Human evolution: savannah theory fading (Introduction)

by dhw, Wednesday, March 12, 2025, 10:57 (53 days ago) @ David Turell

DAVID: I think God created us. No natural need for our big brain has ever been demonstrated.

dhw: Our big brain, which you now seem to accept as having evolved from earlier brains (as opposed to your God having performed one of his many operations on our sleeping ancestors), has clearly given us advantages in the great dog-eat-dog battle for survival, which you accept as an explanation of evolution’s history.

DAVID: A non-answer to the issue of what natural requirements caused our brain development?

We’ve been over this a hundred times. An example: The hunter gets injured when trying to kill his prey from close up. New concept: maybe he can design a weapon to do the killing from a distance. The brain now has not only to work out something entirely new, but also has to send new massages to the body to implement the new concept. In modern times, we know that implementing new concepts requires new complexification of the brain (illiterate women, taxi-drivers etc). The early brain’s capacity for complexification was limited, and so it required new cells – hence expansion. Cause and effect all the way through until the brain (sapiens) could expand no further and complexification took over. Remember?

DAVID: Monkeys and great apes have been here relatively unchanged for six million years +/-. Then 'Why us'? Yes, the God designed hominin and homo forms whose attributes were formed in part by their climates. 'Same timing' of homos/sapiens fossils everywhere demotes the savannah theory to one proposal from limited evidence, which turns out to be a part of the whole. With pre-human and human activity everywhere we cannot know where sapiens first evolved. With my God theory, it could have occurred in several places relatively simultaneously.

dhw: Yes, the savannah theory is just one proposal and all proposals are made from limited evidence, because if there was unlimited evidence, there would be nothing to discuss! Let us remember that your God theory is not a natural progression of cause and effect but an intervention. All you have done now is expand your theory to your God operating on several groups instead of one.

DAVID: Right. I view the Cambrian explosion and our brain as two strong examples of God in action.

Brain dealt with above. Cambrian open to discussion (new fossils being found all the time). But our subject here is the origin of sapiens: why is your divine surgery on groups of ancestors more likely in your eyes than a group of ancestors being forced from the trees, surviving in the savannah, and spreading far and wide into all sorts of environments?

Human evolution: Paranthropus robustus walked upright
A new fossil find in South Africa:

https://phys.org/news/2025-03-fossil-discovery-early-human-ancestor.html?utm_source=nwl...

QUOTE: "Paranthropus robustus was a species of prehistoric human that lived in South Africa about 2 million years ago."

DAVID: dhw worries about sapiens origin. All we can say is we evolved from one of the many ancestors we had. Homo ergaster, mentioned above, is considered to be a form of Erectus fossils so we can follow the line of development to some degree. Paranthropus robustus may not be in that line.

dhw: I’m not worried – just curious! I don’t think anyone who believes in evolution would deny that we evolved from our ancestors! But I must confess, I find the savannah theory a bit more convincing than your own theory that your God popped in and performed leg and hip (and brain) operations on a group of our ancestors - now expanded to several groups.

DAVID: As science in fossils advances with new findings, paradigms die. (Thomas Kuhn)

A possible answer to your brain and Cambrian paradigms, and for all we know, new fossils might support the savannah paradigm rather than your divine surgery paradigm.