It appears that the human type came about on purpose. Firstly evolution fashioned the large brain of the hominids and then it provided the keys to unlock the power in this brain. Humans have four very notable physical traits. We are naked, physically weak, our females have no season of heat and we have advanced vocal abilities. All these physical traits conspired to prod humankind into an odyssey of self discovery.
History testifies to the gradual realization by humanity of the power of intellectual thought.
Our weapon of choice is our mind and not some deadly claw or fang. The human mind that has created great civilizations over the world is comparable to the human mind born into the stone age. However, it is only now that we humans are getting up to speed with this mind. Our intellectual power was quite out of place in the stone age. Thus we have a picture that evolution deliberately brought about human intelligence.