BIOL 2400 Chapter Notes -Swine Influenza, Cosmic Microwave Background, 1918 Flu Pandemic
12 Feb 2013
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Age of universe (13. 7 0. 2 billion years) Origin of solar system and earth (4. 6 billion years) Radiometric dating of meteorites and moon rocks. Products: amino acids, adenine, guanine, cyanoacetylene, various sugars (ribose) An rna polymer can act as a template for replication. Self-replicating molecules can undergo the process of natural selection. Dna is structurally more stable and can form longer molecules compared to rna. Rna typically is a single stranded molecule. Evidence of cellular life ~3 3. 5 billion years ago. Stromatolite-like fossils: modern stromatolites are formed by cyanobacteria. Carbon-12 and carbon-13 ratios in preserved kerogen (organic compound) dating to 3. 85 billion years suggest the kerogen was part of a living organism. Carl linnaeus introduced the modern practice of taxonomy and nomenclature. Linnaeus felt that species and generae were fundamental units of classification, whereas higher taxa were somewhat arbitrary. No natural mechanism to explain hierarchical classification until darwin"s work.
