EVIDENCE IN FAVOUR OF THE MUTATION THOERY -

Mutation theory can explain both progressive and retrogressive evolution and the occurrence of both changed and unchanged forms.

Example of Mutation

1. Ancon sheep is a short lagged variety, which appear suddenly.

2. Development of hornless cattle from homed cattle.

3. Hairless cats and double toed cats have developed through mutations.

4. Development of delicious Apple, Noval orange, Red sunflower.

EVIDENCES AGAINST THE MUTATION THEORY -

1.       The mutation are rare occurrence. Hence it is doubtful all new character shown by animals and plants could appear by mutation.

2.       Evening Primrose of de Vries was not a normal plant but a complex heterozygous form with chromosome aberrations.

3.       Mutations are mainly retrogressive or negative.

4.       Mutations are generally recessive while traits taking part in evolution are usually dominant.

5.       Mutation theory can't explain the development of mimicry, mutual dependence of flowers and pollinating insects.

6.       Mutation theory does not explain the role of nature.