E.O. Wilson's theory of island biogeography identifies three main pressures that influence biodiversity on islands:
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Area Effect: This refers to the size of the island. Larger islands tend to support more species than smaller ones because they have a greater variety of habitats and resources, as well as a lower likelihood of extinction for populations.
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Distance Effect: This pressure relates to the distance of the island from the mainland or other sources of colonizing species. Islands that are closer to the mainland generally have higher species richness since it's easier for species to migrate to these islands. Conversely, more distant islands tend to have fewer species due to the challenges of colonization.
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Immigration and Extinction Rates: The interplay between immigration (the arrival of new species) and extinction (the loss of species) is central to Wilson's theory. The rates of these processes are influenced by factors such as island size and distance, leading to a dynamic balance that establishes the island's overall level of biodiversity.
Together, these pressures help to explain the patterns of species richness observed on islands and are key components of Wilson's broader ecological research.
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