Connecting Link

The living animals which possess the characteristics of two different groups of animals are known as connecting links. For example, Lung fish: – Lungfish possesses the characters of both the fishes and amphibians. It resembles the fishes in having paired fins,...

Atavism

It is the reappearance of a certain ancestral, not parental organs which has either been completely disappeared or reduced. Atavism also gives evidence of organic evolution. The best example of atavism is the presence of a short tail in some human babies. Other than...

Vestigial Organs

The organs which occur in reduced form and are useless to the possessor but were fully developed and functional in its ancestors are called vestigial organs. For example the nictitating membrane in humans is a vestigial organ. It is a small, pinkish, reduced and...

Analogous Organs

Analogous organs are the organs of different animals which have different basic structure but perform same function. For example, the wing of a bird and the wing of a butterfly have different structures but they perform similar function so they are analogous organs....

Homologous Organs

 Homologous organs may be defined as the organs of different animals which have similar basic structure but different functions. For example, the flippers of a whale, the forelimbs of a frog and man have the same basic structures but they perform different functions,...

Organic Evolution

 The word organic evolution is made up of two words ‘organic’ which means ‘living organisms’ and ‘evolution’ which means ‘unfold’. So, organic evolution is the unfolding of the process of formation of different types of organisms. As we see that there are millions of...