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-this book 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.