The UNLV Anthropology department presents "Methods in Assessing the Role of Plants in Human Diet," a colloquium by Ms. Stephanie Schnorr, of the Max Planck Institute for Evolutionary Anthropology.
Diet is a special and often very personal topic in modern human culture. Food is an integral aspect of our daily lives, and yet there is enormous disparity in the type and amount of attention we devote to it. This may be the result of modern industrialization trivializing efforts to obtain food for the majority of westernized developed countries. However, cultural boundaries can still be demarcated by the foods consumed by a community. Participants of particular groups, religions, ethnicities, and even nations, exude a sense of identity with their cuisine. Food and its acquisition were undoubtedly important for human ancestors as it is one of the most significant selective pressures any organism faces in the environment. Ecological niches are largely predicated on dietary ecology and offer much information for understanding species diversity. But how do we learn anything about human evolution through diet when our diet ecology encompasses the planet? In fact it may be this ultimate omnivore opportunism that characterizes the evolutionary trajectory of humans, but at what level are we biologically adapted to our diets? These and other questions are central to the theme of my Ph.D work in which Schnorr looks at the biological contribution of underground storage organs (or tubers) in the Hadza hunter-gatherer diet using in-vitro digestion techniques. She models digestion from comminution to hind-gut fermentation to assess the availability of nutrients (bioavailability) from tubers, which are a major plant resource for the Hadza living in Sub-Saharan East Africa. Schnorr also tested whether brief roasting, a form of food processing practiced by the Hadza, has any effect on the bioavailability of tuber nutrition. Results suggest that the food ecology poses a dilemma for human foragers in two respects: the first is to find good quality tubers that are high in calories or micronutrients, and the second is to consume these tubers in a way that maximizes their nutritional yield without the forager expending undue energy. The next phase of this work is to model fermentation in the colon using gut microbial populations to examine the contribution of the microbiome to host nutrition.