Question

"The genetic variations appearing among the members of a population bring about evolution". This statement defines

• A. Mutation theory
• B. Lamarckism
• C. Darwinism
• D. Neo-Darwinism

Answer 1

The correct option is A Mutation theory

a) Mutation theory was proposed by Hugo de Vries. He proposed that the new species arise not by the accumulation of minor and continuous variations by natural selection but by suddenly appearing saltatory variations for which he coined the term mutation. The mutation is any heritable change in the genetic makeup of an individual.

b) Lamarck explained the mechanism of evolution on the basis of the use and disuse of organs. His theory is also known as the theory of inheritance of acquired characters according to which the characters which are acquired during the lifetime of an organism are transferred to the offspring. This is known as lamarckism.

c) Darwin proposed the theory of natural selection according to which the organisms with favourable variations would survive because they are fittest to face their surroundings while the organisms which are unfit for surrounding variations are destroyed naturally. This is known as darwinism.

d) The theory of evolution as proposed by Darwin has been modified in the light of modern evidence from genetics, molecular biology, palantaeology, ecology and is known as neo-darwinism. It may be defined as the theory of organic evolution by the natural selection of inherited characteristics.

So, the correct answer is 'Mutation'.