The process by which a new species develops from the existing species is known as speciation.
Factors that affect the process of speciation are:
Geographical isolation – Caused by various types of barriers such as mountain ranges, rivers and seas. Leads to reproductive isolation due to which there is no flow of genes between separated groups of population.
Genetic drift – It is the random change in the frequency of alleles in a population over successive generations. Generic drift takes place due to severe changes in DNA or change in number of chromosomes.
Natural selection –Process of selection of characteristics which contributes to the fitness of survival of organisms. Genetic variation within a population of organisms may cause some individuals to survive and reproduce more successfully than others.
Gene flow- occurs between population that are partly but not completely separated.