Island biogeography is a field within biogeography that attempts to establish and explain the factors that affect the species richness of natural communities. The theory was developed to explain species richness of actual islands. It has since been extended to mountains surrounded by deserts, lakes surrounded by dry land, fragmented forest and even natural habitats surrounded by human-altered landscapes. Now it is used in reference to any ecosystem surrounded by unlike ecosystems. The field was started in the 1960s by the ecologists Robert MacArthur and E.O. Wilson, who coined the term theory of island biogeography, as this theory attempted to predict the number of species that would exist on a newly created island.
For biogeographical purposes, an "island" is any area of suitable habitat surrounded by an expanse of unsuitable habitat. While this may be a traditional island—a mass of land surrounded by water—the term may also be applied to many untraditional "islands", such as the peaks of mountains, isolated springs in the desert, or expanses of grassland surrounded by highways or housing tracts. Additionally, what is an island for one organism may not be an island for another: some organisms located on mountaintops... Read More