Quantifying the role of cultural forces in shaping human genetics

As human genomes are sequenced at an increasing rate, the histories of populations have become progressively clearer, informing our understanding of evolution. However, alongside genes, people inherit knowledge and practices from their communities, and the interactions between genetic and cultural evolution remain an understudied aspect of human evolution. Genes and culture are inherited by separate means, but they become intertwined in the course of our lives, so our understanding of human history will be incomplete unless it incorporates cultural context. To connect human cultural and biological histories, we will explore the two-way interaction between culture and populations, using both computational models and empirical data analysis at multiple spatial scales. We propose to examine how culture affects interactions within and between populations, and how relationships between populations affect cultural history.
In multiple contexts, we will address how aspects of culture, such as homophily or kinship norms, affect human genetic variation. For example, marriage customs and preferences for cultural similarity can reinforce the genetic boundaries between populations. Our previous research on gene-culture interactions and our development of synthesized datasets make us uniquely poised to empirically test such relationships. By jointly analyzing recently compiled genomic datasets, ethnographic records of interpersonal relations, and digitized linguistic features, we propose to measure how culture has influenced populations and their evolution. Specifically, we develop statistical tools to ask: How is culture and language transmitted over thousands of years? How are these cultural trajectories affected by other aspects of culture, such as kinship practices or cultural divides? The results of these tests will enable studies of language and culture to inform human evolution and its genetic underpinnings, shedding new light on what makes us uniquely human.