How Homo naledi matters to our origins
Today’s humans all over the world derive most of their ancestry from African populations that lived before 100,000 years ago. The period from 350,000 to 100,000 years ago in Africa was the time when the initial population diversification of modern human groups happened. Until recently, most anthropologists thought that Homo sapiens was alone on the African continent during this critical time period. In 2013, our team working in the Rising Star cave system in South Africa uncovered the new species Homo naledi. Since that time, our team has described fossil material of this species from two distinct chambers within the cave system, and has been able to place the Dinaledi Chamber fossil remains between 335,000 and 236,000 years ago. The published material represents a minimum of 18 individuals, representing nearly all parts of the skeleton and all age stages. In this talk, I will give a brief introduction to the research team, cave system, and anatomy of this species. I will focus on several problems raised by this new discovery for understanding human origins. I will discuss the behavioral complexity evidenced in the Rising Star cave assemblages, and the implications of a multispecies African hominin community for understanding the archaeological record. I will also discuss the probability that H. naledi or its ancestors may already be known from other sites, and the implications of our recent understanding of hybridization and introgression in human origins.