1. | This theory was proposed by Alfred Wallace. |
2. | Variations are small directional changes. |
3. | Single-step large mutation is a cause of speciation. |
4. | Large differences due to mutations arise gradually in a population. |
Variations caused by mutation, as proposed by Hugo de Vries, are:
1. | small and directionless | 2. | random and directional |
3. | random and directionless | 4. | small and directional |