Read this back to back with The Selfish Gene, which I do not recommend doing unless you enjoy feeling stupid twice in one month. The Selfish Gene is popular science with real teeth, this one is just science, aimed at biologists arguing with other biologists, and I don’t have a biology degree, I have a library science degree and a library card I use aggressively, so a decent chunk of the middle chapters went past me the way technical spec docs do at work when someone forgot to define their acronyms.

Here’s the thing though, I kept going, and the glossary in the back is genuinely bad, I flipped to it more than once and came away no clearer than when I started, which tells you something about how dense the actual argument gets. But the payoff chapters at the end, where he finally lands on the extended phenotype concept itself, the idea that a beaver’s dam or a parasite’s manipulation of its host is as much a product of that creature’s genes as its own body is, are worth the slog. That’s the one genuinely original idea in a body of work that’s mostly, brilliantly, popularizing other people’s science, and it shows.

The middle stretch spends a lot of energy defending the gene’s-eye view from critics who, thirty years on, I mostly don’t need convincing about, and the chapter on outlaw genes dragged for me specifically, felt like watching someone win an argument that already ended. If you’ve only read The Selfish Gene and liked it, know what you’re getting into, this is postgraduate reading, not more of the same at the same altitude. Four stars, not five, because a book that makes its ideal reader a working biologist isn’t quite doing its job for the rest of us, even when the ideas underneath are this good.