Although we may first think of oceanic islands, any other isolated area can exist as an island, e.g., mountain tops, or patches of once contiguous land cover. The coined the term dynamic equillibrim meaning the rates of immigration and extinction achieve a dynamic balance as opposed to static composition of species on islands. A equals area, c is a fitted constant, and z is another fitted parameter that equals slope when plotted. In theory, larger islands contain more habitat and most likely a larger variety of habitat thus equalling more species, i.e., greater diversity. Large islands close to the mainland would have the greatest number of species.
Fewer species are on islands far from the mainland or other continental source.
Therefore, a small island far away would have the fewest number of species. Colonization and extinction cause a continual turnover of species on islands. New species arrive and out compete existing species that then go extinct, however, dynamic equillibrium keeps the number of species relatively constant. The monograph published in 1967 by MacArthur and Wilson, The Theory of Island Biogeography is a seminal work in biogeography but not without criticism. Although some early studies supported their notion, other later works disputed the theory as too simplistic.