Evolutionists use a fancy hall of mirrors when talking about this stuff. The goal of an organism is to pass along its particular genome. This is why we protect progeny and siblings--they share lots of genes with us so we help preserve them to protect the fragments of the gene sequences that we hold in common. So to extend it further, we perform altruistic acts because of misappropriated behavior -- we have this inclination to help related people but apply it to unrelated people. Even that may help in that the unrelated people for whom you did service may be less inclined to do interfere with progeny of the helpful group. And thus we proceed from family to clan, to tribe, and nation. It builds to sacrifice in mechanized war.