Will Ayn Rand's Conjectures on Evolution Prove Right?
Nevertheless, whether or not Rand’s conjectures are proven right one day, we should seek a deeper comprehension of how self-reflective consciousness arose in human history, how it arises in children, and how such mental processes give rise to free will, morality, neuroplasticity, and self-actualization.
The Dawn of Consciousness is the easier book to digest and is also much more recent. See the essay for the hyperlink.
Meanwhile, there is a Gulch member who is a fan of JulianJanes, I have looked at the book and am still ambivalent.
The question of consciousness has been discussed by Richard Dawkins who says (from my memory), ~it is the big question, we do not know where to look for explanation, or what kind of questions to ask~ and it seems to relate not just to size of brain but number of interconnections.