“An important property of any copying process: it is not perfect. Mistakes will happen.”

“Erratic copying in biological replicators can in a real sense give rise to improvement, and it was essential for the progressive evolution of life that some errors were made… it is ultimately these mistakes that make evolution possible.”

“In the lifetime of a man, things that are that improbable can be treated for practical purposes as impossible… But in our human estimates of what is probable and what is not, we are not used to dealing in hundreds of millions of years.”