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

by dhw, Monday, March 31, 2025, 10:37 (3 days ago) @ David Turell

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.

DAVID: 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?

You should ask yourself the same question: if your God operated on tree-dwellers’ legs and pelvises and told them to descend from the trees, how does that explain bipedalism in forests? We can only theorize. Perhaps the answer is that when the first hominids began to explore further and further afield, some would have reached forests and would have interbred with the tree-dwellers. Your explanation?

The Cambrian

dhw: 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.

DAVID: God, as designer, handled all new environments.

You have always vacillated over this – especially when it comes to the local (as opposed to global) changes which would have led to so many new species. But this reinforces the illogicality of your theory. He started out with the sole intention of creating us, but deliberately kept designing new organisms in preparation for the environmental changes he deliberately created, although this meant that he was deliberately creating 99.9 out of 100 species which he knew he would have to cull because they had no connection with the only species he actually wanted to create. Divine lunacy. Especially since you believe that our line of evolution actually began “de novo” in the Cambrian, when at last he invented an environment that was suitable for us and our ancestors!

DAVID: ( under “the brain’s cleaning fluid”): 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.

DAVID: Yes.

Even I, an agnostic, have more respect for your hypothetical God than you do!

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.

DAVID: Agree.

Although you think he made our big brains in anticipation of future needs, you agree that our big brain was not made in anticipation of future needs, and I suppose that tomorrow you will tell me you agreed because NOT in anticipation actually means in anticipation.

Extreme extremophiles: from dormancy to living

dhw: 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.

DAVID: I have never known why God chose to evolve us.

You have never known why he chose to design 99.9 out of 100 species irrelevant to his purpose, but you simply choose to ridicule him instead of questioning your illogical theories concerning his purpose and method of achieving that purpose. Why does it never occur to you that your all-powerful God might simply have created what he wanted to create, instead of being the blunderer you make him out to be?