The key difference between parapatric and sympatric speciation is that parapatric speciation is the process where new species are formed from a continuously distributed population, while sympatric speciation is the process where new species are formed within the range of the ancestral population.
Speciation takes place when a group within a species separates from other members and develops its own unique features. Therefore, speciation is the creation of a new species from an existing species. This derives a new species from one or different ancestors. The objective of speciation is to develop a new species with the help of nature. However, this theory changes due to strong needs and the driving force of individuals or creatures. Depending on the process and the driving force, speciation is divided into categories such as allopatric, peripatric, parapatric, and sympatric speciation.
CONTENTS
1. Overview and Key Difference
2. What is Parapatric Speciation
3. What is Sympatric Speciation
4. Similarities – Parapatric and Sympatric Speciation
5. Parapatric vs Sympatric Speciation in Tabular Form
6. Summary – Parapatric vs Sympatric Speciation
What is Parapatric Speciation?
Parapatric speciation happens when a species is spread out in a large geographical area but reproduces with local species, giving rise to a new species. It is a process where two or more new species derive from an existing ancestor. There are three main features in this speciation: mating takes place in a non-random manner, unequal gene flow, and population exist in continuous or discontinuous geographic ranges. Although the individuals are able to mate with each other, they cannot randomly mate with any individual within the same group. Moreover, the gene flow of ancestors remains as it is and continues without stopping in any subgroup of the species. A barrier is not created in parapatric speciation, and this does not completely separate the groups within species. The distribution pattern of the speciation is a result of incomplete geographical barriers, unequal dispersal, or divergent expressions of behavior within individuals.
Figure 01: Parapatric Speciation
Natural selection is known as the primary driver in parapatric speciation. The selection strength during divergence is considered an important factor. This type of speciation also results from reproductive isolation due to social selection.
What is Sympatric Speciation?
Sympatric speciation happens when a new species evolve from a single ancestral species while inhabiting the same geographical region. It is considered a traditional geographic mode of speciation. This type of speciation commonly takes place in plants that are prone to multiple homologous sets of chromosomes, resulting in polyploidy. Sympatric speciation does not need a large geographical distance in order to reduce the gene flow between the parts of the population.
Figure 02: Sympatric Speciation
Speciation takes place when there is no barrier to prevent the members of a species from mating, and all members of the species are found in close proximity to one another. An example of sympatric speciation is an insect known as an apple maggot that lays eggs inside the fruit of an apple, which eventually causes it to rot.
What are the Similarities Between Parapatric and Sympatric Speciation?
- Parapatric and sympatric speciation creates new species.
- Both do not take place through geographic isolation.
- Both have effects on population barriers.
- Groups from the same ancestral population evolve into species.
What is the Difference Between Parapatric and Sympatric Speciation?
Parapatric speciation is a process where new species are formed from a continuously distributed population, while sympatric speciation is a process where new species are formed within the range of the ancestral population. Thus, this is the key difference between parapatric and sympatric speciation. In parapatric speciation, formation takes place when they separate from the population, while in sympatric speciation, formation takes place within the same habitat. Moreover, gene flow takes place between population barriers in parapatric speciation, whereas gene flow diminishes due to polyploidy in sympatric populations.
The below infographic presents the differences between parapatric and sympatric speciation in tabular form for side-by-side comparison.
Summary – Parapatric vs Sympatric Speciation
Parapatric and sympatric speciation are two types of speciation that create new species from existing species. Parapatric speciation is a process where new species are formed from a continuously distributed population. Parapatric speciation occurs when a species is spread over a wide geographical area but only reproduces with local species and results in the development of a new species. In sympatric speciation, new species are formed within the range of the ancestral population. It takes place when there is no physical barrier to prevent any members of species from mating with one another, and all members are in close proximity. The gene flow of parapatric speciation takes place between population barriers; however, in sympatric speciation, the gene flow diminishes due to factors such as polyploidy, differentiated habitats, and sexual selection. So, this summarizes the difference between parapatric and sympatric speciation.
Reference:
1. “Parapatric Speciation – Definition, Properties, Mechanism & Importance.” GeeksforGeeks.
2. “Speciation.” National Geographic Society.
3. “Sympatric Speciation – Understanding Evolution.” Understanding Evolution – Your One-Stop Source for Information on Evolution.
Image Courtesy:
1. “Parapatric Speciation Schematic” By Andrew Z. Colvin – Own work (CC BY-SA 4.0) via Commons Wikimedia
2. “Sympatric Speciation Schematic” By Andrew Z. Colvin – Own work (CC BY-SA 4.0) via Commons Wikimedia
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