Timeline of Evolution of Earth
Time Period | Event |
---|---|
4.6 billion years ago | Formation of the Earth from the solar nebula. |
4.5 billion years ago | Differentiation of the Earth into core, mantle, and crust layers. |
4.1 – 3.8 billion years ago | Late Heavy Bombardment period, with intense meteor impacts. |
4 billion years ago | Formation of the earliest oceans and solidification of the Earth’s crust. |
3.8 billion years ago | Earliest evidence of life on Earth (fossil record of single-celled microorganisms). |
2.7 billion years ago | Emergence of oxygen-producing cyanobacteria, leading to the gradual oxygenation of the atmosphere. |
2.5 billion years ago | Formation of the first stable continents and the onset of plate tectonics. |
1.8 billion years ago | Appearance of eukaryotic cells (cells with a nucleus). |
1 billion years ago | Development of multicellular organisms. |
541 million years ago | Start of the Phanerozoic Eon, characterized by the appearance of complex life forms with hard shells and skeletons (the “Cambrian Explosion”). |
470 million years ago | First plants and fungi colonize the land. |
360 million years ago | Emergence of the first amphibians. |
290 million years ago | First reptiles appear. |
230 million years ago | First dinosaurs evolve. |
200 million years ago | First mammals appear. |
66 million years ago | Mass extinction event leads to the extinction of dinosaurs and the rise of mammals. |
2.6 million years ago | Emergence of the earliest humans (genus Homo). |
Evolution of Earth Class 11 Geography Notes
The Earth is a remarkable planet that has undergone a fascinating journey of formation and evolution over billions of years. From its humble beginnings as a hot, molten sphere to the diverse and life-sustaining world we know today, the Earth has witnessed countless transformations shaped by cosmic events and geological processes.
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