About 2000 million years ado, small bacteria developed in the seas which were the first forms on the earth. These were followed by creatures like worms and jelly fish water and on plants and algae on land.

About 450 million year ago, the first shelled animals which lived under water, the trilobites were born. For another million years, life developed in the water and plants thrived on land. The first formed during this time were Jamoytius, Pteraspis and Hemicyclaspis and the first teal plant to appear on land was the cooksonia plant.

With the growth of plants on land the first insects like the millipedes and dragon-fly were born. Since inhabitable conditions were also available, some fish had evolved into animals and were capable to live both on land and in water. Thus, came into being the first amphibians. These amphibians continued to lay their eggs in water but crawled on the shore which helped them t develop thicker skin and stronger limbs. Some later amphibians succeeded in playing their eggs out of water, and so become the first reptiles. The first reptile was the Hylonomus.

Dinosaurs

Life continued to thrive and about 150 million years ago, came the age of the Dinosaurs. These creatures included various types of reptiles and terosaurs which were capable of flying or gliding. Most dinosaurs had huge bodies with thin snake- like necks and small heads.

Compsognathus- whales and dolphins

When the dinosaurs became extinct, an enormous variety of mammals and birds evolved. The first bird was the Archaeopteryx which appeared in the Jurassic period. Some pre-historic mammals looked very different to modern kinds. Mammals also evolved in the ocean while others learnt to fly.

Africa elephant

About 2 million years ago, man first evolved in the continent of Africa and migrated to various parts of the world. The first human being was called Home Sapiens. It was during this period, that the first of many ice ages gripped the earth but life continued with its cycle of evolution.