Customer Reviews

Ecological Orbits: How Planets Move and Populations Grow

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This book is extremely well written, entertaining, and of general interest. At about 150 pages it is also a very quick read. The equations are mostly moved into appendices. The general public interested in the inner workings of ecology should find this book a fun read.

But make no mistake, this book is really directed at, and a major challenge to, professional ecologists. There are at least three themes woven through this book.
1) The first is a comparison of ecology with physics. Given the recent debate on the ecology listserve (ECOLOG) on whether ecology is a hard or a soft science, this has to be considered a timely topic. The authors are an ecologist with a strong ealry training in mathematical physics and a philosopher of science. Far from bemoaning the shortcomings of the science of ecology, this book boldly asserts that ecology is as proud a science as physics and gives a very detailed and compelling refutation of the idea that ecology is a "soft" or "lesser" science.
2) This book identifies the field of allometry and metabolic energy as a central subject in ecology. Interestingly, one of the harshest critics of ecology (Ron Peters) identified this same field as one of the few "hard" areas of ecology
3) Finally, this book reasons by analogy with physics. A major breakthrough occurred in physics when Galileo and Newton realized that the second derivative of position (i.e. acceleration) was the fundamental quantity, not the first derivative (velocity) as thought for almost 2000 years. They carry this analogy over to ecology and suggest that ecology needs to focus not on deviations from a constant population size, but deviations from a constant population growth rate (i.e. r or lambda).

These themes are elegantly woven together. Many have argued that ecology needs to see a rapprochement between ecosystem science and MacArthurian population interaction dynamics. This book undertakes this, combining themes #2 and #3 (allometry and metabolic energy with simple one and two species population dynamic models). Although several people have done this in a detailed, tactical fashion (e.g. Yodzis, Guttieriez, Getz), this book is the first to attempt to do this in a strategic fashion attempting to derive general principles and understanding. The authors also frequently invoke invariance principles similar to those that are so central in physics. One very simple one is that a predator-prey system should have the same dynamics whether there is one predator chasing five prey or 5 predators chasing 25 prey (since the box that we draw around a system to count the number of individuals is arbitrary anyway).

All of this leads to the central proposition of the book: that the well-known phenomenon of cyclical population dynamics has a simple parsimonious explanation: that 2nd order dynamics (see theme #3 above) of a single species can explain population cycles more simply and elegantly than the traditional model of two trophic levels (predator/prey). This is a radical theory. The authors present considerable evidence, but it will take some time for the ecological community to evaluate these two alternatives.

Whether one is convinced by this central proposition, and even if it ends up being proven incorrect, I think this book is a must read for all ecologists. It contains great wisdom about the nature of ecology as a science, an important attempt to bridge subdisciplines, and a major challenge to current fundamental assumptions.

Ecological Orbits is an introduction to the inertial behaviour of populations. Humbly drawing from physics for the metaphor of how planets move and populations grow, this is a self-claimed "poetic" beginning of a new view as to why populations cycle. The book can be appreciated because of its fairness to traditional and this view, whilst describing how and the limits of metaphor the authors use to facilitate understanding of their new idea. Inertia and maternal inheritance are VERY important and poorly understood by biologists. With the exponentially-growing importance and new advances in understandings in these fields (e.g., epigenetic mechanisms, placticity), I predict this book will remain a less radical and more pertinent foundation in the future.

Additionally, I would like to point out that I appreciate the author's approach to introducing and stimulating new ideas. Every so often, when scientists have new ideas, they feel the need to compose tomes to meticulously and tediously lay out their arguments and counter arguments. This book is at the other end of the spectrum; it produces enough information to be cogent and efficacious, yet stimulating and not overwhelming.