Explain in detail palaeontology evidences and …

Evidences of evolution: Some of the important sources which provide evidences for evolution are: (a) Analogous Organs: Organs which performs similar function but are different in structure and origin. Example - wings of a bird and wings of an insect. The presence of analogous organs indicates that even the organisms having organs with different structures can adapt to perform similar functions for their survival under hostile environmental conditions. Thus, the presence of analogous organs in different animals provide evidence for evolution by telling us that though they are not derived from common ancestors, they can still evolve to perform similar functions to survive, flourish and keep on evolving in the prevailing environment. (b) Homologous Organ: Organs which have different functions but similar structure and origin. Example - fore arm of frog, lizard, bird and human. The presence of homologous organs in different animals provides evidence for evolution by telling us that they are derived from the same ancestor who had the 'basic design' of the organ on which all the homologous organs are based. (c) Fossils: The remains of dead animals or plants that lived in the remote past are known as fossils. The fossils provide evidence of evolution. For example, a fossil bird called Archaeopteryx looks like a bird but it has many features which are found in reptiles. This is because Archaeopteryx has feathered wings like those of birds but teeth and tail like those of reptiles. Therefore, Archaeopteryx is a connecting link between the reptiles and birds and suggests that birds have evolved from reptiles. Thus, fossils provide evidence that the present plants and animals have originated from the previously existing ones through the process of continuous evolution.