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Adrian Forsyth – A Natural History of Sex

January 9, 2008

4. A Natural History of Sex: The Ecology and Evolution of Mating Behavior by Adrian Forsyth (1986)

Length: 192 pages

Genre: Non-Fiction; Science – Biology

Started: 04 January 2008
Finished: 09 January 2008

Summary: This is a pop-science book that attempts to tackle a broad range of questions about sex and mating across the animal kingdom (plants do get brought up, but the focus is mainly on animal behavioral ecology and evolution). It’s broken down into a series of relatively short chapters: Sperm Competition; Penetrating Solutions (alternative male mating tactics); Consuming Passions (“suicidal monogamy” a la black widows); Honest Salesmen (female mate choice); New Sneakers (more alternative male mating tactics); Role Reversal; Abortion and Infanticide; Female Versus Female; Milk and Honey (human sexual selection); What Good is a Bastard? (hidden estrus, female promiscuity, and cuckoldry); Orgasm and Inertia (function of female orgasm); Smelling (pheromones); Sex Change; Incest and Outcest; Islands of Incest; Virgin Birth (parthenogenesis); and Why Sex Persists.

Review: It’s long been my opinion that most biologists – and especially most biologists interested in mating behavior – never really outgrew that early adolescent mindset that finds the entire concept of sex fascinating – and funny. The non-human world certainly provides a wealth of examples of sexual practices that – by human standards – are in turns bizarre, horrifying, and slightly hilarious. The motivation for studying these phenomena might be “Hee! Weird sex!”, but the goal is to understand not only what happens during the copulatory acts of other species, but also why – what evolutionary benefits do these seemingly bizarre practices have for the individuals that engage in them? This book was originally published in 1986, and at the time it may have been an invaluable resource for introducing non-biologists (or non-behavioral-ecologists) to the diversity of reproductive practices and to the means of thinking about them from an evolutionary mindset. However, nowadays there are several other options that accomplish this task with 1) more up-to-date research and stronger scientific foundations; 2) better and more engaging writing; and 3) better resources for readers who are more than casually interested.

The writing is not bad, per se, but is certainly not as clear as it could be. Forsyth is prone to evolutionary storytelling – positing an adaptational benefit to every behavior and phenomenon that we’ve observed and dismissing the suggestion that it’s an evolutionary by-product that’s not under direct selection, even with a lack of evidence either way. In the 20 years since this was written, some of his “selection stories” have accumulated evidence to support them, while others have been disputed, or had alternative hypothesis proposed (and supported). In any case, it’s difficult to check, since while he does provide a “Further Reading” section for each chapter, it’s not annotated or complete, and – horrors! – nothing is cited in the text itself, making it difficult to check his facts or his interpretation against the primary literature.

The range of topics covered was similarly strange… The “Why Sex” chapter came last instead of first, where it would have made more sense, and the rest of the chapters bounced around, spending a lot (too much) time on some topics while giving short shrift to others. Basically, this book hit on topics all over the field of reproductive ecology and evolution, but in a very scattershot way. It’s as if someone presented you with brick red, bright yellow, chartruese, kelly green, forest green, indigo, and deep violet, and said “look, a spectrum!” The range is there, but there are conspicuous gaps, and the reader would be better served picking a book that either was written specifically on the area of interest, or one that did a better job giving an overview of the whole field.  2 out of 5 stars.

Recommendation: This may have been good when it was written, but it’s outdated by now. Dr. Tatiana’s Sex Advice to All Creation by Olivia Judson is a more comprehensive and more readable book in the same vein, and Tim Birkhead’s Promiscuity is a little more specialized, but hits a lot of the same issues – I’d recommend either of those over this book.

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  • p. 11: “By definition, a male is nothing more than an individual that produces small sex cells, the gametes used to make a new individual. No other masculine excrescences are necessary or sufficient to distinguish him from the female, the one that produces large gametes.” – something that bulges out or is protuberant or projects from its surroundings.
  • p. 57: “Since they are trying to flood, anonymously and quickly, as many eggs as possible with their milt, a small body with large testes makes sense.” – the sperm-containing secretion of the testes of fishes.
  • p. 121: “‘The principle is clearly illustrated in the case of castrated animals, for one sees the bull, the boar, the ram and the cock, very fierce animals, which having been deprived of their testicles remain very cowardly; so one sees a ram drive before it a flock of wethers a cock put to flight a number of capons.’” – a castrated ram.
One Comment leave one →
  1. activeneoteny permalink
    August 15, 2008 11:09 pm

    Sexual selection in a patrifocal society has the repercussion of female infanticide. Visit There is method in the madness of humans.

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