So it is best to keep an open mind and be agnostic. At first sight that seems an unassailable position, at least in the weak sense of Pascal's wager.… - Richard Dawkins

There may be fairies at the bottom of the garden. There is no evidence for it, but you can't prove that there aren't any, so shouldn't we be agnostic with respect to fairies?

We humans are an extremely important manifestation of the replication bomb, because it is through us – through our brains, our symbolic culture and our technology – that the explosion may proceed to the next stage and reverberate through deep space.

Natural selection is like artificial selection, but without the human chooser. Instead of a human deciding which offspring shall die in which shall reproduce, nature ‘decides’. The quotation marks are vital because nature doesn’t consciously decide. This might seem too obvious to emphasize, but you’d be surprised by the number of people who think natural selection implies some kind of personal choice. They couldn’t be more wrong. It just is the case that some offspring are more likely to die while others have what it takes to survive and reproduce. Therefore, as the generations go by, the average, typical creature in the population becomes ever better at the arts of surviving and reproducing. Ever better, I should specify, when, when measured against some absolute standard.

They are in you and me; they created us, body and mind; and their preservation is the ultimate rationale for our existence. They have come a long way, those replicators. Now they go by the name of genes, and we are their survival machines.