Toward a unifying theory of biodiversity

Ecologists have long agreed that to coexist species must be sufficiently different (1, 2). This worldview was challenged when Stephen Hubbell published his neutral theory of biodiversity showing that species that are essentially equal should also be able to evade competitive exclusion (3). Although this neutral theory inspired a fresh look at biodiversity, it also met resistance as it seemed to violate the deeply held belief that all species are...