I touched on this subject almost a year ago when an article in the New York Times noted that morality could be explained simply by evolution. At the time, I noted:
"Can we explain our morality from a strictly biological perspective? Dr. Francis Collins -- a theistic evolutionist -- dismisses the argument that humans obtained their moral reasoning from the evolutionary process. For one, evolution does not explain why humans commit acts of kindness unknown to anyone. Secondly, why do we risk our safety to help people outside of our group (as did Mother Teresa and Oskar Schindler)? The apparent existence of right and wrong, he believes, is a persuasive argument for the existence of a god. Many others who wrote before Collins (including C.S Lewis) also hold such beliefs."