Paradox of the clumps

摘要

A fresh look at an established model in ecology has generated insights into how species coexist with each other. But it has also raised a vexed question: what constitutes the ecological identity of species? Classical ecology discovered the principle of competitive exclusion - or, more pithily, one species, one niche'. In order to coexist, species must have their own individual way to make a living, otherwise the superior competitors would exclude the inferior. Niches might preexist: for example, if there are two types of seed in the environment, this provides two niches for specialist seed-eating birds, Or niches might be created by a species evolving into openings in the 'marketplace' of their ecology.