Nature as humans have discovered is pretty consistent. There is energy and matter and the effects of energy are consistent and the condition of matter varies IAC with it's exposure to energy. Since our nature actually arises to our interactions with matter and energy evolution is pretty consistent in how we interact with them. The nervous system has been evolving for at least 500 million years across species.
Over time our relations with matter and energy change IAC local conditions ergo our interactions are driven this or that way. These are but very minor except with respect to particular species which may rise and fall. Occasionally major changes in those conditions change at which time opening of niches permits explosive realization of various genetic tendencies without changing the rate at which individual genetic variation occurs (mostly through genetic structural weaknesses and mutation).