Formation of new species from an ancestral species is called as speciation. When the number of animals get increased in a habitat, they migrate to new habitats. They get divided into small groups and develop reproductions isolation. Such animals either lost or get adapted by developing variations. Gradually, the gene pool become different than the ancestral species and lead to the formation of new species.
The speciation is of two types
(A) Allopatric speciation :
It occurs when members of a species behave their own habitat and migrate to distantly situated new habitats. Gradually, there gene pool is changed because of new habitat and they develop
distinctly new characteristics and lead to the formation of new species. It is also called as geographical speciation. Example: Darwin Finches.
(B) Sympatric speciation :
When a new species evolved from a single ancestral species while inhabiting the same geographic region.
Sometimes two genetically variable animals or animals from different habitat may interbreed to form an new species. This process occurs between the animals of different species. It is called as hybridization and resulting offspring is called hybrid.
The main factors of speciation are as follows :
- Mutation
- Genetic drift
- Migration
- Natural selection
- Sexual-Recombination
- Hybridization
- Isolation