On a Sunday in summer 2008, I was sitting in the library at the California Academy of Sciences, alone on the third floor of the brand-new Renzo Piano-designed building. I no longer have this kind of access, but at the time I was able to move at will into the temperature-controlled stacks, to consult a century’s worth of books and periodicals elucidating arguably the most important concept of all time, the theory of evolution by way of natural selection. I was writing a book (