Speciation is the process of the formation of a new species from the same parent species in a different environment. The process of speciation may be influenced by many factors like Mutation, Hybridization, Recombination, Isolation, etc. Many new species of animals are the result of speciation.
Speciation helps study and understand the evolution of animals.

The biologist Orator Fuller Cook coined the term speciation in 1906.

Definition

The formation of a new species from a parent species is Speciation.

Types of Speciation

There are mainly two types of speciation which are further divided into subtypes –

(1) Phyletic or Autogenous Speciation
(2) True Speciation

(1) Phyletic or Autogenous Speciation  –

Phyletic speciation is a gradual transformation of species A into another species B by slow changes in the gene pool. The changes in the gene pool could be the reason for environmental adaptation for a long time.

Phyletic speciation is a process of gradual changes in a population. in phyletic speciation, species A changes into species B, and B change into C. This process isn’t quick it takes a lot of time. Phyletic speciation was purposed for the evolution of horses and humans.

Phyletic speciation is also divided into two types – (i) Autogenous transformation  (ii) Allogenous transformation

(i) Autogenous transformation – in this type of transformation one species is transferred into a new species by mutation, natural selection, & genetic drift, etc.

(ii) Allogenous transformation – this is hybridization transformation because a species transforms into another species by mating with another species.

(2) True speciation

True speciation is the origin of two or more species from a single parent species by splitting the parental gene pool.
There are two types of true speciation –
(I) Sudden or Quantum speciation
(II) Gradual speciation

(I) Sudden or Quantum speciation –

this type of speciation occurs suddenly. The sudden speciation occurs because of chromosomal rearrangement or change in chromosomal number (Polyploidy,  autopolyploidy, & amphidiploidy).

(II) Gradual speciation –

A new species develop gradually by accumulation of genetic divergence and reproductive isolation. This process takes a long time and gradual speciation is influenced by natural selection.
There are five types of gradual speciation –
(a) Allopatric
(b) Parapatrc
(c) Peripatric
(d)Sympatric

(a) Allopatric speciation – In this speciation, a species is physically separate from a population. This is also known as geographic speciation because species travel or move to a new geographic area and because of the geographic area they adopt themself according to the place. By visiting a new place traveling species is exposed to many natural forces like mutation, natural selection, genetic drift, and random matting and because of this exposure, a new species is formed.

Example – the blue – gray species pupfish inhabit warm spring of Nevada, California. Aprox 50,000 years ago due to heavy ran the population seprated in two part. One part of population stuck in the same warm spring area and a larger part of population distrituted in different areas. This geographic isolation resulted in two species of pupfish.

(b) Parapatrc – In parapatric speciation, two subpopulations of a species evolve reproductive isolation from one another while continuing to exchange genes.

Example – Greenbut: The bird, little greenbu 1 (Andropadus virens) lives in Tropical rain forests of Cameroon, West Africa . It also lives in neighbouring grass land. The border area where forests and grassland meet, is called ecotone. The birds living in these two habitats are quite different in their beak, legs, body size and body weight.

(c) Peripatric – Peripatric speciation is the formation of a new species peripatric population that buds off from the periphery of a parental population. In 1982, Mayr described the founder effect as peripatric speciation.

Example – The chestnut-tailed antbird (Sciaphylax hemimelaena) is located within the Noel Kempff Mercado National Park (Serrania de Huanchaca) in Bolivia. Within this region exists a forest fragment estimated to have been isolated for 1000–3000 years. The population of S. hemimelaena antbirds that reside in the isolated patch express significant song divergence; thought to be an “early step” in the process of peripatric speciation. Further, peripheral isolation “may partly explain the dramatic diversification of suboscines in Amazonia”.

(d)Sympatric – In sympatric speciation a new species form because of biological barriers in a random matting population that live in the same geographical area.

Example – The Midas cichlid (species of Amphilophus), which is living in Lake Apoyo (a volcanic lake in Nicaragua), is an example of sympathetic speciation. Scientists analyze their appearance, nature, and DNA. Although these two have similarities they are different as well and cannot cross-breed. All the available evidence indicates that one species evolved from another. The newer species of this population has evolved almost recently but if we talk about the terms of evolution, it evolved almost 10,000 years back.

Factors influence speciation

1. Environmental Changes:- climate changes are a regular phenomenon but sometimes climate change makes geographical and ecological for a population and this type of physical barrier influences the formation of a new species.
2. Species richness:- the higher number of species results in more number in mating and a higher mating rate indicates more chances of hybrid species.
3. Dispersal:- the dispersal of animals introduce a new geographic environment to animal and after many years it can result in the formation of new species.
4. Sexual selection:- high number of sexual selection is the result of more chances of speciation.

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