Question

Differentiate between: Allopatric and sympatric speciation.

Answer 1

Hint: The speciation is the process of the formation of new species from the existing one. The new species cannot mate with the old species in this process.

Complete answer:
A species is a large group of organisms which shares genetic heritage and can interbreed to create the offspring typically by sexual reproduction.
Speciation are of two major types: -
> Allopatric speciation- this mode occurs when the biological population is isolated with each other to prevent the gene flow. Allopatric speciation is divided into two sub-categories as follows-
> Parapatric speciation - Allopatric speciation in which the species are not formed by any physical barrier. In Parapatric speciation individuals can interbreed.
> Peripatric speciation - Allopatric speciation in which new species are formed from an isolated peripheral population. In the Peripatric speciation population are prevented from exchanging genes.
Sympatric speciation- this mode occurs when a new species lives with the ancestral species in the same region.
The main differences between allopatric and sympatric speciation are as follows: -

S.No.	Allopatric Speciation	Sympatric Speciation
1.	Includes physical isolation of population due to extrinsic barrier	It includes the evolution of new species from older one in the same habitat.
2.	It is the product of natural selection.	It is the product of polyploidy.
3.	The formation of new species takes place at a slow rate.	The formation of new species takes place at a fast rate.
4.	It includes geographical isolation like mountains, rivers, etc.	It does not include any geographical isolation
5.	e.g.- Darwin’s finches	e.g.- Polyploidy in tobacco.

Note: The speciation can be the result of genetic drift that involves transfer of variations from one population to another. It can also be achieved by genetic drift i.e. the random change in allelic frequencies.