Question

Explain the theory of giraffe’s necks according to Lamarck theory of evolution.

Answer 1

Hint: Jean Baptise Lamarck put forward the theory of Lamarckism which is based on use and disuse of organs is passed on to the offsprings for successive generations. This theory is also known as inheritance of acquired characters.

Complete answer:
To answer this question, we must know about Lamarck's theory of evolution.
French naturalists put forward the theory which states that the physical characteristics that a parent has acquired due to use and disuse can pass on to the off springs generation after generation. Hi theory is also known as theory of acquired characters.

The acquired characters mean the characteristics which are controlled by the change in environment. The organisms adapt themselves with the change in the environment by adapting new habits or change in the physical form. He explained this theory by giving the example of a giraffe.

He said that giraffes had normal neck and normal forelimbs. As the food from the ground started to decrease, the giraffe started stretching its neck and forelimbs in order to reach the higher branches. This led to the long neck of the giraffe. These acquired characteristics passed on to the generations and subsequently the giraffes gained its long neck.

Note: Lamarck was the first one to put forward the theory of evolution. His theory of acquired characters is the basis of the modern theory of evolution. Darwin was inspired by Lamarck's theory and put forward the theory of natural selection and survival of the fittest.