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

by dhw, Sunday, December 18, 2016, 13:52 (2688 days ago) @ David Turell

PART ONE

DAVID: This article covers the changes required in metabolism among other issues:
https://www.quantamagazine.org/20151110-evolution-of-big-brains/?utm_source=Quanta+Maga...

QUOTE: "No matter how large the human brain grew, or how much energy we lavished upon it, it would have been useless without the right body. Three particularly crucial adaptations worked in tandem with our burgeoning brain to dramatically increase our overall intelligence: bipedalism, which freed up our hands for tool making, fire building and hunting; manual dexterity surpassing that of any other animal; and a vocal tract that allowed us to speak and sing. Human intelligence, then, cannot be traced to a single organ, no matter how large; it emerged from a serendipitous confluence of adaptations throughout the body. Despite our ongoing obsession with the size of our noggins, the fact is that our intelligence has always been so much bigger than our brain."

Thank you again for this fascinating article. It may be that the author is unaware of the research suggesting that some monkeys already have vocal tracts that are flexible enough to make human sounds, and it is the brain that holds them back – but it makes no difference to the overall argument or, ultimately, to the mystery of our intelligence. The “serendipitous confluence of adaptations” is an important phrase. You, David, will assume that all these adaptations were engineered by your God, so I’m surprised you didn’t pounce on the word “serendipitous”! My own focus, though, is on the question to what extent these adaptations (including the brain) were the cause of intelligence or the result of intelligence

For dualists who claim that the brain is the receiver of consciousness and not the producer, the increase in the size of the brain would come from the need to process more and more information. For materialists, the increase would produce a corresponding increase in consciousness and intelligence. Dualism puts intelligence first and receiver (brain) second; materialism reverses the process. In my attempt to reconcile the two approaches (Human consciousness: Penrose: soul survives! 8 November at 12.16), 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).

The related question raised by this article is how and why the brain and our consciousness and intelligence increased on such a massive scale, and it really comes back to how evolution works. 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.” (Contd. in Part Two)