Question

List four factors responsible for speciation.

Answer 1

Hint: The process of formation of new and distinct species.

Complete answer:
Speciation is the process of formation of new species through old species through evolution or any other mode of genetic variation.
Factors responsible for speciation are:
The first factor is geographical isolation which includes the natural selection and genetic drift while the second factor is hybridization which includes reproductive isolation.
The four factors are as follows:
- Geographical isolation – the creation of barriers between various groups of species to prevent gene flow between the different populations. These populations then start to evolve as a new species without any resemblance to the previous ones.
- Natural Selection – Due to adaptation in various regions, species undergo evolution resulting in different variations and changes that occur in organisms. Those organisms which are better adapted will be selected naturally and will survive in the future.
- Genetic drift – Variations in the frequency of different genotypes in a small population and preventing gene flow between them. This result is the disappearance of the occurrence of particular changes in genes. These changes are termed as mutation.
- Reproductive isolation – Due to the above factors several changes occur in the populations resulting in large variations among them. This will lead to incompatibility between organisms, thus preventing gene flow between the members and these individuals evolve into different species.

Note: Speciation is of two major types:
- Allopatric Speciation – it occurs due to geographical isolation. It is further of two types – parapatric and peripatric speciation.
- Sympatric Speciation – an evolution of new species from ancestors where both species live in the same geographical region.