In contradistinction to the more populist of science authors, Oxford zoologist Mark Ridley (not to be confused with Matt Genome Ridley) is unafraid to pitch his acclaimed books (like Evolution, and Animal Behaviour) at a discerning and cerebral audience. In other words don't go reading this analysis of genetic and sexual complexity expecting laugh-a-minute anecdotes about transvestite sparrows.
That said, those who are willing to persevere through the dense and unashamedly highbrow text will find an interesting debate cogently and wittily argued. Ridley's self-posed question is why such complex beings as swans, gibbons and journalists should have arisen, given an evolutionary process far more favourable to the replication of simple organisms. After all, each time we have sex, reproduce and thus copy our DNA, we are attempting the equivalent of xeroxing James Joyce's Ulysses. Mistakes can and will creep in. So why bother?

Ridley's search for an explanation of this puzzle leads him up some fairly precipitous intellectual mountains. Nor is he unafraid of tackling the wilder kinds of speculation: at one point he considers the sex lives of angels--or any putative beings superior to homo sapiens. Readers willing to accompany the author on this demanding expedition, and stretch their brains as a result, will find the exercise as stimulating as it is edifying. --Sean Thomas