Big brain evolution: brain size and intelligence (Evolution)

by dhw, Sunday, April 22, 2018, 13:45 (2405 days ago) @ David Turell

DAVID: Cro-Magnons show advanced thought shrinks a brain, not the opposite effect.

dhw: Cro-Magnons show that over the last x thousand years, the sapiens’ brain has shrunk. You have just agreed that it is material complexification (not immaterial thought) that shrinks the brain, and complexification, as modern science has demonstrated, is caused by IMPLEMENTATION of thought.

DAVID: Another misinterpretation of my thought. Our brain shrunk exactly because of new complex intensive immaterial thought, which drove the complexification to cause shrinkage. You cannot separate the two.

There are three steps and not two. Immaterial complex intensive thought by the dualist’s “soul” is the first step. Material implementation by material complexification of the brain is the second step, the efficiency of which is the direct cause of the third step: material shrinkage. We can observe how the implementation of individual concepts complexifies the brain, but shrinkage has occurred over thousands of years, and so we can only offer a general explanation.The 150 cc shrinkage must have been accumulative, as efficient complexification made some cells and connections redundant.

Dhw: 1 Facts: a) pre-sapiens’ brain expanded; b) sapiens’ brain has shrunk; c) implementation of thought causes brain changes (complexification and limited expansion) in sapiens; d) sapiens’ thought has made major advances during the last x thousand years.
DAVID: Not 'limited expansion' but 150cc shrinkage.

“Limited expansion” refers to the examples of taxi drivers and musicians, where sections of the brain expand owing to special usage – but the expansion remains within the limits of the skull.

dhw: 2 You agree a) that in dualism the “soul” (software) does the thinking and interacts with the brain/body (hardware), which does the implementing; b) complexification has caused shrinkage in sapiens.
DAVID: Because of intensive new thought.

Because of efficient complexification during the implementation of intensive new thought. See above.

dhw: 3 dhw’s dualistic hypothesis: a) pre-sapiens “soul” thinks up new concept; implementation of concept requires additional brain cells and connections. Brain expands; b) brain/skull reach maximum practical size in sapiens; “soul’s” thoughts now implemented by complexification and limited expansion of particular sections; c) process of complexification so efficient that sapiens’ brain no longer needs certain cells and connections, and shrinks.

DAVID: Your theory is some not very complex thought, as compared to ours, in early hominins explodes the brain and with it the skull to larger size. Is this an explanation for speciation?

Why do you insist on comparing degrees of complexity? The advance from bare hands to manufactured weapons and tools was a huge advance in its day, and as you once acknowledged, involved highly complex thinking and physical activity. Use the word “explode” if you like: your theory then is that your God “exploded” the brain, and only then could pre-sapiens’ soul think the complex thoughts enabling him to manufacture weapons/tools. This directly contradicts your dualistic belief that thoughts derive from the soul and not the brain! And yes, if your God speciates by exploding the brain before it can think new thoughts, then the brain exploding through implementation of new thoughts also explains speciation.

dhw" 4 All advances in thought must begin with individuals. Every stage in pre-sapiens human evolution continued for hundreds of thousands of years without significant advances until someone came up with new ideas which required brain change (expansion). Sapiens continued for hundreds of thousands of years until someone came up with new ideas which required brain change (see 3 b and c). The pattern is consistent.

DAVID: Consistent only in your thinking. Pre-sapiens dealt with survival skills, not complex thought. They were little different than the wild animals we see today.

See above for “complex thought”.

DAVID: The larger brains that appeared with each new advanced species produced more advanced artifacts. Artifacts require planning thought that only a bigger brain could supply through its s/s/c. And then implement the production of them. This pattern is consistent with history.

“…thought that only a bigger brain could supply through its s/s/c” is one of your now typical obfuscations. In dualism the brain does not supply thought through anything! You have agreed over and over again that the s/s/c is the supplier of thought. Planning is thought. The material brain implements the immaterial thoughts/plans of the immaterial s/s/c by producing the material object. Concept (thought/plan) precedes implementation of concept. Yes, the larger brains produced the artefacts, but it was the s/s/c that planned them, and we know that brains change through implementation of ideas – they do not change in anticipation of new ideas.