guatelli-Steinberg, D., Cerling, T.E., Lee-Thorp, J.A. (2006). Isotopic Evidence for Dietary Variability in the Early Hominin Paranthropus robustus. Science, 314(5801), 980-982. DOI: 10.1126/science.1133827