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Unformatted text preview: Chapter 1: Adaptation by Natural Selection Explaining Adaptation before Darwin- The human eye is a complex structure that is specifically adapted to our environment- Any substantial changes in the structure of the eye would keep the eye from functioning- During Darwin’s time, many people believed that the eye had come about by divine creation o William Paley, Natural Theology , 1802 o The structure was too complex to randomly come about through natural processes so Paley though that an intelligent creator, God, had designed the eye. Darwin’s theory of Adaptation- Darwin’s postulates: o Although adaptations are constantly expanding, there comes a point where the environment can support no more. “struggle for existence” o Organisms within populations vary, and this variation can affect the ability of the organism to survive and reproduce o This variation is passed down through generations- This process is known as natural selection or evolution by variation and selective retention- Peter and Rosemary Grant studied one species of Darwin’s finches noting their size, weight, etc. o A few years into their study, there was a drought that led to a shortage of small seeds The population decreased from 1200 to 800 • The environment could not support the population The beak size increased • Birds with bigger beaks could crack open the larger seeds that were left behind...
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This note was uploaded on 04/21/2009 for the course ANTH 200Lg taught by Professor Yamashita during the Fall '07 term at USC.
- Fall '07