This subject has been answered many times. “Morality” evolved because it has an obvious and powerful survival advantage. Groups that co-operate, share resources and protect each other from harm will obviously have a greater chance of survival than groups that murder and fight one another and steal each other’s recourses. Therefore individuals that evolved a psychology that favored altruistic behaviours like sharing and co-operation survived more than selfish “loner” individuals. Although humans have a much more complex “moral” system than other animals, the concept of altruism and simple morality is evident in many species. Altruism is common in the animal kingdom because it’s evolutionary beneficial to many species. Especially social animals. https://plato.stanford.edu/entries/altruism-biological/ [quote]Altruistic behaviour is common throughout the animal kingdom, particularly in species with complex social structures. For example, vampire bats regularly regurgitate blood and donate it to other members of their group who have failed to feed that night, ensuring they do not starve. In numerous bird species, a breeding pair receives help in raising its young from other ‘helper’ birds, who protect the nest from predators and help to feed the fledglings. Vervet monkeys give alarm calls to warn fellow monkeys of the presence of predators, even though in doing so they attract attention to themselves, increasing their personal chance of being attacked. In social insect colonies (ants, wasps, bees and termites), sterile workers devote their whole lives to caring for the queen, constructing and protecting the nest, foraging for food, and tending the larvae. Such behaviour is maximally altruistic: sterile workers obviously do not leave any offspring of their own—so have personal fitness of zero—but their actions greatly assist the reproductive efforts of the queen.[/quote] Morality is what we call a set of behaviors and social norms that encourage social cohesion. While “morality” may seem counterintuitive to the concept of “survival of the fittest” it’s not really. Yes evolution is about survival of the individual. But sometimes the best way for an individual to survive is through altruistic and non-selfish cooperation with others. The success and survival of the whole group ensures the success and survival of the individual. This is why highly social species have evolved so many times. There is safety in the herd and “morals” are behaviors that encourage herd cohesion. Here’s a whole article about the subject: https://www.frontiersin.org/articles/10.3389/fsoc.2018.00017/full I would also recommend reading “The Selfish Gene” by Richard Dawkins that also covers this subject.