The difference in muscle power versus density between Homo sapiens & other mammals is, in my opinion, the first premise upon which Darwin should be questioned. Granted, the diversion of energy from physic to intellect would have an impact however, the micro-evolutions he observed & subsequently translated into a theory of an "origin of species", in my opinion, leaves much to be desired in explaining how a small line of creatures that sometimes show some aptitude at tool usage & usually give up attempts at interpersonal communication in fits of rage became a new species of creatures that sometimes show some aptitude at tool usage & usually give up attempts at interpersonal communication in fits of rage. I'm not saying that it's impossible. I'm suggesting that the time line feels weird. And the result feels like an answer looking for a question. Is it plausible? Sure. Just as plausible as a butterfly causing a hurricane. Should we present either as fact without question? I shouldn't think so.