Sydney Ruben & Minahil Khan
BIg Bang Theory -
The Big Bang Theory refers to the expansion of the Universe, and it occured 13 billion years ago, but it was proposed on 1927 by Georges Letmai.
Formation of Hydrogen Atoms and Cells-
The formation of hydrogen atoms started 13,810,000,000 years ago. The formation of our sun was 13, 410,000,000 years ago. The first cell on Earth was prokaryotic.
There were five mass extinctions in Earths history. The first extinction was "Ordovician - Silurian, and was the third largest extinction in Earths history. Many sea creatures were reduced in numbers. The next extinction was "Late Devonian" where three-quarters of all species on Earth died. The thrid extinction, "Permian", was when 96% of all species died, and only 4% remained on Earth. The "Triassic- Jurassic" extinction resulted in climate change, and an asteroid being blamed for the loss of life. "Cretaceous- Tertiary", killed all dinosaurs on Earth
Homo sapiens first evolved 200,000 years ago in Africa. Other early humans that were living at this time gathered and hunted food.