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Unformatted text preview: Lecture 5 - Evolution 2/25/2011 Nicola Davies 2011 Evolution Lecture 5 February 25, 2011 2 Evolution Biologys unifying concept Underlies all biological facts and phenomena Understanding evolution will make understanding biology easier Misunderstanding evolution ranges in effect from mild confusion to a complete inability to understand biology Occurs when selection acts on a preexisting characteristic The selective force does not cause change in an organism Evolution does not have a plan! 3 Evolution: History Proposed by Darwin 150 years ago Published On the Origin of Species by Means of Natural Selection Based on his observations as a naturalist Laid out clear, testable hypotheses for how species arose Also made predictions of future scientific discoveries Fossils are datable by the layer of rock they are within and by radioisotope decay Provided evidence for Darwins theories Allowed evolutionary history of many plants and animals to be determined 4 The Microbial Fossil Record Before 500 m.y.a. few fossils exist First 3.5 b.y. of life only microbes on earth Left little fossilized evidence...
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This note was uploaded on 11/17/2011 for the course BIO 456 taught by Professor Smith during the Spring '11 term at Aberystwyth University.
- Spring '11