Bio; Lecture 03; Life

Bio; Lecture 03; Life - Principles of Biology 2 BIO U102...

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Principles of Biology 2 BIO U102 1-11-07 Origins of Life Calendar analogy Clock analogy o The earth originated between 5-4.5 billion years ago; however meteorites bombarded the earth making it unlikely for life to survive o Life on Earth originated between 3.5 and 4 billion years ago The earliest prokaryote fossils were found 3.7 billion years ago For the first three quarters of evolutionary history, Earth’s only organism were microscopic and mostly unicellular Prokaryotes diverged into two main evolutionary branches: bacteria and archaea—which thrive today Archaea: Heat loving bacteria Isolated from other microorganisms because they liked the heat Some chose to live in environments that have high concentrations of saline (Halophiles) PCR polymerases extracted from archaea prokaryotes Some don’t like aerobic conditions, and choose to live in environments with low concentration of oxygen Favorable environments like early earth The oldest fossils that have been uncovered were embedded in rocks from Western Australia that are 3.5 billion years ago. No clear fossils have been found in the oldest surviving
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Bio; Lecture 03; Life - Principles of Biology 2 BIO U102...

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