BCOR 12 1st Edition Lecture 9 Outline of Last Lecture I Microevolution and macroevolution connection II Major Characters used for Phylogenetic trees cont III Homology vs Analogy IV Brief Lecture Review of Past Lectures V Introduction to Chapter 25 Cell Theory Outline of Current Lecture I Protocells and Life Form Abilities II Geological Record of Earth s History III Some Key Event s in Life s History IV Photosynthesis the Oxygen Revolution V Endosymbiont Theory Current Lecture Protocells Success Most successful Protocells Exploited their resources most efficiently Passed on their abilities to future generations o NATURAL SELECTION Protocell abiotic lead to the true cell biotic There is limited data on how the protocell became a true cell but experiments are being done in the laboratory to determine how this occurred There are three main differences between non life and life forms and they are that ONLY life forms can I II III Reproduce Accurately replicate themselves Metabolize Geological Record of Earth s History The Earth s history is separated into 3 eons These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute I II III Archaean 4 6 BYA 2 5 BYA Proterozoic 2 5 BYA 542 MYA Phanerozoic 542 MYA Present The Phanerozoic the current eon is split into three different eras I II III Paleozoic Era 542 MYA 251 MYA Mesozoic Era 251 MYA 65 5 MYA Cenozoic Era 65 5 MYA Present Boundaries between the eras correspond with major extinction rates Key Event s In Life s History I The origin of the single cell organisms II The origin of multicellular organisms shows life is becoming more complex III Colonization of land by plants and other organisms lead to a huge diversification Stromatolites layered rock that results from the activities of prokaryotes that bind thin film of sediment together o Some Stromatolites are 3 5 billion years old but are so complex it suggests that prokaryotes are much older than that Prokaryotes were the sole inhabitants of Earth from 3 5 2 1 BYA Photosynthesis and the Oxygen Revolution Cyanobacteria photosynthetic prokaryotes are the ancestors of chloroplasts and caused the increase of Oxygen in the atmosphere The Oxygen Revolution occurred about 2 BYA and caused the extinction of many prokaryotes for they couldn t survive in a world with so much oxygen Some groups that survived adapted and started used cellular respiration to harvest energy Cellular respiration using oxygen to produce energy ATP synthase involved in photosynthesis and cellular respiration with the formation of energy molecules Evidence strongly suggests that mitochondria and chloroplasts have prokaryotic ancestors due to their possession of their own genetic material RNA the ATP synthase gene membrane and ribosomes This is also known as the Endosymbiont Theory