(N/A) Lamarck,in his book 'Philosophic Zoologique' $(1809)$,proposed that the evolution of life forms occurred due to the use and disuse of organs.
$\Rightarrow$ He provided the example of giraffes,which initially did not have long necks.
- Due to the scarcity of surface vegetation,they had to stretch their necks to reach the leaves on tall trees.
- Consequently,they adapted to this situation through the elongation of their necks.
- By passing this acquired character to succeeding generations over many years,they eventually acquired long necks.
- This theory,also known as Lamarckism,is no longer accepted today.
- August Weismann offered the greatest opposition to this theory of inheritance of acquired characters and proposed his theory of continuity of germplasm in $1892$.