Clever Corvids: the cortical equivalent in many birds (Introduction)

by David Turell , Saturday, September 26, 2020, 00:08 (1520 days ago) @ dhw

dhw: Thank you for yet another stimulating article. It touches on quite a few of our issues.

QUOTE: So far, it appears that the more neurons there are in the pallium as a whole, regardless of pallial, brain, or body size, the more cognitive capacity is exhibited by the animal. (David’s bold)

dhw: This is a major factor in the debate between materialism and dualism. Does consciousness/ intelligence/cognitive capacity arise out of the neurons, or do the neurons multiply in accordance with the demands of a conscious intelligence? (NB that does not mean that our fellow animals have the same DEGREE of consciousness/intelligence as ourselves.) Were ancient corvids as intelligent as modern corvids, and did they have the same number of neurons? No way of knowing. What researchers could find out, though, would be whether corvid brains, just like human brains, complexify in response to new requirements (e.g. when they solve specific problems).

Bold is unknown as yet, but their current brain complexity allows what they can do. Which translates into my view that what level of mental complexity occurs is based on the number of neurons and their networks complex design. One can only work with what is given. We work with a brain given to us at least 315,000 years ago and its complexity allowed what has subsequently happened.

DAVID: We knew birds were smart, and now we know why. Part of me is very interested in the bolded comment at the end. Hominins and homos were in small population numbers before we advanced 50,000 years ago and began to build a large population. This fits Gould's concept of small isolated populations causing rapid or large evolutionary advances.

dhw: This was the point I made about the Cape Verde people developing immunity to malaria. We seem to be in agreement, and this has major implications for the whole of evolution. You had asked why humans evolved while apes remained the same, and I responded that conditions may have forced local groups to descend from the trees while elsewhere the apes lived happy ever after.

But note the conflict with Gould's thinking I mentioned in the Neanderthal Y entry today:

"Neanderthals had smaller populations than moderns, and small populations tend to accumulate deleterious mutations, especially on the X and Y sex chromosomes".

DAVID: What is weird is that a small population is like to have less mutations than a large population, but large brains appeared anyway. That supports the concept of a driving force like God.

dhw: What is weird is that according to you, the driving force behind corvid intelligence and that of every other form of intelligence was your God's one and only desire to design sapiens intelligence. They were all "part of the goal of evolving humans". I would suggest that in all instances, the driving force was the urge of the cell communities to improve their chances of survival by using the intelligence your God may have provided them with from the beginning.

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My same disagreement. Apes survived just fine without morphing into our big brains.

DAVID: The other point is it is the volume of neurons that make a difference. Size, by itself, is not a major guide to brain capacity as the first bold shows.

dhw: Just to link this to our "brain expansion" thread: there is a limit to the number of cells each skull can contain. A corvid presumably wouldn’t be able to fly if its head doubled in size, and so I have proposed that the human skull eventually stopped expanding because further expansion would have created problems for the rest of the anatomy. For other implications concerning volume, see my first comment above.

Based on corvid brain size and what they can do, as I think with humans, a slight skull enlargement is anatomically possible but not necessary because the current brains work so well. Your harping on skull size is a side issue. Neanderthal skulls were much bigger and our earlier brains were also larger. So what! Our brains are at final size since IMHO speciation is over as is major evolution. All that is left are minor adaptations