What species occur where, and why, and why some places harbor more species than others are basic questions for ecologists. Some species simply live in different places: fish live underwater, birds do not. Adaptations follow: most fish have gills; birds have lungs. But as Patterns in Nature reveals, not all patterns are so trivial.
Bringing up to date a critical debate in the field of community ecology between Jared Diamond and colleagues Daniel Simberloff and Edward F. Connor – in which Connor and Simberloff claimed to have demonstrated that island communities did not differ from random expectations – Patterns in Nature undertakes the identification and interpretation of nature's large-scale patterns of species co-occurrence to offer insight into how nature truly works. Travel along any gradient – up a mountain, from forest into desert, from a north-facing slope to a south-facing one, from low tide to high tide on a shoreline, from Arctic tundra to tropical rain forests – and the species change. What explains the patterns of these distributions? Some patterns might be as random as a coin toss. But as with a coin toss, can ecologists differentiate associations caused by a multiplicity of complex, idiosyncratic factors from those structured by some unidentified but simple mechanisms? Can simple mechanisms that structure communities be inferred from observations of which species associations naturally occur?
While the answers to these questions are not yet entirely clear, Patterns in Nature forces us to reexamine assumptions about species distribution patterns and will be of vital importance to ecologists and conservationists alike.
Preface
Part I. The Distribution of Species on Islands
Chapter 1. Patterns or Fantasies?
Species Co-occurrences
The Night Sky Effect
Patterns in Nature
Finding the Null
What This Book Is About
How This Book Is Organized
Chapter 2. Diamond’s Assembly Rules
Robert MacArthur, 1930–1972
Special Islands and Their Birds
What Is a Checkerboard Distribution?
Incidence
The Theoretical Context
The Cuckoo Doves
Patchy Distributions
Summary
Chapter 3. The Response of Connor and Simberloff
The Backlash
How Likely Are Checkerboards?
Prior Expectations
The Analysis of Vanuatu
Summary
Part II. A Technical Interlude
Chapter 4. How to Incorporate Constraints into Incidence Matrices
Definitions and Notation
The Numbers of Null Matrices and the Effect of Constraints
The Hypergeometric Distribution
The Three Ecological Constraints Proposed by Connor and Simberloff in Their Studies of Birds and Bats on Islands
Incidence
Why Constraints? And What Does “Representative” Mean?
Summary
Chapter 5. How to Fill the Sample Null Space
Null Space Creation Algorithms
Creating a Uniform Random Sample Null Space
The Trial-Swap Algorithm
Summary
Chapter 6. How to Characterize Incidence Matrices
Then You Need a Metric . . .
The Metric of Connor and Simberloff (1979)
Wright and Biehl (1982)
Harvey et al.’s (1983) Review of Null Models in Ecology
Stone and Roberts (1990, 1992) and Roberts and Stone (1990)
Why Ensemble Metrics Fail—An Example
Summary
Part III. Reanalysis and Extensions
Chapter 7. Vanuatu and the Galápagos
The Birds of Vanuatu
The Birds of the Galápagos
Summary
Chapter 8. The Birds of the Bismarck and Solomon Islands
The Issue of Superspecies
The Patterns
Taxonomic Sieving and Incidence Effects
Which Genera Develop Checkerboards?
Caveats
When the Incidences Do Not Overlap
Summary
Coda
Chapter 9. Species along a Gradient
The Herptofauna of Mount Kupe, Cameroon
Why Do the Results Differ from Previous Results?
The Second Question: Do Species Form Distinct Communities?
Summary
Chapter 10. Applications to Food Webs: Nestedness and Reciprocal Specialization
Nestedness
Groupings of Species Interactions
Summary
Chapter 11. Coda
MacArthur’s Original Vision
The Patterns Themselves
The Need for Null Hypotheses
References
Index
James G. Sanderson is a TEAM research scientist at Conservation International's Center for Applied Biodiversity Science. He is coauthor of Small Wild Cats: The Animal Answer Guide.
Stuart L. Pimm is the Doris Duke Professor of Conservation Ecology at Duke University. He is the author of The World According to Pimm: A Scientist Audits the Earth, The Balance of Nature?: Ecological Issues in the Conservation of Species and Communities, and Food Webs, the latter two published by the University of Chicago Press.
"Two fundamental questions of community ecology concern large-scale patterns of species communities. Do such patterns really exist? If they do exist, how can they be explained? Difficulties in answering these questions have given rise to much debate over the course of the last forty years. By assembling massive new databases and powerful new analytical techniques, Sanderson and Pimm have now produced this wonderfully clear account of this wonderfully complex subject. This book will be the standard reference work for everyone interested in the patterns of species communities."
– Jared Diamond, University of California, Los Angeles, author of the Pulitzer Prize-winning Guns, Germs, and Steel
"This stimulating book is centered upon an attempt, inspired by Robert MacArthur, to explain patterns of co-occurrences of bird species that might be caused by competition. Are the patterns real or no different from what is expected by chance? The authors adopt an engaging conversational style in confronting the contentious issues and surprising complexity of distinguishing between these stark alternatives. The book will be valuable in showing how ecologists grapple with fundamentally different opinions on how to analyze data."
– Peter R. Grant, Princeton University, coauthor of 40 Years of Evolution: Darwin's Finches on Daphne Major Island
"A very interesting book on large-scale species distribution patterns, this is not a repeat of what has been published voluminously on the debate between Diamond and Connor/Simberloff, but a well-written, fairly balanced, and updated account of the positive contributions to science from both camps and the lessons that we all can learn from such heated debates. For those who are interested in island biogeography, for those who are enthused by 'laws' in ecology, and for those who are intrigued by historical developments in community ecology and beyond, this is a fascinating read. And for those who want to learn useful techniques and algorithms in null model analysis, Patterns in Nature is an entertaining and valuable book."
– Jianguo (Jingle) Wu, Arizona State University