New Miscellany2: savannah, Cambrian, brain, origins (General)

by David Turell , Sunday, March 30, 2025, 18:13 (4 days ago) @ dhw

The savannah theory

DAVID: With hominins living everywhere does not support the savannah theory of homo evolution.

dhw: Hominins lived everywhere after they had evolved from hominids. The question is why our direct ancestors descended from the trees, and that is not answered by telling us that after they had descended from the trees, they spread far and wide.

The savannah theory said without trees hominids had to be bipedal, i.e., the new climate forced it. How does that explain bipedalism in forests, as shown?

The Cambrian

DAVID: It is always my point God designed the animals to handle the new conditions.

dhw: Your opinions vary day by day. You regarded this article as providing a logical explanation for the Cambrian.

DAVID: Yes, a natural explanation.

dhw: With which you agreed. (“For once a logical set of reasons for developing early life forms”). So why did you say “I never agreed with them!!!”?

DAVID: These are the reasons for God's designs!

dhw: So you agree that life forms respond to changing conditions, but you disagree because it is your God who responds to changing conditions. Although if I remember rightly, your God preprogrammed all the adaptations 3.8 billion years ago, or looked into his crystal ball and operated beforehand on those creatures he wanted to rescue.

God, as designer, handled all new environments.

The brain’s cleaning fluid

dhw: Are you saying that the human brain did not evolve from earlier mammalian brains?

DAVID: It did, through God's design modifications.

dhw: But I thought you thought he knew from the start exactly what he wanted. You make him sound just like a human scientist or inventor, experimenting, adjusting, jettisoning (let’s not forget the 99.9%), operating….And yet for some reason, you hate the very idea of humans reflecting their creator through their own processes of creation.

DAVID: Evolution is a process to a goal God had from the beginning.

dhw: So either he was ridiculously messy, cumbersome and inefficient (your proposal), or just like humans, he conducted numerous experiments before he was able to produce what he wanted. You prefer the former explanation.

Yes.

The human brain

1) DAVID: God made our big brain anticipating future needs.
And:
2)DAVID: The original brain had the capacity to be today's brain with no size change.

dhw: Number 2) is correct. The big brain – as with every earlier expansion – added new cells to cope with new requirements (e.g. perhaps a change of environment, such as trees to savannah), and since then all new requirements have been met by complexification in an ongoing process. There were no complexifications made in anticipation of not yet existing requirements.

Agree.

Extreme extremophiles: from dormancy to living

DAVID:: these diatoms are very simple forms that can assume dormancy. It just shows how tough living cells can be. The hibernating bear is a different form of this.

dhw: Yes, they are tough, and each example illustrates the versatility of cell/cell communities as they find different ways to cope with different environments. Some of us would suggest that these ingenious forms of adaptability are evidence of autonomous intelligence (perhaps God-given) rather than evidence of direct design by a God whose sole purpose was to design humans plus food.

DAVID: That is to your view.

dhw: I am not alone, as you well know. And as we have seen, you remain at a complete loss as to why your God should have created so many different organisms and modes of survival if his only purpose was us and our food. But you continue to champion your belief in an all-powerful, highly inefficient God.

I have never known why God chose to evolve us.