Eight Little Piggies, by Stephen Jay Gould

First published in 1993, this collection of essays reminds us of the loss to popular science when Gould died aged 61 in 2002. His fertility is exemplified by the title essay, which refers to the eight toes of the first land vertebrates. Our five digits may be merely contingent, writes Gould, but "contingent events have made our world... Think of arithmetic with base eight." Elsewhere, he defends Archbishop Ussher's dating of creation to 4004BC, extols Nairobi's recycling market and ponders an upside-down fossil called Hallucigena. Witty, paradoxical, polymathic, Gould is a wonderfully lively advocate for evolution.