Should ethics begin with facts about evolution, including altruism?

The ethical egoism advocated by Ayn Rand doesn't seem to incorporate genetics or evolution. Having evolved in tribal and family groups, we are creatures tuned to group behavior more than to individual behavior. Altruism wasn't made up by religion. In a tribe, helping those around you helps you survive too. Helping your kin helps your genes survive. The fact is that feeling good when you help others is built into the core of being human. The fact is that much status seeking and other seemingly irrational actions are techniques to ensure the propagation of our genes. Objectivism starts with "A is A." But, if reality is most important, shouldn't people base their ethics on the facts about humans as they actually are -- altruism and all?