In this study, I will approach morality from a naturalistic perspective and defend that morality is a product of evolutionary processes shared by both human and non-human animals rather than that of human culture. My naturalistic approach is based on simpler components instead of high-level cognitive capabilities such as cognition. Rationality, judgment, and free will are indeed presented as necessary for morality in classical definitions of morality. However, I will put forward that the roots of morality can be understood as the biological disposition in the evolutionary process. Moreover, in this paper, I will propose that morality is not a phenomenon that ought to be restricted to humans. I think morality is not a phenomenon that is exclusively human; rather, morality can be expanded to non-human animals. To defend this claim, I will indicate that morality has a natural content and that this content does not have a structure that can only be justified on a rational basis, but that this normative structure can be established through biological/evolutionary mechanisms and can be explained in this way.