One of these was a very simple plant called alga.Mosses and liverworts came next,followed by ferns and other larger plants.
The first animals were probably a type of shellfish called brachiopods.The oldest fossils discovered were brachiopods and an insect like sea dwelling creature called trilobites.So fish appeared on earth before other anmals.
Relatives of the spider and scorpions were probably the first creature to leave the sea and live on land.Later,more complex forms of life called amphibians appeared which live both land and water.The first mammals appeared along with the dinosaurs,but in beginning, mammals were very tiny.
Humans as known today, are very late arrival in this world, but are known the most dominant begin.
