Allopatric speciation

Definition

Allopatric speciation occurs when a population is geographically separated into two groups that evolve independently. Over time, genetic differences accumulate, leading to the formation of distinct species.

5 Must Know Facts For Your Next Test

1. Geographic isolation is the primary driver of allopatric speciation.
2. Allopatric speciation can result from natural barriers such as mountains, rivers, or human activities like urban development.
3. Over time, isolated populations undergo genetic divergence due to mutation, natural selection, and genetic drift.
4. Reproductive isolation eventually develops between the separated populations, preventing interbreeding if they come into contact again.
5. Examples include Darwin's finches on the Galapagos Islands, which evolved from a common ancestor into multiple species due to geographic separation.

Review Questions

• What role does geographic isolation play in allopatric speciation?
• How do genetic differences accumulate in isolated populations during allopatric speciation?
• Can you provide an example of a species that has undergone allopatric speciation?

Related terms

Sympatric Speciation: Speciation occurring within a shared habitat without geographic separation.

Reproductive Isolation: Mechanisms that prevent different species from interbreeding and producing fertile offspring.

Genetic Drift: Random changes in allele frequencies in a population, often having significant effects in small populations.