Many atheists seem to think that evolutionary biology can answer moral questions and, in this way, defeat the theists' claims that moral goodness requires God.
Yet, their arguments hit very wide of the target. It would not be unfair to say that they do nit understand the question.
For example, one claim is that evolutionary forces can select for altruistic behavior - it can code for self-sacrifice. One specific form of altruism with an apparent evolutionary explanation us kin-selection, such as the sacrifice of a patent for a child. Organisms with this trait have more children which grow to adulthood and have yet another generation of children.
So, evolution can provide at least a partial explanation for altruism.
But why us altruism good?
This is the question that I want the evolutionary biologist to answer: What makes altruism a virtue?
How can altruism itself be a virtue without a God to give it that quality?
The objection states that, without God, anything can be a virtue. For example, a person who does not believe in God might come to the opinion that selfishness us a virtue. A person is free to adopt the attitude that the fact that we evolved to exhibit certain forms of altruism – assuming it is a fact - means that we have evolved certain mental defects and vices to be overcome.
A person without God might adopt domination and cruelty, or the acquisition of power itself, as the greatest good. Kindness is weakness. Compassion makes you vulnerable. Neither are to be sought.
No amount if evidence that we evolved some altruistic dispositions can address this challenge.
Of course, I think that there is an answer to this challenge. I do not believe that goodness requires God. I think that the goodness of altruism has an explanation in natural terms.
However, I do not see how evolutionary biology can even begin to answer the question.