The Serengeti Rules

Sean B Carroll
Princeton University Press, £13.99

There is a certain freight that comes with reviewing the new edition of a book that has been out for nearly 10 years, was well received the first time around and gave rise to a multi-award-winning documentary film. In short, whatever I have to say about The Serengeti Rules should probably be taken with a pinch of salt.

Nonetheless, there are things to say, the first of which is that it’s an unusual book, structure wise. Ostensibly an account of the workings of ecosystems at the population and community levels – and of the pioneering scientists who elucidated those workings – it is also very much a game of two halves, so to speak. The first 50 pages are mostly given over to a fairly granular description of biomolecular feedbacks operating in human cells, and only after that do we get to the wildebeest, lions and hyenas that the reader might have been expecting.

The parallels between these two systems are undoubtedly clear. Both involve components interacting in ways that promote or inhibit one another, often leading to double-negative feedback (i.e. the phenomenon wherein one molecule/species inhibits another molecule/species that had been inhibiting a third molecule/species). Both required some neat experiments and insightful interpretation to fully understand.

Having said that, it wasn’t clear to me quite what I was supposed to take from this similarity of process. The molecular story did not inspire or otherwise educate the scientists who worked on the ecological scale (as far as I can make out), so it cannot be that the former is a necessary explanation for the discoveries of the latter. This leaves me to suppose that the molecular chapters are there to provide an analogy that helps us to understand the so-called ‘Serengeti rules’ that govern ecosystems. This will be mightily effective for anyone who is innately or educationally more familiar with biochemistry than with ecology, but I suspect that those readers are rare in the population as a whole, and even rarer in a readership for a book that appears, from its cover, to be about ecology.

With that in mind, it struck me that while the book is fascinating on the history of the discovery of the eponymous rules, it is unavoidably dealing with concepts that are now, I suspect, very familiar. There are a couple of points in the book where Carroll sets up an ecological conundrum, only to temporarily withhold the solution in a suspense-generating gambit, yet in each case the solution in question seemed trivially obvious – and I don’t think that’s because your reviewer is an ecologist.

However, like I said, you should take all this with a pinch of salt. Besides, I enjoyed the book, despite my quibbles, and it serves as a readable primer on food-web interactions and related high-level ecological processes.

Andy Dobson

Reviewed by Andy Dobson