Our research focuses on three main areas of inquiry:
- Reconstructing diets of individuals and groups
- Establishing costs and benefits of consuming plant foods
- Improving methods for discovering ancient use of plants
Dietary Variation in Upper Pleistocene Hominins
The diets of Neanderthals and contemporaneous modern human groups is of considerable interest. Some have argued that Neanderthals were highly carnivorous, while modern humans had a more variable diet, but the use of plant foods by both groups is all but unknown. Using a combined isotope and microfossil approach, we are examining the diets of several Upper Pleistocene groups from across the Old World, seeking to identify species-level, geographic, and temporal variation.
Main investigators: Amanda Henry, Robert Power, Domingo Carlos Salazar Garcia
Main collaborators: Dolores Piperno (Smithsonian Institution), Alison Brooks (George Washington University)
Plant use by Australopiths
The consumption of certain plant foods has been suggested as one of the main features that distinguish the diets of robust and gracile australopiths, yet there are few ways for documenting the consumption of these foods. We are working to recover microfossils from the calculus of some Australopith individuals in order to possibly identify the consumption of these foods.
Main investigators: Amanda Henry
Main collaborators: Lee Berger, Edward Odes (University of the Witwatersrand)
Micronutrients in cooked food and models of human digestion
Cooking is thought to be one of the major shifts in human evolution. We seek to better explore availability of macro and micronutrients in wild plant foods during human consumption and digestion. We intend to test for changes in the availability of these nutrients from before and after cooking trials that will mimic the cooking techniques used by the Hadza from Tanzania, Africa.
Main investigators: Stephanie Schnorr
Main collaborators: Alyssa Crittenden (University of Nevada), Frank Marlowe (Cambridge University), Koen Venema (TNO Healthy Living)
Variability in South African plant foods
Many of our ancestors lived in very patchy or mosaic habitats, where they would have had access to a large number of different plant foods. The caloric and nutrient quality of these foods, as well as their processing costs, may vary significantly among habitats. In order to understand how and why hominins chose the habitats they did, we are studying the variation in food quality of potential plant foods in the Cradle of Humankind in South Africa.
Main investigators: Antje Hutschenreuther, Amanda Henry
Main collaborators: Matt Sponheimer, Oliver Paine (University of Colorado, Boulder)
Causes of dental wear
One of the major costs to plant food consumption is the resulting damage to teeth. In animals, the loss of the chewing surface usually shortly precedes the death of the individual. Our australopith ancestors had significant dental wear, and among the robust forms in particular this wear reaches extreme levels. However, the exact cause of this wear is still unknown. We are participating in a project to understand exactly how phytoliths, grit, and other particles cause dental wear, which will allow us to better understand what our ancestors ate, and what dangers they may have faced with each bite.
Main investigators: Amanda Henry, Jörg Watzke
Main collaborators: Peter Lucas (Kuwait University); David Strait (University of Albany).
Database of modern plant microfossils
Researchers wishing to use plant microfossils to explore ancient plant use currently must create their own database of modern plant microfossil forms. We seek to create, manage, and share a publicly-available database of microfossil shapes, and further to codify the terminology of plant starch grain forms.
Main investigators: Jörg Watzke, Antje Hutschenreuther
Preservation of microfossils in dental calculus
Plant microfossils are incorporated into the bacterial film on teeth, and become trapped in this matrix as it mineralizes. It is still unclear how much of an individual's diet is represented in the calculus. Are all plants equally preserved? How many years are represented in the diet? We are exploring these questions by comparing the known diets of human and primate populations with the evidence preserved in their calculus.
Main investigators: Chelsea Leonard, Robert Power
Main collaborators: James O'Connell, Layne Vashro (University of Utah); Christophe Boesch (MPI-EVA Primatology)
Several biotic and abiotic agents may remove starch grains from the archaeological record, or change their morphology. We are exploring how native and gelatinized starches are preserved in soils and on buried stone tools in a variety of environmental settings, and how starches respond to various experimental conditions that mimic the process of aging.
Main investigators: Cynthianne Debono Spiteri