Please advise your friend to understand that the acceptance of evolution does not constitute the removal of morals. Moral behaviors come from many sources, but my favorite by far is that they are derived from the equal need of society, basically the golden rule on steroids. If you choose to kill me, you in turn sacrifice your own right to live. If you choose to behave cruelly, you will be forced to suffer the same cruelties.
This means that ensuring the survival of your genes should only constitute finding a suitable mate with good genes, and reproduce as often as possible. however, there is a drawback to this. Given the expenses of a child's existence, we are generally forced to have only a few children, lest we lose our money, our means of survival.
While eliminating the competition would be a way to ensure the survival of your genes, it would also probably constitute something along the lines of extreme mass genocide. This is why such behaviors are generally discarded for practical solutions for your objective.
This means that ensuring the survival of your genes should only constitute finding a suitable mate with good genes, and reproduce as often as possible. however, there is a drawback to this. Given the expenses of a child's existence, we are generally forced to have only a few children, lest we lose our money, our means of survival.
While eliminating the competition would be a way to ensure the survival of your genes, it would also probably constitute something along the lines of extreme mass genocide. This is why such behaviors are generally discarded for practical solutions for your objective.