The evolution of morality refers to the emergence of human moral behavior over the course of human evolution. Morality can be defined as a system of ideas about right and wrong conduct. In everyday life, morality is typically associated with human behavior and not much thought is given to the social conducts of other creatures. The emerging fields of evolutionary biology and in particular sociobiology have argued that, though human social behaviors are complex, the precursors of human morality can be traced to the behaviors of many other social animals. Sociobiological explanations of human behavior are still controversial. The traditional view of social scientists has been that morality is a construct, and is thus culturally relative, although others argue that there is a science of morality.
Though animals may not possess moral behavior, all social animals have had to modify or restrain their behaviors for group living to be worthwhile. Typical examples of behavioral modification can be found in the societies of ants, bees and termites. Ant colonies may possess millions of individuals. E. O. Wilson argues that the single most important factor that leads to the success of ant colonies is the existence of a sterile worker caste. This caste of females are subservient to the needs of their mother, the queen, and in so doing, have given up their own reproduction in order to raise brothers and sisters. The existence of sterile castes among these social insects significantly restricts the competition for mating and in the process fosters cooperation within a colony. Cooperation among ants is vital, because a solitary ant has an improbable chance of long-term survival and reproduction. However, as part of a group, colonies can thrive for decades. As a consequence, ants are one of the most successful families of species on the planet, accounting for a biomass that rivals that of the human species.