Obviously the development of a large brain was an exceptionally good adaptation culminating in the modern human brain.
Freethinker, I think you have used a word that separates the discussion.I think Freethinker nailed it.
ADAPTATION. I've seen the word mutation misused many times on many boards.
There is so much misunderstanding of the difference of these words and how they fit into the Darwinian theory, that most people are seemingly confused.
A mutation in ones genetic makeup is akin to hurling a large monkey wrench into an automobile engine and expecting it to run better.

You're right on F/T. I'll keep reading your posts.