Evidence for Evoluti14

Evidence for Evoluti14 - Evidence for Evolution DNA...

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Evidence for Evolution DNA sequenced from old magnolia In the paper I explain here, the authors (Golenberg et. al., 1990) sequenced an 820 bp region (the rbcL gene) from the chloroplast DNA of a compression fossil of a magnolia. [A brief explanation of chloroplasts (and their DNA): Chloroplasts are organelles found in the cells of plants. They are the site of photosynthesis. These organelles are autonomously replicating (i.e. there replication is not tied to the cell cycle.) They contain their own genome, a single, circular "chromosome". DNA sequences of their "genomes" and their autonomous nature led Lynn Margulis to speculate that chloroplasts were once free living organisms that later became endosymbionts in other cells. She also thinks this explains the presence of mitochondrian in cells (as well as basal bodies). This is now generally accepted. But, that's another story] The fossil leaf they extracted the DNA was from a compression fossil formed when the leaf sank to the bottom of a lake. The conditions were very anoxic (lacking in oxygen) and as a result the
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Evidence for Evoluti14 - Evidence for Evolution DNA...

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