Human evolution: savannah theory fading (Introduction)

by David Turell , Sunday, March 02, 2025, 17:20 (4 days ago) @ dhw

DAVID: The 300,000 years ago proviso tells us this discussion is about sapiens. But it roughly covers intermating with Neaderthals and Denisovans.

dhw: In that case, it tells us nothing about the origin of sapiens. So how does intermating come to mean the savannah theory is fading?

DAVID: You are disconnecting the early quotes in the article. This interbreeding was a late discussion not related to the earlier evidence of the study.

dhw: The earlier quotes only tell us that humans lived in forests earlier than we had previously thought. We are then told that sapiens evolved via mating in DIFFERENT African habitats, including West Africa’s rainforests. Who mated with who, and how does this come to mean that the very first sapiens did not evolve from a particular group that ventured forth into the savannah, and then ventured forth into different habitats as they multiplied?

DAVID: It is all from single studies of single spots.

dhw: And all the studies involve sapiens living and mating in forests. They do not tell us how sapiens evolved in the first place.

DAVID: Another article: https://www.nature.com/articles/s41586-025-08613-y

QUOTE: “The secure attribution of stone tool assemblages with the wet forest environment demonstrates that Africa’s forests were not a major ecological barrier for H. sapiens as early as around 150 ka.
"Most importantly, however, our results confirm a deep-time connection between human evolution and tropical forest biomes, opening up a new chapter in the human past in which our species occupied dense, wet tropical forests much earlier than widely thought.

DAVID: based on this evidence we weren't forced out into savannahs.

dhw: This evidence tells us that sapiens was already sapiens when he lived in the forests. It tells us nothing about how sapiens first became sapiens.

DAVID: Does that matter? The argument is did savannahs force sapiens evolution? What I presented says 'no'.

dhw: What you presented says no such thing. It only tells us that sapiens lived and mated in forests as well as elsewhere, and did so earlier than we thought. But perhaps you have left out a passage which rejects the savannah theory?

This quote might help you:

"The new findings also strengthen an argument that H. sapiens evolved roughly 300,000 years ago via mating among populations based in different African regions and habitats, including West Africa’s rainforests. Even around 150,000 years ago, “when these groups coalesced, their exchanges shaped the course of our evolution and likely contributed to the success of our species,” Scerri says."