Explain the terms
(i) Speciation (ii) Natural selection

Explanation

a) i) Speciation : Speciation is the evolution of reproduction isolation among once interbreeding population i.e, the development of one or more species from an existing species.
ii) Natural selection : Natural relationship in the process, according to Darwin, which bring about the evolution of new species of animals and parents.
b) Four factors which can lead to speciation are :
Genetic drift : Over generation, genetic drift may accumulate which lead to speciation.
Natural selection : Natural selection which may give rise to speciation.
Severe DNA change
A variation may occur which does not allow sexual act between two groups.