Human evolution: savannah theory fading; big brain (Introduction)

by dhw, Friday, March 21, 2025, 11:25 (13 days ago) @ David Turell

The human brain

DAVID:I have no idea how God enlarges brains or increases the complexity. But each increase provides for the present and future needs.

dhw: How else could he do it without some kind of individual operation? Don’t you think it would be less of a chore for him if he just created a mechanism that would perform the same functions? Your second sentence fits in perfectly with the history I have presented: each enlargement is a response to new requirements that exceed the present capacity for complexification; the same size is maintained till the next requirement that exceeds the capacity, and so on until we reach sapiens, and as further expansion is not possible, it is enhanced complexification that copes with all future requirements. You’ve got it! (dhw's bold. See later.)

DAVID: Yes, God put a complexification process into each stage of brain development.

He would only have needed to do so at the beginning, as it has been in use ever since with every stage. I’m delighted that you now agree with the above, just as you did when we discussed it some time ago.

DAVID: The Erectus brain covered many complex problems, but could not handle today's requirements. Even though ours is 315,000 years old it works just fine. That is anticipation of needs.

dhw: In fact, the erectus brain gradually expanded until it came very close to our size. Something triggered the final expansion to our size, and from then on, complexification has coped with all new needs, as it did with every other species until additional cells were required. Each expansion is a response to new needs; the additional cells are not the result of crystal-ball gazing and then hanging around for thousands of years, in our case waiting to invent railways and rockets! They are in constant use, and complexify as and when required to do so. Currently demonstrated by the examples of the illiterate women and taxi-drivers.

DAVID: You want natural evolution. I have God eh designer.

And now you try to ignore your own agreement and all the above arguments by introducing a totally false representation of my approach. Back we go. Read the bold in my first statement: “Don’t you think it would be less of a chore fo him if he just created a mechanism that would perform the same functions?” All my theories allow for God the designer – in this case, as you have agreed, he would have designed the mechanism for complexification (and of course I include enlargement). Please stop pretending that my theories are atheistic, even though you keep agreeing with them!

The savannah theory

Human evolution: adding to our genome

QUOTE: "The ancestors of all modern humans split off from a mystery population 1.5 million years ago and then reconnected with them 300,000 years ago, a new genetic model suggests. The unknown population contributed 20% of our DNA and may have boosted humans' brain function.".

DAVID: sort of clarifies dhw's question about our origin.

dhw: Not really. There are no details given. Were they a group of African tree-dwellers who descended to the savannah? Or you yourself might ask if they existed in several groups, to each member of which your God personally gave new legs, a new pelvis and a new brain before they descended.

DAVID: We are stuck with we came from Erectus, who came from someone who came from Lucy,etc.

Agreed. That is why none of the articles you have presented can in any way disprove the perfectly logical savannah theory regarding the origin of sapiens. You have even supported it yourself with the above theory concerning God’s leg, pelvis and brain operations.