Lecture 2 - A. 1.5 BYA B. Evolves multiple times C. Allows...

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Lecture 2 – The origins of life II I. The Oxygen Revolution A. Stromatolites create an oxygen rich atmosphere Stromatolites changed the world, at the time world still had a reducing atmosphere 1. Oxygen toxic to most existing prokaryotes At the time there was a lot of Iron in the Ocean and oxygen in the atmosphere, the Iron Oxidixed because of the oxygen and once there was no more Iron. O 2 seeped into the ocean II. From Prokaryote to Eukaryote -Created a new ecological niche, the consumer (heterotrophs) cells w/o organelles and cells w/ organelles, organelles adjust well to what they eat thus creating a mitochondria etc. -Anarobic metabolism produces 2 ATP -Aerobiotic metabolism produces 38 ATP A. The Endosymbiotic model (Lynn Margulis) Fig. 25.9 a. Evidence for the endosymbiotic model Organelle biochemistry homologous to living prokaryotes Organelle replicates by binary fission as do prokaryotes Organelles have their own DNA III. The domains of life established IV. From single cell to multicellular Eukaryote
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Unformatted text preview: A. 1.5 BYA B. Evolves multiple times C. Allows for the evolution of cellular specialization (i.e. tissues) V. The Cambrian Explosion A. 550 MYA the number of biological orders increases exponentially B. Burgess Shale fossils VI. Geologic Time A. Eons > Eras > Periods > Epochs B. Cambrian explosion occurs at beginning of the Paleozoic Era C. Paleozoic era packed with biological novelty (e.g. formation of bony fish, insect/ plant invasion onto land, etc) D. Mesozoic age of reptiles E. Cenozoic age of mammals VII. Plate tectonics dynamic earth Lecture 2 The origins of life II A. Pangea (Paleozoic) a. Gondwana (Mesozoic) b. Laurasia (Mesozoic) B. Plates associated with geological activity VIII. Mass extinctions A. Three major mass extinctions at beginning of Paleozoic, Mesozoic and Cenozoic eras (other minor mass extinctions occurred) B. Probable cause of Cenozoic extinction meteorite impacting Yucatan Peninsula...
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Lecture 2 - A. 1.5 BYA B. Evolves multiple times C. Allows...

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