Human evolution: savannah theory fading (Introduction)

by David Turell , Tuesday, March 04, 2025, 16:52 (1 day, 16 hours, 32 min. 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.

The case against the savannah theory alive and well:

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

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.

“What we’re seeing is that, from a very early stage, ecological diversification is at the heart of our species,” said Eleanor Scerri, an evolutionary archaeologist at the Max Planck Institute of Geoanthropology in Jena, Germany, and an author of the study.

In the 20th century, after scientists found many fossils and stone tools in East African savannas, many researchers concluded that our species was especially adapted to life in grasslands and open woodlands, where humans could hunt great herds of mammals.

Only much later, the theory went, did our species become versatile enough to survive in tougher environments. Tropical rainforests appeared to be the toughest of them all. It can be hard to find enough food in jungles, and they offer lots of places for predators to lurk.

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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.

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Still, the researchers managed to gather a lot of clues. Dr. Ben Arous, an expert on geochronology, used new methods to estimate the age of the sediment layers. The oldest layer in which the researchers found stone tools formed 150,000 years ago.

The sediment also preserved wax from the surface of ancient leaves. Analyzing the chemistry of the leaf wax revealed that Anyama was a dense rainforest throughout its history. Even in the ice age, when the cool, dry climate shrank jungles across Africa, Anyama remained a tropical refuge.

Cecilia Padilla-Iglesias, an anthropologist at the University of Cambridge who was not involved in the new study, said that the work offered clear proof that people were living in those jungles — and that they were living there very early in the history of our species.

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many of the oldest artifacts discovered were massive chopping tools crafted from quartz. She speculated that the Anyama people used them to dig up food or hack their way through the rainforest.

“If you move a lot, you need tools to cut the trees that hinder your path,” Dr. Niang said.

The distinctive tool kit makes Dr. Scerri suspect that the Anyama people had already lived in the rainforest long before 150,000 years ago. “They’re not people who have just arrived,” she said. “These are people who had the time to adjust to their living conditions.”

Comment: 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.