ENV100Y5 Lecture Notes - Lecture 6: Panspermia, Chemotroph, Heterotroph
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ENV100Y5 Full Course Notes
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What we have right now is our secondary atmosphere earth has had 2 atmospheres: primitive + secondary. Atmosphere = collection of gases, makes up the air we breathe. Earth"s primitive atmosphere was ripped away due to radiation. Our atmosphere today is nitrogen + oxygen. Secondary atmosphere came from volcanic eruptions during early earth (this is called degassing the planet) These volcanoes erupt and gases come out for the first time. These gases are not n or o2. Early atmosphere was reducing oxidation is prevented by removal of o2 (no o2, lots of h ions). There were lots of greenhouse gases, it was hot and dense. Eventually surfaces cooled enough for liquid water oceans are about 4. 4 ga old. The water was still very hot it was constantly being evaporated and precipitated. Heterotrophic/primordial soup: the first living organism was a heterotroph life came from inorganic chemicals in the ocean. Amino acids/nucleotides accumulate in oceans creates primordial soup.
