"I don’t know [why we're here]. People sometimes say to me, ‘..." — David Attenborough quote meaning

I don’t know [why we're here]. People sometimes say to me, ‘Why don’t you admit that the humming bird, the butterfly, the Bird of Paradise are proof of the wonderful things produced by Creation?’ And I always say, well, when you say that, you’ve also got to think of a little boy sitting on a river bank, like here, in West Africa, that’s got a little worm, a living organism, in his eye and boring through the eyeball and is slowly turning him blind. The Creator God that you believe in, presumably, also made that little worm. Now I personally find that difficult to accommodate…