Were Neanderthals Culturally Modern Humans? - David Reich

David Reich opens by suggesting that the conventional framework for understanding the relationship between archaic and modern humans may be fundamentally flawed. The standard model positions Neanderthals and Denisovans as descending from a common ancestor roughly 500,000–600,000 years ago, with that lineage separating from modern human ancestors around 700,000–800,000 years ago.

However, Reich draws attention to compelling evidence of interbreeding events occurring approximately 200,000–300,000 years ago, in which modern humans contributed DNA to the ancestors of Neanderthals. This gene flow accounts for roughly 5% of the Neanderthal genome, a finding supported by multiple studies.

Reich notes an intriguing tension: while the archaeological record suggests Neanderthals and modern humans are behaviorally and culturally more similar to each other than either is to Denisovans, the genetic evidence — particularly following the 2010 sequencing of the Denisovan genome — clearly shows that Denisovans are genetically closer to Neanderthals than to modern humans. This overturned the long-held assumption that Neanderthals were the closest relatives of modern humans.

Raising a provocative hypothesis, Reich proposes that the most accurate way to conceptualize Neanderthals may be as 'culturally modern humans,' even though genetically they are predominantly Denisovan. This reframing invites a reconsideration of how cultural and genetic lineages can diverge, and what that means for our understanding of human evolution.