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

作为一个生物物种，人类通过自然选择继续从基因上适应各种环境。然而，文化和生活方式的变化比这些生理变化发生得快得多，在某些情况下导致我们的生理和现代生活之间的不匹配。这个博士论文项目研究了过去两个种群（觅食者和农牧民）食物资源的差异如何导致新陈代谢中不同的遗传适应，以及这些适应如何与现代福祉和慢性疾病相关。研究人员推测，过去对驯化食品的基因适应可能会导致人口向现代饮食和生活方式过渡时，慢性健康问题减少。这项研究将有助于我们理解饮食在人类进化和适应中的作用，以及它对当代人群健康的影响。来自美洲印第安人的遗传、流行病学和文化数据对于理解基因组变异在混合人群现代福祉中的作用至关重要，这些数据将与参与者和利益攸关方以及科学界共享。这项调查将包括来自代表性不足群体的个人作为研究参与者和研究人员，建立和加强国际研究合作，并为研究生和本科生的学生培训做出贡献。以人类生物学、营养和分子人类学以及进化医学的文献为基础，提出的研究旨在(1)评估在两个具有不同生存策略（狩猎采集与农牧民）历史的营养转型后的美洲印第安人群体中，参与营养代谢的基因组区域是否被选择为不同的目标；(2)评估这些特征是否具有生存特异性，并与几种慢性疾病风险生物标志物的流行相对应。现在的问题是，相对较近的饮食变化是否对人类种群产生了进化影响，以及这些变化在多大程度上与营养转变后人群中慢性病的增加有关。这项研究将包括两个美洲印第安人群体：一个直到最近才在温带森林中从事狩猎采集，另一个长期在沙漠环境中从事农牧活动。研究设计将包括民族志田野调查，包括口述历史访谈、饮食和身体活动调查、血液测量和人体测量慢性疾病风险生物标志物，以及全基因组选择扫描。

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.