The evolutionary idea contributed proposed by Charles Darwin called ‘Darwinism’ or Natural selection theory, explaining the mechanism of evolution is clearly stated in his book ‘ Origin of species’.
The important postulates of the theory are: Over production, Struggle for existence, Variations, Survival of the fittest, and Origin of species.
Lamarckism is popularly known as theory of inheritance of acquired characters or theory of use and disuse organs.
Darwinism vs Lamarckism
Darwinism
1. It does not believe in the internal vital force.
2. They do not form part of Darwin’s natural selection theory.
3. An organ can develop further or degenerate only due to continuous variations.
4. Struggle for existence is very important in this theory.
5. Only useful variations are transferred to the next generation.
6. Darwin’s natural selection theory is based on survival of the fittest.
Lamarckism:
1. This theory states that there is an internal vital force in all organisms.
2. It considers new needs or desire produce new structures and change habits of the organism.
3. According to this theory if an organ is constantly used it would be better developed whereas disuse of organ results in its degeneration.
4. It does not consider struggle for existence.
5. All the acquired characters are inherited to the next generation.
6. Lamarckism does not believe in survival of the fittest.
