Vexen Crabtree's Blurty

Life on a billion planets?
The formost evolutionary biologist, Prof. Richard Dawkins, makes some comments on the likelihood of life evolving on alien planets:

“It has been estimated that there are between 1 billion and 30 billion planets in our galaxy, and about 100 billion galaxies in the universe. Knocking a few noughts off for reasons of ordinary prudence, a billion billion is a conservative estimate of the number of available planets in the universe. Now, suppose the origin of life, the spontaneous arising of something equivalent to DNA, really was a staggeringly improbable event. Suppose it was so improbable as to occur on only one in a billion planets. [...] Even with such absurdly looking odds, life will still have arisen on a billion planets - of which Earth, of course, is one.”

Text from "The God Delusion" by Prof. Richard Dawkins, p137-8.

I have added this text to my index page: "Alien Life: Evolution, Similarities to Earth, War and Paranoia" by Vexen Crabtree