Evolution and humans: big brain size or use (Evolution)

by dhw, Thursday, June 01, 2017, 11:39 (2730 days ago) @ David Turell

As you keep ignoring your own beliefs, I will summarize the argument so far, and then deal with the objections you keep raising.
According to you, body and mind are separate, and the mind is a piece of God’s consciousness which does all our thinking and which returns to God when the body dies, retaining its individual identity. This means that it is consciousness/the self that does the thinking and the brain is the receiver. We know that the brain changes its structure (densifying) in order to accommodate thought, and not the other way round. However, despite all of this, you believe that the enlargement of the receiver led to the complexification of thought, instead of complexified thought requiring and therefore producing the enlargement. I find this illogical in the context of the above beliefs.

DAVID: This is entirely backward. Compare brain size to known activity from archaeological findings. Human activities were simplistic until 10,000 years ago, but advanced after each enlargement.

We have no idea what our ancestors were thinking, because thought processes leave no archaeological traces, but we do have some products of their thought. What we know, for instance, is that our larger brained ancestors made tools. How do you know that the tools they used were not the products of thoughts that demanded new activities which in turn enlarged the brain? In other words, the receiver expanded to accommodate the demands of the generator. You make great play of the fact that the homo sapiens brain is approx. 200,000 years old, but there wasn’t much progress till 45,000 years ago (language) or 10,000 years ago with early civilizations. What does that prove? The apparent lack of progress is not explained by the theory that the receiver must be big before we can think big thoughts. Neither theory explains the apparent sluggishness. But yes, the receiver had reached its then optimum size, so instead of expanding (and bursting the balloon), it densified – a process we know involves thought (i.e. use of the brain) changing the brain, not the brain changing thought. Current shrinkage perhaps indicates the sheer efficiency of densifying – the extra volume is no longer required. I don’t know why you think shrinkage means brain size must precede enhanced consciousness.

Your other objection is that enlargement proceeded by saltations. We have agreed that this applies to many innovations throughout evolution, and nobody has yet explained them. Your hypothesis is a divine 3.8-billion-year programme or direct dabbling, and mine is a perhaps God-given intelligence which enables cell communities to cooperate in forming new structures. There is no proof for any of these hypotheses.