Evolutionary biology ought to be a compelling subject. Not only does it help explain how all the weird and wonderful creatures that surround us came about, but it is basically about sex. Somehow, though, science teachers and textbooks often conspire to make it seem boring.

They ought to take a leaf out of Olivia Judson's fabulously entertaining new book. Dr Tatiana's Sex Advice to All Creation is a brilliantly devised and humorously written "advice column" for animals about their sex lives. As goofy and boorish as the sexual practices of most creatures may be, there is method in their madness. Ms Judson, an award-winning journalist and evolutionary biologist, masterfully explains why we should even care. Sex is never simple, but some creatures are in their own league of complexity. We have sex in all its kinky, eccentric variety to thank for all the beauty of nature.

Dr Tatiana offers her bewildered and distressed "patients" advice on their outlandish sexual habits and customs. Thus we learn why teeth on the back can improve the sex lives of certain species, why "the act" can be a death sentence for others and why incest is sometimes best. Some daring souls have even done away with sex altogether: philodina roseola (bdelloid rotifers to you and me) are virgins; no one in their family has had sex in over 85 million years. Their ancestors abolished males ("They said we were better off without them"), so they reproduce via cloning--a scandal in evolutionary terms.

"Waiting for Sperm in Ohio", a drosophila bifurca (fruit fly), writes in, upset that nature has given him a raw deal: it takes him three weeks to make a single sperm. "You're right," replies Dr Tatiana sympathetically, "it's not fair. Why should a fruit fly three millimetres long have to make sperm that measure 58 millimetres? A human is far bigger than you, but gets away with sperm one thousand times smaller. Indeed, if a man were to make sperm on your scale, it would be as long as a blue whale. Now that I'd like to see."

As with her subjects' sexual practices, there is sanity behind the quirkiness of Ms Judson's premise. It is astutely explained in the three parts of her book. "Let Slip the Whores of War" covers a subject dear even to humans--gender differences and their consequences on all walks of life. Part two, "The Evolution of Depravity", delves into some less savoury topics, including cannibalism and rape. It also explains why "'til death do us part" does not apply to most creatures: monogamy is deviant behaviour in biology. The final section, "Are Men Necessary?", requires no explanation of its worth (to us females) or its interest to most (female, again) readers. Beauty really is only skin deep. But who would have thought Mother Nature is so racy?