Question

Even after piercing the nostrils of cattle for tying the nasal knot for several generations,the newborn calves are to be pierced again.
(a) Can you relate this statement to any idea in the history of evolution?
(b) Examine the status of this theory in the history of evolution.
(c) Examine the reason for this theory becoming rejected or outdated.

Answer 1

(a) The statement can be related to Lamarck's theory of inheritance of acquired characters.

(b) The scientist Jean Baptist Lamarck formulated this theory of inheritance of acquired characters. According to the theory, use or disuse of organs depending on living conditions leads to change in the structure or loss of organs. This change in the structure of organs is transmitted to the next generation and then, new species evolve with new structure of organs. For example:

1) Due to continuous stretching the neck, giraffes with long necks evolved.

2) Ancestors of snake had limbs but their disuse led to evolution of snakes without limbs.

(c) The changes that occur in the body of an organism do not always affect the structure of genes. For example- Children born to mothers with pierced ears do not have pierced ears when they are born. Hence this theory was rejected or is considered outdated.