Long before the origins of agriculture, humans expanded across the globe, from the arid deserts of Australia to the frozen tundra of the Canadian Arctic. Surviving in this immense diversity of habitats depended not on specific genetic adaptations, but on large bodies of culturally transmitted know-how, abilities, and skills that no single individual could figure out in his or her lifetime (e.g., blowguns, animal tracking). Lacking local cultural knowledge, many an explorer has perished in supposedly “harsh” environments in which local adolescents would have easily survived (Boyd, Richerson, & Henrich, 2011a). Even among foraging societies, humans show an immense variety of social organizations, group sizes, kinship structures, and mating patterns: more diversity than the rest of the primate order combined (Henrich & McElreath, 2007). Ethnographically, this diversity is at least partially rooted in culturally-acquired and widely shared social rules. No other species depends on cultural information to this degree, and paleo-anthropological evidence increasingly suggests that culture appears early in the evolutionary history of our genus (Alperson-Afil et al., 2009; Brown et al., 2009). Overall, much theory and evidence now converges to indicate that we are an ultra-cultural species —unlike any other—whose brains, genes, and biology have long been shaped by the interaction between cultural and genetic evolution. Culture appears to have opened up entirely new evolutionary vistas not available to less cultural species.