Life, as our physicist mother never tired of reminding my sister and me, is a cosmic accident—a view held by better known physicists such as Murry Gell Mann. our universe began 13.7 billion years ago, in what we call the Big Bang. On our planet, with the help of ultraviolet rays and lightening, the chemical building blocks of life developed, leading to the first living cell 3.5 to 4 billion years ago. Starting about 2 billion years ago, sexual reproduction by simple multicellular organisms unleashed waves of evolutionary innovations. About six million years ago, a genetic mutation in chimpanzees led to the first humanlike apes. Homo sapiens appeared extremely recently, 200,000 to 100,000 years ago, dominated other human types around 30,000 years ago, and had spread to most of the planet by around 13,000 years ago. A lot of things had to go right for us to get to this point. But the "Goldilocks" conditions in which we flourish cannot endure indefinitely. To date, around 99.9 percent of all species over to have inhabited Earth have become extinct.
-Niall Ferguson, Doom: The Politics of Catastrophe