How Did Life Begin HARD QUESTIONS 4 Billion Ma 1 What was Earth s environment like when life arose 2 How is life defined and how did it arise from non life 3 What were the characteristics of the very first cells What is Life Ability to store and transmit information having a genotype Ability to express that information having a phenotype Ability to evolve change over time 1 Ribozyme What came first Tetrahymena thermophila genotype phenotype Protein DNA RNA RNA evolution in a test tube Q RNA Virus Test tube evolution of Ribozyme Tetrahymena Tetrahymena ribozyme Monomers of CHON generation 1 generation 9 2 Panspermia Life elsewhere in the Universe Murchison Meteorite alanine glycine proline valine Fossil Bacteria proteins Oparin Haldane Model Stanley Miller s Apparatus 1953 Glycine Alanine Assemblage of biological polymers Oldest known sedimentary rocks Nucleotides Carbonaceous apatite crystal Akilia Island Greenland 3 8 billion years old 10 base nucleotides bind to clay montmorillonite 20 bp Banded iron formation Akilia Island Greenland 3 8 billion years old 11 bp Inclusion in crystal perhaps produced by living organism ratio 12C to 13 C Chain 10 bases long 3 Apex Chert Fossils of Western Australia History of Impacts Earth 3 5 billion yrs Cyanobacteria J W Schopf Cr adle of Life 1999 Living 950 Ma Living 850 Ma Living 1 5 billion Living 2 1 billion 4
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