Human evolution: savannah theory fading (Introduction)

by David Turell , Wednesday, March 05, 2025, 18:57 (14 hours, 16 minutes ago) @ dhw

Savannah theory fading

DAVID: 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?

DAVID: Sapiens appeared 300,000 years ago, just as Neanderthals did ~600,000 years ago. All new forms simply appear. The interspecies mating helped make the sapiens we know. I don't understand your problem.

dhw: You claim that the savannah theory is “fading”. The savannah theory, as if you didn’t know, is that sapiens originated when a group of apelike creatures descended (for whatever reason) from African trees and took to life on the grassy plains. I needn’t go into the details concerning the advantages of bipedalism and all the later refinements. The articles you have presented here give no indication whatsoever of how the new species might have formed, and you are even claiming that “new forms simply appear” as if there was no possible reason for them doing so. ...

Your previous articles told us how we spread around Africa “via mating among populations in different African regions and habitats, including West Africa’s rainforests.” No indication at all about how we originated, and therefore no case made against the savannah theory.

DAVID: The case against the savannah theory alive and well:

https://www.nytimes.com/2025/02/26/science/early-humans-rainforests.html?campaign_id=34...

QUOTES: For generations, scientists looked to the East African savanna as the birthplace of our species. But recently some researchers have put forward a different history: Homo sapiens evolved across the entire continent over the past several hundred thousand years.

If this Africa-wide theory were true, then early humans must have figured out how to live in many environments beyond grasslands. A study published Wednesday shows that as early as 150,000 years ago, some of them lived deep in a West African rainforest.

Dr. Scerri and her colleagues suggested that for hundreds of thousands of years, our forerunners lived in isolated populations across Africa, periodically mixing their DNA when they came into contact.

dhw: We’re off again. All the articles tell us that sapiens lived in many different environments. But that would have been AFTER the species came into existence. All your articles make the same point: Sapiens spread far and wide.

DAVID: a paradigm is fading. Sapiens were everywhere in Africa, not just the savannahs. Your pleas for origins of sapiens is not the issue. We evolved from older hominin forms, why and ware still unknown.
And:
DAVID: Sapiens exact origin is totally unknown. I doubt we will ever know.

dhw: The savannah paradigm deals exclusively with the origin of sapiens, so how can you say the origin is not the issue and the paradigm is fading? One might just as well say the exact origin of life is totally unknown, you doubt whether we will ever know it, and therefore the God paradigm is fading. Would you agree?

If sapiens fossils appear at the same ancient time all over Africa the savannah theory makes no sense. We can conclude various different populations of Erectus all over Africa evolved into Sapiens in the same time frames. This means pre-Erectus forms were also all over Africa, not just in savannahs.