Allopatric speciation

Allopatric speciation is a mode of speciation that occurs when biological populations of the same species become isolated from each other to an extent that prevents or interferes with genetic interchange. This geographical isolation can lead to the evolution of species that are distinct from each other.

Overview

Allopatric speciation is a key concept in the field of evolutionary biology. It is one of the main models of speciation and has been most extensively studied in the context of island biogeography. The term "allopatric" is derived from the Greek allos (meaning "other") and patra (meaning "fatherland").

Process

The process of allopatric speciation involves three main stages: isolation, divergence, and reproductive isolation.

Isolation

The first stage of allopatric speciation is the physical separation of populations. This can occur due to various geographical changes such as mountain formation, island formation, or habitat loss. The separated populations are then prevented from interbreeding due to the physical barriers.

Divergence

Once isolated, the populations begin to diverge due to natural selection, genetic drift, and mutation. These processes lead to the development of differences in traits and behaviors between the populations.

Reproductive Isolation

Over time, these differences accumulate to the point where members of the different populations can no longer interbreed, leading to reproductive isolation. This marks the final stage of allopatric speciation, with the formation of two distinct species.

Examples

One of the most famous examples of allopatric speciation is the Darwin's finches on the Galapagos Islands. Each island has its own distinct species of finch, which evolved from a common ancestor after becoming geographically isolated from each other.

See also

• Sympatric speciation
• Peripatric speciation
• Parapatric speciation
• Adaptive radiation