| Mechanism | Definition and Examples |
| Adaptive radiation | The process of evolution of different species in a given geographical area starting from a point and literally radiating to other areas of geography (habitats) is called adaptive radiation. Example: Darwin finches |
| Divergent evolution | The structures in different organisms which have similarities in their anatomy or basic plan but serve different functions are known as homologous structures. This is an example of divergent evolution. Example: Bones of forelimbs in man and whale |
| Convergent evolution | The structures in different organisms which are not similar anatomically though they perform similar functions are called analogous organs. This is an example of convergent evolution. Example: Wings of butterfly and bird |
| Evolution by anthropogenic action | Herbicide and pesticide resistance developed in the weeds and pests respectively after prolonged use of herbicides and pesticides. This is also an example of natural selection which supports the process of evolution due to anthropogenic action or due to actions of man. |