Woody Allen is fond of saying that the human brain is his second favorite organ. For what purpose did the human brain evolve is a question that has puzzled scientists for decades, and was answered in 2010 by Colin Blakemore, an Oxford neurobiologist who argued that a mutation in the brain of a single human being 200,000 years ago turned intellectually able primates into a super-intelligent species that would conquer the world. Homo sapiens appears to be genetic accident.