2.3 Theory of Island Biogeography

Theory of Island Biogeography

study of ecological relationships and community structure on islands (doesn’t have to be an island : ex.central park)

Two basic Rules

• Larger the island = more total species it can support (ecosy. diversity = more food = more richness)

• Islands closer to mainland support more species - easier for colonizing org. to get to island = more genetic diversity in the new population

Distance to Mainland

inverse relationship b/w island distance from mainland and species richness

• further away from mainland, the fewer the species.

Evolution of Islands

Islands have limited space and resources, creating unique conditions from evolution

• more pressure for species to adapt to narrower riches

Adaptive Radiation

a single species radically evolves into several new species to use different resources and reduce competition

Ex. galapagos finches - beak evolved for different food sources

endemic

species can only be found/survive in 1 specific place