2.3: Theory of Island Biogeography

Vocabulary flashcards covering key concepts from Island Biogeography, including island size/distance effects, colonization, genetic diversity, and adaptive radiation with Galapagos examples.

Island Biogeography

The study of ecological relationships and community structure on islands, including actual islands and habitat islands, and how island size and distance from the mainland affect species richness.

Island size effect

Larger islands support greater ecosystem diversity, more niches, larger populations, lower extinction rates, and higher species richness.

Ecosystem diversity

The variety of habitats and ecological roles present on an island, which increases with island size.

Niches

Different ecological roles or functions that species occupy in an ecosystem.

Colonization

Arrival and establishment of species on an island from the mainland, boosting population size and genetic diversity.

Colonization rate

The speed at which new individuals colonize an island; higher when the island is closer to the mainland.

Genetic diversity

Genetic variation within a population; higher when more colonists immigrate and populations are larger.

Species richness

The number of different species present on an island; increases with island size and proximity to the mainland.

Distance to mainland

The distance between an island and the mainland; greater distance generally lowers species richness due to reduced colonization.

Adaptive radiation

Evolutionary process where a single ancestral species rapidly diversifies into multiple species to exploit different resources and reduce competition.

Galapagos Finches

An example of adaptive radiation on the Galapagos Islands; beaks evolved to fit different food sources.

Beak diversity

Variation in beak shapes among Galapagos finches reflecting adaptations to diverse diets.

Habitat islands

Habitats isolated by surrounding altered landscapes (e.g., Central Park) that function as islands in ecological terms.

Extinction rate

The rate at which species disappear from an island; tends to be lower on larger islands.

Population size

The total number of individuals of a species on the island; larger islands support larger populations.