PNB 2250 Lecture Notes - Lecture 1: Cambrian Explosion, Ocean Acidification, Hyperoxia
8 Sep 2016
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Or does live convert a basic ball of rock in a complex planet: ecosystem engineers. Ocean acidification (oceans used to be filled with iron before oxygen was in atmosphere) Global distribution of new materials (life changes geochemistry of planet: oxygenation. Used to be about 67% methane in air. Atmosphere used to be toxic to humans. 2 billion years ago prokaryotes became photosynthetic creating oxygen as a waste gas. Complex animals started to exist: key events. Oxidized methane created co2 needed for photosynthesis. Without oxygen animals would not exist: neoproterzic era. Before cambrian explosion- occurred over 50-60 million years. Lots of different animals species: cambrian explosion. Cant find soft-tissues in fossil records: ozone formation. Essential component to life- inside planet is molten core of iron that creates magnetic shield around planet and keeps solar radiation of sterilizing planet. May not have an accurate record of animals that existed before cambrian explosion: evolution. Can happen at a very fast time scale.
