Although many explanations exist for the origin of life – mostly from traditional religions, the most robust scientific explanation is the one driven by entropy. A singular direction of time coupled with unambiguously increasing entropy in the universe, point to life as a mechanism that accelerates entropy. Those wondering why a group of complex chemicals will get together and act in unnatural ways, could consider the existence of a simple objective function as the maximization of entropy from available means. In other words, life is the most efficient way to accelerate entropy given a chemical condition.
Evolution, then, could be explained in the same vein. If more complex life forms increase entropy at faster rates, then, there should be a natural push toward the creation of such life. Simpler life, should lead to more complex ones and this is fundamental to evolution. However, from a system perspective, if such a transformation leads to aggregate loss in entropy creation – either due to volumetric loss of simpler life or constraints placed on them by evolving complex ones, then, evolution can lead to suboptimal performance. Since the physics of entropy cannot be refuted, it has to be that complex life is fully capable of compensating for any loss of entropy creation from entities they evolved from. The evolution of the brain, a highly inefficient organ, in mammals, certainly fits the bill.
Evolution, may be better explained by physics, as a process that accelerates the entropy of the universe