Evolution Slows As Species Numbers Rise

A British study suggests the rate at which new species are formed in a group of animals decreases as the number of different species in the group increases.

The Imperial College London-led research team said the findings suggest competition among closely related species for food and habitat becomes more intense the more species there are.

The number of niches in any given region is finite, and our research supports the idea that the rate of speciation slows down as the number of niches begins to run out, said Albert Phillimore of the Natural Environment Research Council’s Center for Population Biology and lead author of the study. In essence, it seems like increased competition between species could place limits on the number of species that evolve.

The study appears in the journal PLoS Biology.