Question

Describe how an island’s size and distance from the mainland affect the island’s species rich.

Short answer

The island, which is near to the mainland, shows more species richness than the isolated islands. The migration of the species from islands to the mainland or vice versa declines if the island is far from the mainland, resulting in fewer species in islands.

Step-by-step solution

Speciation

The evolutionary process in which various circumstances give rise to the formation of new organisms is called speciation. Genetic drift, the force of natural selection, gene flow, migration, and changes in geographical regions are some of the causes of speciation. Speciation leads to biodiversity in the ecosystem.

Species diversity

An ecosystem is said to be diversified when it includes the various number of species in a community. The variation present in the community is called species diversity. Evolution is the major cause of species diversity. The ecosystem, which has the most diversified species community, is called biodiversity hotspots.

Factors affecting the species diversity in islands 

The island, which is near to the mainland, allows the migration of the species. It leads to interbreeding and the formation of new species. In another way, migrated species might adapt to the islands differently.The important factor which leads to species diversity in islands near the mainland is constant gene flow.

Therefore, an island that is isolated or located far from the mainland does not show much species diversity due to the absence of constant gene flow. The organisms which migrate to the isolated islands might become extinct due to genetic drift.