Main differences between the theories of Lamarck and Darwin —
| Lamarck's Theory | Darwin's Theory |
|---|---|
| Known as the theory of inheritance of acquired characters | Known as the theory of natural selection |
| Believes in the use and disuse of an organ. Parts used or changes acquired get transmitted to the next generation. | Believes that since variations exist in individuals, only the fittest survive in the struggle for existence. |
| New species evolve after a long period of time after many generations by acquiring new characters. | New species evolve due to accumulation of favourable variations over a long period of time. |