Ch 16 Darwin’s Theory of Evolution 16.1 Darwin’s voyage Evolution Darwin’s voyage Observations on Beagle 1 2 3 * * Species vary globally Species vary locally Mockingbirds Species vary over time Specimens Putting the pieces together 16.2 Ideas that shaped Darwin Hutton Uniformitarianism Lyell Hutton’s and Lyell’s conclusion Lamarck Previous evolution thoughts Helped Darwin Evaluating Lamarck Malthus and population growth Helped Darwin Artificial selection Helped Darwin 16.3 Darwin presents his case Draft Wallace The Origin of Species Natural selection occurs when 1 2 3 Struggle for existence Variation Adaptation Fitness Survival of the fittest Natural selection Natural selection steps 1 2 3 4 Grasshoppers 1 2 3 4 Natural selection and adaptation Environmental changes Common descent 16.4 Evidence of evolution Biogeography Distantly related but similar Age of the Earth Recent fossils finds of whales - - - - Homologous structures Analogous structures Vestigial structures Embryology Genetic code Homologous molecules Testing natural selection Testable assumptions 1 2 What they did What they found