Island biogeography is the
study of the species composition and species richness on islands. The
equilibrium value (equilibrium diversity value) of an island based on the area
of the island- the larger the area the more resources there are on the island.
Smaller islands support smaller populations, and smaller populations are more expected
to turn into wiped out. Here is where theTarget Effect comes in play. The Target Effect says
that larger islands have higher migration rates as they are a larger target.
Islands have less varied populations than large continents, particularly those
far from mainland. Such islands have less opportunity for colonization.