Recognizing the built-in, universal nature of morality doesn't explain all of ethics. You aren't like anyone who has ever existed, or exists today or will exist tomorrow. This is true for two reasons. On the biological level, there is a part that belongs to you and you alone. While you share most of your DNA with chimps and even more with humans and still more with relatives, there is a residue that is yours alone.
Scientists at the Netherlands Institute of Ecology find that birds within species behave in consistently different ways. Some birds are shy, while others are bold, traits that remain over a lifetime. Breeding experiments in the wild reveal the genetic basis of the difference. Other scientists have found personality differences in squid, chimps, and hyenas and are looking for the genes that may explain them.
The presence of personality in humans is obvious. What is not so obvious is whether there is a genetic component to it. The guess is that there is and it helps to explain, in part, why our tastes and temperaments differ even from our closest relatives.
Michael Gazzaniga, of Dartmouth's Center of Neuroscience, concludes from his analysis of his readings of the many studies of neuroscience and psychology that "the interaction between genes and the environment makes us what we are. Genes are the scaffolding, but the fine detail is tuned by interactions with the environment . . ."
Since all societies face common problems such as providing food and shelter, arranging for defense against predators, ensuring a modicum of health, and raising children, it isn’t surprising that the moral sense that Darwin intuited is found in the scaffolding of our genes. The different moral formulations found throughout the world result from the interaction of the genes that are uniquely your own, those you share with all other humans, and the challenges for human survival presented by environment.
Morality, then, is universal, in the sense that the structures and regulations necessary for regulating human behavior for the sake of survival is found in all societies, but in practice morality is relative to individuals and the social situations human find themselves in and must navigate in order to go on living.