Speciation: Meaning, Process, Causes, Types, Examples

Speciation is a process in which a new kind of plant or animal species is evolved. The requests of a different environment, as well as the characteristics of the new group's members, will make a distinction between the new species from their ancestors. An example of Speciation is Galapagos Finch. Let's discuss the topic of speciation in detail.

Key Takeaways: Speciation, sympatric speciation, peripatric speciation, Galapagos Finches, hybridization, chromosome mutation, environment, species

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Meaning of Speciation

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Speciation is the evolutionary process by which a new group of organisms is formed from existing species. It is a process that involves genetic differentiation and eventually reproductive isolation. The new species emerged with greater adaptability and efficiency than their previous ancestors. It occurs in two ways:

• Transformation of old species into new species with time.
• Multiplication of species.

The video below explains this:

Speciation Detailed Video Explanation:

Speciation

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Process of Speciation

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Speciation begins with isolation of population through either physical or genetic isolation. After that, some genetic changes will occur which result in different species of subpopulations and they will diverge by mutation, selection, and genetic drift over some time. This process becomes so high which would form hybrids between the population.

Also Read: Principles of Inheritance and Variation

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Causes of Speciation

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Speciation occurs as a result of several factors, the most important of which are:

Natural Selection

According to Charles Darwin, various individuals within a species may develop distinct characteristics that are beneficial and influence the individual's genetic makeup. These characteristics will be preserved under such conditions, and new species may emerge over time.

Drift in Genetics

Genetic Drift is caused by “Sampling Error” which is a random fluctuation in the frequency of the allele. Genetic Drift does not require speciation. It is actually the process of evolution or change in species from one to another.

Migration

Species acquire within themselves certain characteristics that differ from the original population due to changes in location or migration. It is due to geographical isolation which leads to speciation.

Mutations on the Chromosome

Chromosome mutation contributes to isolating mechanisms and preserving a particularly advantageous gene complement. Such mutation results in the emergence of new species when passed down from generation to generation.

Natural Causes

Natural events forced by the environment, such as a river or a mountain range, may cause the separation of what was once a consistent population into two or fewer populations.

Gene flow restriction

Due to the lack of some external physical barriers, speciation may occur. There could be reduced gene flow across a wide geographical range, with people in the far east having no way of mating with people in the far west.

Also Read: Accumulation of Variation During Reproduction

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Types of Speciation

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Allopatric Speciation

Allopatric speciation occurs when the original population is split in two by a barrier, resulting in reproductive isolation. Mayr presented the model for allopatric speciation. It is a concept in which new species emerge due to physical geographical barriers eventually dividing the larger population into smaller. Darwin’s finches are the examples of allopatric speciation.

Peripatric Speciation

Peripatric speciation is a type of allopatric speciation that occurs when the isolated subpopulation is small in size. Genetic drift is quicker in small populations therefore it is considered as an active member. New species emerge as a result of the interaction of all of these factors. Petroica multicolour are the examples of Peripatric speciation.

Parapatric Speciation

Parapatric speciation is a form of speciation in which the population from a large geographic area mate with the neighbouring ones rather than from a different part of the geographical area. Genetic variation is formed due to the result of lesser gene flow and selection pressures across the population’s range. Anthoxanthum odoratum are the examples of Parapatric speciation.

Sympatric Speciation

Sympatric Speciation is the formation of new species from an original population. The factors contributing to its establishment are different ecological niches, reproductive isolation of the new population. In multicellular organisms or randomly mating populations, a sympatric speciation is thus a sporadic event. Apple maggot flies are the examples of Sympatric speciation.

Also Read:

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Things to Remember

Following are some important points:

• Speciation' or cladogenesis, results from a splitting event in which a parent species is split into two distinct species, often as a result of geographic isolation or another driving force involving population separation.
• Artificial speciation is a type of speciation that can be achieved with the help of human intervention.
• When the two subpopulations are no longer capable of reproducing with each other, even if they are brought back together, speciation is complete.
• The type of speciation that occurs when a portion of an environment is polluted is known as parapatric speciation.
• Mining activities that produce waste containing high levels of metals such as lead and zinc contribute to polluted environments.