Question

How evolution related to natural selection revealed by the imperfection of living organisms

Answer 1

In the course of evolution natural selection is the fundamental driving force. Natural selection is link between the changes in the environment and genetic variations of species effort to survive and reproduce. Natural selection encourages those organisms having the favorable genes to survive in that particular environment.

For example 'Industrial melanism' in Great Britain

Earlier light colored paper moths Biston betularia are high in number. These nocturnal paper moth during day time rest on the tree trunk. Pale body color moths are camouflaged well on the lichen covered tree trunk. They get protected from the predator birds. The dark colored moths are developed due to random mutation. These black moths are Biston carbonaria, resting on the lichen covered tree trunks were easily detected by the predatory birds. Hence black color moths are rare.

After industrial revolution, lichens killed due to the black sooty smoke. Tree trunks are turn black in color due to the deposition of the black sooty smoke. Now black paper moths are getting the advantage of the camouflaged on the black tree trunks and their population is increased. On the other hand the pale paper moths become easily identified on the black tree trunk. Predatory birds can easily detect the pale paper moth and their population drastically reduced.     

Hence natural selection remove the imperfect organism from the environment. In this case, pale paper moth is imperfect after the industrialization.