Final answer:
The island biogeographic theory, developed by MacArthur and Wilson, posits that the number of species on an island reflects a dynamic balance between immigration and extinction rates, influenced by island size, isolation, and habitat diversity.
Step-by-step explanation:
The island biogeographic theory suggests a framework for understanding the various factors that influence the diversity of species found on islands. This theory, formulated by Robert H. MacArthur and Edward O. Wilson in 1967, proposes that the number of species on an island is determined by a balance between species immigration and extinction rates. Notably, this equilibrium is influenced by factors such as the island's size, isolation, and the geographical diversity that provide niches for speciation.
Islands further from the mainland have lower immigration rates and therefore a lower equilibrium number of species, while smaller islands tend to have higher extinction rates due to smaller population sizes and less habitat diversity. This theory has since been applied to habitat fragments in landscape ecology, treating them as 'islands' in a 'sea' of developed land. The concept has been instrumental in the study of preserve designs for maintaining biodiversity.