(i) Formation of new species due to chanes in specific characters of several generatioons of living organisms as a response to natural selection is called as evolution.
(ii) At present, crores of species of plants, range from Chlorella to Banyan tree and animals ranging Amoeba to giant whale are existing on earth.
(iii) First primitive cell may have been formed from the mixture of different types of organic and inorganic compounds.
(iv) There may have been some differences among these cells and according to the principle of natural selection, some may have shown good growth and some may have perished which could not adjust with surrounding.
(v) Sustaining and selected organisms can perform reproduction and thereby, give rise to the new species with their own specific characters.
