Yes, the title of this post is a direct reference to the book of the same title by Richard Dawkins. Whatever you may think of Dawkins himself, his science has ended up being extremely influential.
The title is, by the author’s own admission, rather misleading. The idea is not to think of genes as agents with purpose or moral capacity (they’re just chemical strings after all). Instead, consider the following scenario:
A women and her husband stand before the queen. The women is pregnant, just starting to show. The man is putting on a brave face, as his wife has just killed a man. The punishment is death.
The man steps forward, shaking. “My queen”, he says, “I confess”. His wife lets out a whimper. “I am guilty of this crime, not she”. He pauses as the weight of what he has done sinks in, then continues. “I accept the consequences of my crime”.
It is a natural and obvious connection to draw that, given survival of the fittest and basic genetics, the genes that survive will be ones that make their respective animals survive. But on this understanding, the above scenario makes no sense. Why would the man confess to a crime he did not commit, when it leads to his almost certain death? Does not survival of the fittest imply that such behaviour be weeded out over time? We could argue that this altruistic behaviour is not representative and in fact will be weeded out, but such behaviour has been recorded again and again throughout history.
Instead, we must notice that while the man will certainly die, his genes will not. In fact, half his genes are at that moment present in his unborn child, who has a full and long life ahead if the man makes this sacrifice. Humanity tends to see this sacrifice as noble and good in some sense, but it is really much simpler than that. The man is not doing what is best for himself; he is doing what is best for his genes.