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Published byGeorge Harmon Modified over 8 years ago
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Evolution Evolution- changes that have transformed life over time
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Biological Diversity= variety of living things How did different organisms arise? How are they related?
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Charles Darwin- (1831) – naturalist – HMS Beagle – Galapagos islands- studied finches – Book: (1858) The Origin of Species
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Patterns of Diversity Organisms well suited to environment Why were dif animals in similar environments at dif parts of the world?
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Living Organisms and Fossils Fossils-preserved remains of ancient animals Some fossils had similarities of living org. How were these fossil species related to living organisms?
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Galapagos Islands Dif Climates Tortoise’s differed on each island in predictable ways Birds differed on islands
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Were animals on dif islands once from the same species?
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Scientists Buffon- (1700) earth older than 1,000 years – Fossils and living organisms similar but not exactly the same Lamarck- (1800)proposed life evolves or changes – Evolution was a process of adaptation – by use or disuse organisms lost /acquired traits – Traits were passed on
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Hutton/Lyell(1830)- geological change Earth changed over time – erosion – shift in plate
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Malthus-(1798) Principle of Populations – More offspring are produced than can survive Wallace- (1858) mechanism of evolutionary change
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On the Origin of Species 1. Variation among species – Artificial selection- nature provided variation and humans selected those variations to be more useful.
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2. Struggle for existence- more offspring produced than can survive Those more suited for the env. Survived and passed on traits
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3. Survival of the Fittest- Natural Selection Fitness- ability of an organism to survive and reproduce Adaptation- inherited characteristic that increases an organisms chance of survival/reproduce
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4. Natural Selection- mechanism of evolution – Traits are selected by nature – Traits passed on to offspring, trait increases over time – Over time population changes Over time natural selection results in changes in inherited characteristics of a population
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5. Descent with Modification- each living species has descended with changes from other species over time Change- change in environment
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– Changes in different environments – Ex: Rabbits
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Evolution Evidence 1. Fossil Record- document intermediate stages of life
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2. Geographic Distribution of Living Species- Many environments similar= same pressures of natural selection= different animals evolved common features
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3. Homologous Body Structure- structures that evolved from a single structure in a common ancestor. Vestigial organs-Organs reduced in size only traces left
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4. Similarities in embryology- embryos similar at various stages of development
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Natural Selection Trait must be inherited Variation- difference among members of the same species More offspring produced than can survive Evolution occurs over time, populations evolve not individuals
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