Allopatric speciation

Definition

Allopatric speciation occurs when a population is divided by a geographical barrier, leading to reproductive isolation and the formation of new species. Over time, genetic differences accumulate making interbreeding between the separated populations impossible even if they come back into contact.

5 Must Know Facts For Your Next Test

1. Geographical barriers such as mountains, rivers, or distance can lead to allopatric speciation.
2. Genetic drift and natural selection act on separated populations differently, causing them to evolve independently.
3. Reproductive isolation is a key component in allopatric speciation as it prevents gene flow between the populations.
4. Allopatric speciation can result in two or more distinct species from an original population.
5. Examples of allopatric speciation include Darwin's finches on the Galápagos Islands.

Review Questions

• What role do geographical barriers play in allopatric speciation?
• How does reproductive isolation contribute to the process of allopatric speciation?
• Can you provide an example of allopatric speciation from nature?

Related terms

Sympatric Speciation: Speciation that occurs without geographical separation within the same environment.

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

Genetic Drift: A mechanism of evolution that causes random changes in allele frequencies in a population.