BIOL 2200 Chapter Notes - Chapter 519-531: Ediacaran Biota, Cellular Respiration, Cambrian Explosion
4 Feb 2017
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Document Summary
Macroevolution = the broad pattern of evolution above the species level. Chemical and physical processes could have produced simple cells through four steps: Protocell = droplet with membrane that maintained an internal chemistry different than its surroundings. The earth started as a large cloud of dust and rock. Life could not form on earth until collisions into earth stopped. All available water was in a vaporized form. The first atmosphere had little oxygen and mostly contained water vapor and various compounds. Eventually water vapor cooled and hydrogen went into the atmosphere. Hypotheses that earth was reducing environment and that early oceans were a mixture of organic compounds. Some evidence to suggest that the earth was mostly made up of nitrogen and carbon, and was neither oxidizing nor reducing. Modern equipment shows that numerous amino acids formed in conditions that simulated a volcanic eruption. Hydrothermal vents = areas on the seafloor where heated water and minerals gush from.
