It is known that biodiversity is unevenly distributed across the planet. But why do some islands such as the Galápagos and Hawaii harbour so many unique species of birds? In the 1960’s, Robert MacArthur & Edward Wilson proposed what was to become a highly influential theory in biology: the Theory of Island Biogeography. This theory predicts the number of species expected on any given island as a function of the area (size) of the island and its isolation (distance) from the mainland.
Remarkably, to date no study has shown on a global scale how island area and isolation determine the rates at which species colonise new islands, evolve new types or go extinct. These relationships have remained elusive for decades.
However, in a new study published today in Nature, a team of ornithologists, evolutionary biologists and mathematical modellers have shown for the first time how rates of island colonisation, natural extinction, and species formation vary with island size and distance from the continent. MORE
Header image: Mascarene paradise-flycatcher. Credit: Christophe Thebaud.