Richard Dawkins says
Evolution is a fact. Beyond reasonable doubt, beyond serious doubt, beyond sane, informed, intelligent doubt, beyond doubt evolution is a fact.
Physicists already have reason to suspect that our universe – everything we can see – is only one universe among perhaps billions. Some theorists postulate a multiverse of foam, where the universe we know is just one bubble. Each bubble has its own laws and constants. Our familiar laws of physics are parochial bylaws. Of all the universes in the foam, only a minority has what it takes to generate life. And, with anthropic hindsight, we obviously have to be sitting in a member of that minority, because, well, here we are, aren’t we?
We explain our existence by a combination of the anthropic principle and Darwin’s principle of natural selection. That combination provides a complete and deeply satisfying explanation for everything that we see and know.
But why give any credence to the primitive notions of a late 20th century domesticated primate whose DNA is 50% identical to that of a banana?
(See also Theism, Atheism, and Rationality.)