Compare the mechanism of evolution as put forth by Charles Darwin and de Vries.
Darwin’s Theory |
De Vries Theory |
1.The essence of Darwinian theory about evolution is natural selection. Minor variations occurred over a long time which caused evolution. |
1.De Vries believed that it is mutation that causes evolution and not the minor variations that Darwin talk about. |
2. Darwinian variations are small and directional. |
2. de Vries variations were random and directionless. |
3. Evolution for Darwin was gradual. |
3. de Vries believed that mutation caused speciation and hence called it saltation (single step large mutation) |