Biologically deterministic arguments have always been pressed into use by those who wish to explain human sexual behaviour while maintaining the status quo. Biological determinism is, in fact, the Daily Mail of scientific inquiry - full of bogus notions about female fidelity versus male promiscuity (it's only fair, you see; he's got more sperm than she could ever use) and the evils of homosexuality (it's against nature, because we were put on earth to make babies). Clearly, the randier strand of Homo sapiens has never been put off by hoary old nonsense extrapolated from the behaviour of voles, but it remains the case that determinists have rarely been fought on their own terms.
Well, now the conservatives have had their day, and it's time for the libertines to start justifying themselves with reference to the bunny wabbits. Judson - or Dr Tatiana, as she unfathomably prefers to be known - is an unusually accessible biologist. Her two core interests are infidelity and homosexuality. We start with my favourite theory (I believe this is a favourite among all females): that most species have more to gain from slapper ladies than slapper gentlemen, owing to the superior quality of babies that are the result of a fierce competition in the Fallopian region. This, to be frank, has been common knowledge since Robin Baker's seminal Sperm Wars (forgive that) six years ago, but it's no less enjoyable for that.
To prove the thesis, Judson sifts deftly through about 17 more species than you've ever heard of. Her central conceit - that the tiny beasties are all little people who have written letters to her - I found rather cloying. The chapters all kick off "Dear Dr Tatiana, I'm a splendid fairy wren!" and, if you think that's bad, try it with some alliteration: "Dear Dr Tatiana, I'm a furious fruit fly!"
At the end of the book, she changes tack to deal with the asexual bdelloid rotifer, which is represented as a guest on The Jerry Springer Show. This is quite annoying as well (when will people understand that you can't parody bad TV unless you actually watch it?). There is some serious overwriting, which diminishes both the pace and vim of this enthusiastic biologist.
That said, Dr Tats has a very generous tone, and despatches old-fashioned notions with authoritative kindness - Bateman, the originator of the men-naughty-women-good model, was simply using the wrong kind of fruit fly for his experiments (a bit like Kinsey and his wrong-sorts-of-prostitutes). Tatiana explains this very pleasantly, where a lesser lady-scientist might scoff. She is also unshakeable in her belief that the juxtaposition of a jaunty conversational tone and dirty words cannot fail to be amusing, and I'm with her on that. "After sex," she writes, in reference to the tropical cockroach, "females feast on anal secretions produced by their mates, eaten right off the plate, so to speak."
There is clarity here; she would never let a bit of homosexuality or incest go without explaining exactly how it survives natural selection, producing as it does no (or rubbish) offspring. The main quibble I'd have with the book lies in its thoroughness - no species with any claim to sexual idiosyncrasy is left unexamined. In consequence, you find every conceivable permutation of male- and female-offspring behaviour here. Some are monogamous, some are promiscuous, some stun one another with hormones, some explode after birthing, some sex up their sisters, and so on, ad infinitum. The problem lies precisely with this variety - if the layman is ever to be all that interested in the sexual vicissitudes of the scallop, it has to be because they relate to those of human beings in some way. And because this book supplies such endless possibilities, there is no final evolutionary truth from which you could extrapolate any behaviour. All you're left with is an awful lot of facts, and a couple of truisms - one, all behaviour evolves for the furtherance of the species; two, that does not necessarily mean that homosexuality is weird, or that men have the upper hand.
This is an invaluable addition to any debate about sexual or reproductive ethics, one of those books that had to be written, but nobody should have to read.
Zoe Williams writes for the Guardian