Write a short note on Neo-Darwinism.

Explanation

It was proposed by Fischer, Sewall Wright, Mayr. According to this theory, five basic. factors are involved in the process of Organic evolution. They are:
1. Gene mutations , 2. Chromosomal mutations
3. Genetic recombinations. 4. Natural, selection
5: Reproductive isolation.
1. Gene mutations : Heritable changes in the structure of a gene. are called gene mutations or point mutations. They alter the phenotypic character of the individuals. Thus, gene mutations tend to produce Variations in the offspring.
2. Chromosomal mutations : Heritable changes in.the structure of chromosomes called chromosomal mutations. They also bring about variations in the phenotype of organism which lead to the occurrence of variations in the off spring.
3. Genetic recombinations : Recombinations of genes due to crossing. over during meiosis are responsible for bringing genetic variability, among the individuals of the same species.
4. Natural selection : .Natural selection does not produce any genetic changes, but it favours some genetic change while rejecting others. .
5. Reproductive isolation: The absence of gene exchange between popụlation is called the reproductive isolation. It plays a great role in giving rise to new species and preserving the species integrity.