What is the Difference Between Allopatric and Peripatric Speciation

The key difference between allopatric and peripatric speciation is that allopatric speciation occurs when populations become isolated geographically from each other so that they cannot interbreed among each other, while peripatric speciation occurs when the species spread over a larger area, facilitating interbreeding of members in the group.

Speciation is the creation of a new kind of plant or animal species. This process takes place when a group within a species separates from other members and develops unique features and characteristics. There are four major variants of natural speciation. They are allopatric, peripatric, parapatric, and sympatric. Speciation can also be induced artificially through animal husbandry, laboratory experiments, and also agriculture. Genetic drift is a major contributor to speciation.

CONTENTS

1. Overview and Key Difference
2. What is Allopatric Speciation
3. What is Peripatric Speciation
4. Similarities – Allopatric and Peripatric Speciation
5. Allopatric vs Peripatric Speciation in Tabular Form
6. Summary – Allopatric vs Peripatric Speciation

What is Allopatric Speciation?

Allopatric speciation is a mode of speciation that occurs when populations become geographically isolated from each other. Various geographic changes such as movements of continents and formation of mountains, water bodies, glaciers, and islands, as well as changes due to agricultural and developmental activity by humans, affect the distribution of species populations, separating the species population separation into isolated subpopulations. Allopatric speciation does not facilitate the interbreeding between the members of the group. This usually occurs between biological populations to an extent where it prevents or interferes with gene flow. Allopatric speciation is also known as geographic speciation or vicariant speciation.

Vicariant populations undergo genetic changes when they go through selective pressures, accumulate different mutations, and experience genetic drifts. Reproductive isolation is considered the primary mechanism that drives genetic divergence allopatric speciation. The most common mechanisms of allopatric speciation are pre-zygotic and post-zygotic isolation. However, determining which form evolves first is difficult. Pre-zygotic is the presence of a barrier before an act of fertilization, while post-zygotic is the prevention of inter-population successfully after fertilization.

What is Peripatric Speciation?

Peripatric speciation is a mode of speciation where the species spread over a larger area, facilitating the interbreeding of members in the group. If small populations of species are isolated, selection acts on the population regardless of the parent population.

Peripatric speciation is distinguished using three important features: the size of the population that is isolated, string selection imposed by the dispersal, and colonization to new environments and its potential effects of genetic drifts towards small populations. The size of the isolated population is an important factor since individuals colonize new habitats that have only a small sample of genetic variation of the original population. There, divergence takes place due to strong selective pressures. This leads to the rapid fixation of alleles within populations. This also leads to potential genetic incompatibilities during evolution. Such incompatibilities cause reproductive isolation and give rise to rapid speciation events.

Peripatric speciation is mostly supported by species distribution in nature. The strongest evidence for the occurrence of peripatric speciation is oceanic islands and archipelagos.

What are the Similarities Between Allopatric and Peripatric Speciation?

• Allopatric and peripatric speciations are based on geographic isolations.
• They are natural types of speciation.
• Both are based on natural selection.
• The speed of emergence of new species is slow in both allopatric and peripatric speciation.

What is the Difference Between Allopatric and Peripatric Speciation?

Allopatric speciation is the phenomenon where populations are not allowed to interbreed with each other, while peripatric speciation is the phenomenon where populations are allowed to interbreed with each other. This is the key difference between allopatric and peripatric speciation. A group in allopatric speciation is bigger than a group in peripatric speciation. Allopatric speciation occurs between biological populations; therefore, it is dependent. Peripatric speciation, on the other hand, acts on a population independent of the parent population.

The below infographic presents the differences between allopatric and peripatric speciation in tabular form for side by side comparison.

Summary – Allopatric vs Peripatric Speciation

Allopatric and peripatric are two major speciation types. Allopatric speciation is a mode of speciation that occurs when populations become isolated geographically from each other. This usually occurs between biological populations. Peripatric speciation is a mode of speciation when new species are formed from an isolated peripheral population. The key difference between allopatric and peripatric speciation is interbreeding. Allopatric speciation is the phenomenon where populations are not allowed to interbreed with each other, while peripatric speciation is the phenomenon where populations are allowed to interbreed with each other.

Reference:

1. “Speciation.” National Geographic Society.
2. “Peripatric Speciation.” Biology Articles, Tutorials & Dictionary Online.

Image Courtesy:

1. “Peripatric Speciation” By Chiswick Chap – Own work (CC BY-SA 4.0) via Commons Wikimedia
2. “Allopatric speciation caused by topography” By Andrew Z. Colvin – Own work (CC BY-SA 4.0) via Commons Wikimedia