[Squawk 8888]

It not only required changes in size of the brain but significant changes in reproductive capabilities to accomodate larger brain size.

Yep. That's why most species are born with the ability to survive alone, or at least to be able to function independently within a year of birth. For humans, the gestation lasts for a few years after birth, because no woman would survive giving birth to a child with a fully developed brain.

[Erasmus]

Indeed. It was a collision between the exploding cranium size and the shrinking birth canal due to the adaptation to bipedalism that causes such difficulty for human mothers.

It's as if Mother Nature allowed the two trends to continue up to the practical limit. And she didn't care how much pain a human mom went through, just so long as not too many delivering moms and their babies would die.

Momma Nature's kind of an uncaring bitch.

≤}B^)