The Nature paper also shows how Fisher's distribution changes when the immigration of species into an ecological community is restricted. This is a famous unsolved problem in the Theory of Island Biogeography published by renowned biologists E. O. Wilson and Robert MacArthur 36 years ago.
For the past half century, the field of ecology has operated inside a Darwinian paradigm that assumes species in nature are "niche-differentiated" - that is, they have largely separate roles to play in biological communities. During that time, scientists have tried to measure the characteristics of species to predict their distribution and abundance in nature by measuring their "niche characteristics."
Ecological nature is, many scientists assert, fundamentally asymmetric because of the inherent uniqueness of species in ecological communities. This is called the Niche Assembly Theory. According to this theory, species coexist in closed assemblages that are in equilibrium or near equilibrium.
"These niche assembly models have not really worked as well as we hoped, though we have learned a lot," said Hubbell. As it turns out, there is a great deal scientists do not yet know about how species form ecological communities. Predictive ecological theories that provide real-world answers are needed for issues ranging from protecting biological diversity to improving land management laws.
Starting in 1979, Hubbell began to develop a theory that grouped similar species instead of assuming all species are different and act differently. Over time, he began to discover that many patterns that had heretofore been explained by "niches" might have a simpler explanation.