Organic Evolution

More and more creation of organism by gradual changes from low categories animal to higher animal is called organic evolution. There are several evidence regarding organic evolution.

Homologous organ : Organ which are seen different due to use in various function but its structure and embryonic embryonic development are similar.
Example - Flipper of Whale, featurer of bat, forlimb of horse, Paw of cat and hands of human.

Analogous organ : Organ which looks similar due to be used in similar function but their internal structure and embryonic development are different.
Example - feature of butterfly, bats and birds all looks similar but their internal structure and origin are different.

Vestigial organ : These are organs which appear functinless in an organism but functional in their ancestor.
Example - vermiform appendix of large intestine and nictitating membrane of human. Vermiform appendix is functional in herbivorous mammal even now.

Fossils : Fossils are the remains of ancient plant or animal which provide evidence for evaluation. Example - Archaeoptery.

Archaeopteryx : It is a fossils look like bird but near a number of features found in reptiles. So, it is a connecting link between aves and reptile.

Organic Evolution