Statistical Mechanics of Ecological Systems: Neutral Theory and Beyond

TL;DR

This paper reviews the development, successes, and limitations of Neutral Theory in ecology, highlighting its interdisciplinary impact and discussing future directions for incorporating non-neutral elements into ecological models.

Contribution

It provides a comprehensive synthesis of Neutral Theory's quantitative results and extensions, making complex concepts accessible to physicists and ecologists alike.

Findings

Neutral Theory explains many patterns in ecosystem organization.

Theoretical predictions have matched some empirical data.

Extensions of NT suggest ways to include non-neutral factors.

Abstract

The simplest theories often have much merit and many limitations, and in this vein, the value of Neutral Theory (NT) has been the subject of much debate over the past 15 years. NT was proposed at the turn of the century by Stephen Hubbell to explain pervasive patterns observed in the organization of ecosystems. Its originally tepid reception among ecologists contrasted starkly with the excitement it caused among physicists and mathematicians. Indeed, NT spawned several theoretical studies that attempted to explain empirical data and predicted trends of quantities that had not yet been studied. While there are a few reviews of NT oriented towards ecologists, our goal here is to review the quantitative results of NT and its extensions for physicists who are interested in learning what NT is, what its successes are and what important problems remain unresolved. Furthermore, we hope that this review could also be of interest to theoretical ecologists because many potentially interesting results are buried in the vast NT literature. We propose to make these more accessible by extracting them and presenting them in a logical fashion. We conclude the review by discussing how one might introduce realistic non-neutral elements into the current models.