Lamarckism short note
Ans :
i) Lamarckism is the hypothesis that an organism can pass on characteristics that it has acquired during its lifetime to its offspring.
ii) It is also known as the inheritance of acquired characteristics or soft inheritance.
iii) Jean-Baptiste Lamarck proposed that morphological changes occurring in living organisms are responsible for evolution and the reason behind those morphological changes is activities or laziness of that organism.
iv) He called this concept as principle of 'use or disuse of organs'.
v) The neck of giraffe has become too long due to browsing o leaves of tall plants by extending their neck for several generations; similarly, shoulders of the ironsmith have become very strong due to frequent hammering movements.
vi) Wings of birds like ostrich and emu have become weak due to no use.
vii) Legs of the birds like swan and duck have become useful for swimming due to living in water and snake have lost their legs by modifications in their body for burrowing habit.
viii) All these examples are types of 'acquired characters' and are transferred from one to another generation. This is called as theory of inheritance of acquired characters or Lamarckism.