Richard Dawkins talks about the way in which science helps to inform moral decision-making in this science and morality speech. While Dawkins points out that scientists don't typically set out to settle moral debates, he does believe that scientific facts can help inform people so that they can better decide what is moral.
Dawkins uses abortion as an example in this speech. Abortion is a moral hot topic because some individuals wouldn't consider an unborn fetus to be a person, while others would. Dawkins says that a scientist could tell people at what point a fetus develops a nervous system, which without a doubt makes it a human being. Dawkins also discusses evolution and the ancestors of humans. He claims that when one considers that evolution is a proven fact, it gets harder to separate one species from another because humans evolved from apes. If one can't separate apes from humans it gets harder to justify placing human life above animal life in terms of importance.