(April 28, 2015 at 12:08 pm)robvalue Wrote: I wonder if mortality rates have got lower though, bad as they are now. If a woman dies, she can't have any more kids... so I would have thought the longer a woman can have kids before dying, the more her genes would get passed on.
That's based on literally nothing, but it makes sense to my addled brain.
Obviously I'm talking long term here.
The thing is, a big brain helps with the survival of the offspring, and that is the cause of the big head, which is one of the things that makes childbirth more problematic. As things are, humans are born less mature than many other animals, which is necessary because their heads would be too big if they were comparably mature to many other animals at birth.
So, you are right, that a mother who can give birth to more children is likely to be evolutionarily advantageous, if all else were equal. But a big brain improves chances of survival of the offspring, which is essential for the survival of that line. Or in other words, all else isn't equal.
"A wise man ... proportions his belief to the evidence."
— David Hume, An Enquiry Concerning Human Understanding, Section X, Part I.
