The divisibility of human ancestry

The class human or H. sapiens refers to a set of individuals. On the grand scale it’s really not all that clear and distinct. When do “archaic” humans become “modern” humans? Taking into account human variation, what is a “human universal”? A set of organisms are given a name which denotes the reality that they may share common ancestry, and interact behaviorally, and are potential mates. But many of these phenomenon are fuzzy on the margins. Many of the same issues which emerge in the “species concept” debates are rather general up and down the scales of natural complexity. A similar problem crops up when we conflate the history of genes with the history of populations. Such a conflation has value and utility to a first approximation. The story of mitochondrial Eve was actually the history of one particular locus, the mitochondrial genome. But it did tell us quite a bit about the history of the human species, even if in hindsight it looks as if some scientists overinterpreted those findings. One of the major issues I’ve noticed over the past year, with the heightened likelihood of …