You don't have to be Religious to have Morals.
So it's not hard for me to believe that now Science might have found an evolutionary benefit to morals. It's so common sense, and I've always seen the bible reinforces our morals, instead of handing them to us.
So much of the "law" in the bible is really etiquette that had a place & time where it was appropriate. Pigs aren't really great desert creatures, so it kinda seems natural that people in the Middle East would find them repulsive to eat just as many Americans find insects repulsive to eat. If the bible was written today, it may very well include public-restroom etiquette.
But the golden rule, "love one another" is found everywhere.
And on a side tangent, this article states that "many evolutionary biologists frown on the idea of group selection," based on that only an individual can pass on genes. I have no problem with the idea of "group selection" since I thought evolution was not just the survival of the fittest, but the death of the least fit.
Considering that, I feel one obvious argument for group-selection of moral behavior has been overlooked in this case: punishment & weeding out. Being ostracized from a community based on inappropriate actions definitely reduce one's chance of reproducing. And "groups" are actually often "family," with similar genetic structure.
People more naturally do contribute altruistically to people related to them, but two unrelated grandparents would be encouraged to contribute to each other for the sake of their ability to take care of their mutual grandchildren. And in turn it is of a benefit to take care of the elderly because of the information they can pass down (Memes), which can benefit every one's survival. If you're nice to your neighbor, he might show you how he made that nifty stick that gets the tasty termites at the bottom of the mound. Give a man a boat, and he will teach you how to fish.
Being altruistic is most beneficial to an individual if everyone in a group is altruistic. It's a tit-for-tat relationship, and this allows specialization. If one member of a group is really good at getting berries from the top trees, and another is really good at sniffing out mushrooms, and they get along socially, they can share and both benefit from the additional nutritional value.
Our society has blossomed into an extreme of this example. We go to college to study to be engineers, fire fighters, nurses, teachers, tailors, etc. Almost none of us could live on our own, and we all live better if we share in the wealth produced by specialization.