It is a small effort from me to make everybody to knw about the world of SCIENCE, about the real world os BIOLOGY, i have tried my level best to represent my knowledge in my own style so that it may give you a better understanding regarding whatever topic i write.
When we look into the bach history of our lovely planet earth we came accross the truth that it is 4500 millions years old when this solar system was formed and the molten earth at that time started to cool.
The basic timeline is a 4.5 billion year old Earth, with (very approximate) dates:
- 3.8 billion years of simple cells (prokaryotes),
- 3 billion years of photosynthesis,
- 2 billion years of complex cells (eukaryotes),
- 1 billion years of multicellular life,
- 600 million years of simple animals,
- 570 million years of arthropods (ancestors of insects, arachnids and crustaceans),
- 550 million years of complex animals,
- 500 million years of fish and proto-amphibians,
- 475 million years of land plants,
- 400 million years of insects and seeds,
- 360 million years of amphibians,
- 300 million years of reptiles,
- 200 million years of mammals,
- 150 million years of birds,
- 130 million years of flowers,
- 65 million years since the non-avian dinosaurs died out,
- 2.5 million years since the appearance of the genus Homo,
- 200,000 years since humans started looking like they do today,
- 25,000 years since Neanderthals died out.
