Did We Kill Off Another Species of Humans Ten Thousand Years Ago?

[wnylib]

5. More problems with this article

Longrich claims that there were no major geological or climate events to account for human evolutionary changes, extinctions, and developments. But climate changes played a major role in human evolution. Periods of glaciation changed forests to grasslands (around the time that our ancestors left trees to live upright on the ground). Grasslands became deserts and separated our African ancestors from each other to evolve separately while still in Africa, some to extinction and others toward more upright and human-like ancestors of us.

Climate changes favored those who could adapt to various habitats via tool development, broadened diets, and social groupings for cooperation and interdependence, the ability to make clothing, shelters, etc. Habitat and local resources influenced evolution. So did isolations of gene pools due to geographical separation by habitat changes. But at the edges of a habitat, our ancestors sometimes encountered other evolving ancestors and intermated enough to maintain enough similarity among various evolving homonin forms to allow fertile intermixing.

Sometimes localized or widespread climate events caused extinctions of large groups of one type of hominin, e.g. flooding, drought, or warming that brought insects, germs, and disease. Genetic bottlenecks occurred, nearly extinguishing a group. Later interbreeding would finish them off as a distinctly separate homonin form.

Longrich assumes that culture in the form of artwork was a modern human (HS) invention. But we know that HN at least (and maybe others) had decorative beads and ritual burials that included placement of flowers. Maybe it was HS who learned from HN sometimes.