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History of Earth (Palaeocene Era (Mesozoic Era (First life on Earth…

- - - - Archean Era
        
        Earth's Formation and Birth
        
        Universe Formation: Approximately 13.8 billion years old
        
        The Earth is approximately 4.5 billions years ago. Its oldest materials being 4.3 billions years old zircon crystals.
        
        Archean Eon, also spelled Archaean Eon, the earlier of the two formal divisions of Precambrian time (4.6 billion to 541 million years ago) and the period when life first formed on Earth.... Records of Earth's primitive atmosphere and oceans emerge in the earliest Archean Era.
      - The history of life on Earth began about 3.8 billion years ago, initially with single-celled prokaryotic cells, such as bacteria. The first life may have developed in undersea alkaline vents, and was probably based on RNA rather than DNA.
- - - - Holocene Era
        
        Present Day: August 24, 2018.
        
        From 11.7 thousand years to present day, the Holocene (or Recent) is the current geological era which started some 11,500 years ago when the glaciers began to retreat. This retreat marked the end of the glacial phase of the most recent ice age. Its character was set by the spread of forests as the ice retreated and then by their shrinkage as mankind's demand for timber and agricultural and grew. Although we think of the Holocene as a warm time for the planet, we are still in an ice age. This is indicated by the presence of ice caps at the poles - the planet as a whole is just in an interglacial phase.
      - Began 2.6 million and end at 11.7 thousand years ago. During the Pleistocene, glaciers came and went, resulting in a series of ice ages punctuated by warmer periods. There were at least 20 cycles of this advance and retreat. During the ice ages, global temperatures were 5 degrees centigrade cooler than today and it was much drier, since much of the world's water was locked up in massive ice sheets. The expansion of the deserts and the action of glaciers grinding up rocks meant that dust storms would have been a lot more common in the Pleistocene than they are now. Our species evolved during the era.