Intelligence is a product of the natural, as we can show by the dimunition of intelligence through brain damage, or through the deprivation of oxygen. In other words, there is nothing supernatural about your ability to think, reason, recognize self, etc.
A related question which evolutionists (or perhaps we should say materialists) need to answer is how come with the same genetic makeup, with the same brain material, intelligence, not just among humans, but between humans and different species differ so much?