Different in degree or kind: big brain evolution (Introduction)

by dhw, Monday, December 19, 2016, 13:03 (2686 days ago) @ David Turell

dhw: I suggested that – along the lines of Sheldrake’s morphic resonance – the energy, and hence the information, produced by the brain could last indefinitely, but this did not settle the issue whether that energy and information could be added to once its producer had ceased to function (i.e. whether there might be such a thing as the soul that allows us to live on as an individual identity after death).

DAVID: I think the soul is added to universal consciousness, but I think its information is fixed, nothing added.

Although this is a side issue in the present context, it’s important in its own right. If nothing is added, i.e. no new information, there is no individual afterlife. That may well be true, but it goes against all the accounts of NDE patients, who remain themselves and undergo new experiences.

dhw: Does intelligence change the body, or do changes in the body engender intelligence? The following quote may offer us a clue:
“It’s a mistake to think we can explain brain size with just one or two mutations. I think that is dead wrong. We have probably acquired many little changes that are in some ways coopting the developmental rules.”
Wray concurs: “It wasn’t just a couple mutations and — bam! — you get a bigger brain. As we learn more about the changes between human and chimp brains, we realize there will be lots and lots of genes involved, each contributing a piece to that. The door is now open to get in there and really start understanding. The brain is modified in so many subtle and nonobvious ways.”

DAVID: This does not accept the gaps that imply an enormous number of genetic changes between H. habilis and H. erectus and H. sapiens. First big brain ,second more intelligence as that brain is used.

The researchers say lots and lots of genes are involved, and each contributes “a piece”. I think that allows for any number of changes. As regards the brain, what I am trying to describe is a feedback process, as detailed below. (See “In brief”…)

dhw: Once the spark is lit, the next step is the effect of thought on matter: the brain responds to exercise; new activities demand new connections between brain and muscles, and new forms of communication between members of the group. One thing leads to another in a perfectly logical chain of developments.
DAVID: You make it sound simple but the brain had to be given the ability of plasticity. What if the brain didn't have that? I think God supplied that attribute.

Plasticity had to be given to cells from the very beginning of life, or evolution could never have taken place. They only lose their plasticity when they are assigned a particular fixed role (though stem cells remain plastic). No, it’s not simple. It’s miraculously complex, and as I have made clear at the end, my hypothesis leaves plenty of room for your God!

dhw: In brief, the brain engenders thought, and the extraordinary levels of consciousness that distinguish us from our fellow animals are the result of new needs engendering new thoughts which, in turn, engender physiological adaptations, including the expansion of the brain.
DAVID: I really doubt that thoughts create new physiology. I can think I want to exercise and enlarge muscles, increase heart strength, but noting more happens.

What I am proposing is not “new physiology” – it is development of existing physiology. The long line of our animal ancestors all had brains. The human brain was not new. It was enlarged. Vocal tracts and thumbs also existed. On this thread we are tracing the origin of humans, not of organs.

dhw: What we do not know is the spark that lit the fuse for this chain reaction. That, however, would be the only instance of “serendipity” – productive good luck, in contrast to the bad luck that has left 99% of species extinct. Variability within species is enough to explain why some groups of primates remained the same while others advanced. And there is no exclusion of the God theory, since this is a very late chapter in life’s history, and deals only with the origin of humans, and not with that of life and consciousness.
DAVID: God lit the spark and guided the development. note, only one group of primates advanced in shotgun style, those that led to H. sapiens.

You yourself have drawn attention to the fact that there were several groups, and I don’t know what you mean by “shotgun style”. Other groups, including the Neanderthals, eventually became extinct, but I don’t know what point you are trying to make here. Mine is that once the spark of enhanced awareness was lit, it caused a chain reaction which can explain not only the expansion of the brain but also other physiological changes which in turn contributed to the enhancement of our intelligence. The more you can do, the more you learn, and the more you learn, the more you want to do. That means making more tools or adapting existing ones.