Doctoral Dissertation Research: The effects of past dietary adaptations on modern populations

Indiana University, Bloomington IN

Investigators

Abstract

As a biological species, humans continue to adapt genetically to various environments through natural selection. However, cultural and lifestyle changes occur much more rapidly than those biological changes, leading in some cases to a mismatch between our biology and our modern life. This doctoral dissertation project investigates how past differences in the food resources of two populations (foragers vs. agropastoralists) may have led to different genetic adaptations in metabolism, and how those adaptations may relate to modern-day well-being and chronic conditions. The investigator hypothesizes that past genetic adaptations to domesticated foodstuffs could result in fewer chronic health problems when a population transitions to a modern diet and lifestyle. The study will contribute to our understanding of the role of diet in human evolution and adaptation, and its effects on well-being in contemporary populations. Genetic, epidemiological and cultural data from Amerindian individuals, which are crucial for understanding the role of genomic variants in modern well-being among admixed populations, will be shared with participants and stakeholders as well as the scientific community. This investigation will include individuals from underrepresented groups as both research participants and researchers, build and strengthen international research collaborations, and contribute to student training at the graduate and undergraduate levels. Grounded in the literature of human biology, nutritional and molecular anthropology, and evolutionary medicine, the proposed research aims to (1) evaluate whether genomic regions involved in nutrient metabolism have been differentially targeted by selection in two post-nutrition transition Amerindian populations with contrasting histories of subsistence strategies (hunting-gathering vs. agropastoralism) and (2) evaluate whether these signatures are subsistence-specific and correspond to the prevalence of several chronic condition risk biomarkers. The question arises as to whether relatively recent dietary shifts have had evolutionary consequences for human populations, and to what extent these are related to the rise in chronic conditions in post-nutrition transition populations. This study will include two Amerindian populations: one that until recently engaged in hunting-gathering in the temperate forest, and the other that has been long engaged in agropastoralism in a desert environment. The research design will comprise ethnographic fieldwork including oral history interviews, dietary and physical activity surveys, measurements of blood and anthropometric chronic condition risk biomarkers, and genome-wide scans for selection.