The Unified Neutral Theory of Biodiversity and Biogeography
Despite its supreme importance and the threat of its global crash, biodiversity remains poorly understood both empirically and theoretically. This ambitious book presents a new, general neutral theory to explain the origin, maintenance, and loss of biodiversity in a biogeographic context.
Until now biogeography (the study of the geographic distribution of species) and biodiversity (the study of species richness and relative species abundance) have had largely disjunct intellectual histories. In this book, Stephen Hubbell develops a formal mathematical theory that unifies these two fields. When a speciation process is incorporated into Robert H. MacArthur and Edward O. Wilson’s now classical theory of island biogeography, the generalized theory predicts the existence of a universal, dimensionless biodiversity number. In the theory, this fundamental biodiversity number, together with the migration or dispersal rate, completely determines the steady-state distribution of species richness and relative species abundance on local to large geographic spatial scales and short-term to evolutionary time scales.
Although neutral, Hubbell’s theory is nevertheless able to generate many nonobvious, testable, and remarkably accurate quantitative predictions about biodiversity and biogeography. In many ways Hubbell’s theory is the ecological analog to the neutral theory of genetic drift in genetics. The unified neutral theory of biogeography and biodiversity should stimulate research in new theoretical and empirical directions by ecologists, evolutionary biologists, and biogeographers.
From the Back Cover
"This provocative and enlightening work, deeply original and supported by some of the most extensive field research ever conducted in biology, will be regarded as one of the most important contributions to ecology and biogeography of the past half century."–Edward O. Wilson, author of Biodiversity
"This book should be a true landmark, a revolutionary and compelling treatment that can do for community ecology what neutrality theory did for molecular and population genetics. Building on the conceptual foundations of island biogeography, Hubbell erects a grand null hypothesis establishing, in this case, a novel conceptual framework for virtually all further attempts at interpetating the composite distributions and abundances of species, in any environment and at any trophic level. I hope that this work will be discussed and embraced by the ecological community to the extent that it clearly merits."–John Avise, University of Georgia
"This book presents a new theory that seeks to unify the two approaches of population biology: biodiversity and biogeography. I expect that it will immediately be considered essential reading by biogeographers and ecologists. . . . Its review of the literature is extensive and valuable. The author’s writing style is graceful and reads well."–Jared Diamond, author of Guns, Germs, and Steel
"This book is important and inspiring. It will surely stimulate renewed and long overdue interest in broad-scale patterns of species distributions and abundances–the core of community ecology."–Mark A. McPeek, Dartmouth College
About the Author
Stephen P. Hubbell is Professor of Plant Biology at the University of Georgia and Staff Scientist at the Smithsonian Tropical Research Institute in Panama. He is the author of more than one hundred papers in tropical plant ecology, theoretical ecology, and plant-animal interactions. He has been awarded a Guggenheim Fellowship and the Pew Scholar Award in Conservation and the Environment. He is Chairman of the National Council for Science and the Environment (formerly the Committee for the National Institute for the Environment) and the inventor of Extinction: The Game of Ecology.
Towards a unified thoery, but not there yet, September 5, 2001
A couple of years ago, Dr. Jim Brown (Univ. New Mexico) wrote an article in the National Center for Ecological Analysis and Synthesis (NCEAS) website indicating that he had not seen any really significant new ideas in ecology during the last few year. Well, we have one.
In the hierarchy of biological systems, ecology deals with the highest and most complex levels. Explanation for patterns of abundance and distribution of organisms have been either too specific that only applies to a few species or even one, or too general that can not be tested (remember the ghost of competition’s past).
Ecologists working at the community level have mostly been guided by the general principle that interactions tend to determine the diversity of communities. On the larger scale of biogeography, researchers considered that local diversity tends to be a function of a regional species pool. This debate became very contested in the early 1980’s and continued for almost a decade, without any meaningful progress. Nonetheless, significant achivements in both areas of inquiry were made.
Hubbell takes advantage of the increased large-scale reasearch in community ecology (like the Smithsonian-MAB biodiversity network of plots) coupled with the ever more manipulative and reductionist approach to biogeography. Is important to add here Hubbell’s own contribution to biodiversity research is substantial. Furthermore, the originality of the work is what sets this monograph appart from the last few in the series. The application of random walk models (i.e., ecological drift) to the organization of communities is not a truly new approach. What make is unique is that then he incorporates immigration and extinction rates across space (classical MacArthur-Wilson), and can then predict a range of abundances and distributions. He supplies ample data from tropical systems that agree with model’s predictions. The more interesting aspect is when the data doesn’t agree. Here there is plenty of productive work to be performed.
One point that Hubbell makes concerning the "triviality" of the nuetrality assumption. Can there be cases when the differential survival of individuals lead to deviations from the theory’s prediction? I think that the assumption of neutrality is not as trivial as Hubbell makes it.
Overall, is probably one of the most intriguing and original works of the last decade. If you are interested in ecology, biogeography, and even conservation, this book will challenge what you know and how should we look at patterns and process of biodiversity.
Good theory, poor explication, October 18, 2006
Hubbell’s work is interesting and thought-provoking. Unfortunately, his writing ability leaves a lot to be desired. As an applied mathematician working with biologists personally I think you should:
1. Specify your (mathematical) model *without* examples or justifications first.
Hubbell mixes his models with examples and rambling justifications. Poorly constructed ones if you ask me. This makes it hard to pull out what exactly the model is sometimes.
2. Make derivations clear and concise and if complicated put them in appendices. Hubbell does none of these. His mathematical reasoning and writing is far below the standard in science and although impressive for an ecologist, substandard for anyone else. He would have strongly benefitted from having a trained mathematician co-write or at least edit his mathy sections. Many of the results are either well known or would be explained differently by someone trained in the explication of mathematics. The importance of this is huge since the result is sometimes his statements are totally unclear. For example, on page 124 he says "as the sample size increase towards infinity…" This is a sample from a finite sized population. So he should be clear and say either sample with replacement, or also taking the population size to infinity, (which is it!) otherwise it doesn’t make sense.
I also find his egoism (common in my experience with ecologists) disappointing. While he may have come up with a new theory of biodiversity, he did not come up with many of the underlying models. Unfortunately, he barely pays any respect to the countless other people who paved the way for his results. For example, his species abundance distribution is just the Ewen’s sampling formula from population genetics, derived in 1972. In fact, the model side of the entire theory comes straight out of population genetics. Yes it explains something different, but it would be nice to see something at least some acknowledgement of that (something he is clearly aware of since he cites many of the popgen papers).
Also, the reference list is incomplete and the index is one of the worst I have come across recently. Paying for a good indexer is always worth the money.
In short, the ideas in this book are important, but the book itself is cluttered and not as clear as it could be. So I average 5 stars and 1 star and get 3 stars.