Razib Khan is a geneticist and Substacker. He joins the podcast to talk about what genetics can tell us about the human past and the progress made in his field over the last few decades. The conversation touches on population structures in Europe, India, China, and the Western Hemisphere, along with Neanderthal and Denisovan admixture among different races and how different fields define what it means to be human. Richard and Razib discuss questions including how Indian castes were able to remain genetically distinct for such a long time, the original "great replacement" in Europe, and the connection between state capacity and genetic heterogeneity, as can be seen in India and China. The conversation then shifts towards a discussion about their experiences in academia, the recent radicalization on college campuses, and growing up as minorities in the United States.