Big brain evolution: comparing chimp and brain organoids (Evolution)

by David Turell , Wednesday, February 13, 2019, 14:50 (2108 days ago) @ dhw

dhw: You are talking as if there was a sudden leap from chimp to H. sapiens. What both you and the article have failed to acknowledge is the many stages of evolution between chimp brain and H. sapiens brain. And yet you believe in common descent. Once more, then, we have to go back to the only explanations you will accept: 1) either your God provided the very first cells with a programme to change the brains (and female pelvises) of a group of apes and force them out of the trees for no particular reason, and then at intervals of millions of years more programmes were automatically switched on to change the brains of their descendants, or 2) your God picked out a group, and then later groups, and popped in to perform all the necessary operations himself on all the individuals in those groups (= dabbled). And all this happened because, even though the only brain he wanted right from the start was that of H. sapiens, he either couldn’t or didn’t want to design it until he’d specially designed all the other brains plus 3.5 billion years’ worth of other life forms, lifestyles and natural wonders. But this apparently makes sense to you.

DAVID: Fortunately or unfortunately there are just a few hominin stages from chimp to sapiens, a jump of 400cc to 1,200+cc, thus making each stage a large jump. Those jumps had to be designed. I don't know why the earliest hominins partially and then completely left the trees as Lucy and other very early specimens showed both tree dwelling and terrestrial characteristics. And you still don't accept that the God you don't accept used a stepwise evolutionary method to achieve His goals. God should be allowed to chose the method He wants, even if He doesn't suit your human standards for Him.

dhw: Of course I accept that if God exists, he used evolution to achieve his goals! But you persist in your fixed belief that there was only one goal from the very beginning: to produce the brain of H. sapiens! You have agreed that the various alternatives I have proposed re goals and evolutionary methods are possible, and we signed a peace treaty at 15.37 on Friday 8 February under “God and evolution”, but now back you go again to your rigid framework as bolded above.

Let me offer you a possible solution to the mystery of Lucy and Co. Maybe in a particular location, tree-dwelling became impractical, and so a particular group of tree-dwellers had to adjust to life on the ground. And life on the ground required or led to new skills, and new skills required changes to the brain which went beyond the brain’s existing capacity. (We know that certain areas of the modern brain expand according to usage, as in the case of taxi-drivers and musicians.) Why do you regard that as less feasible than your God performing brain and pelvis operations on a particular group of tree-dwellers and then forcing them to leave the trees for no apparent reason?

The final bolded statement of yours is our difference. God had perfectly good reasons for creating the Lucy-like early hominins, because He had future plans and the purpose of creating H. sapiens over many years of stepwise evolution, at a point when each step was ready to begin.