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Evolution Evolution- changes that have transformed life over time.

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Presentation on theme: "Evolution Evolution- changes that have transformed life over time."— Presentation transcript:

1 Evolution Evolution- changes that have transformed life over time

2 Biological Diversity= variety of living things How did different organisms arise? How are they related?

3 Charles Darwin- (1831) – naturalist – HMS Beagle – Galapagos islands- studied finches – Book: (1858) The Origin of Species

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5 Patterns of Diversity Organisms well suited to environment Why were dif animals in similar environments at dif parts of the world?

6 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?

7 Galapagos Islands Dif Climates Tortoise’s differed on each island in predictable ways Birds differed on islands

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11 Were animals on dif islands once from the same species?

12 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

13 Hutton/Lyell(1830)- geological change Earth changed over time – erosion – shift in plate

14 Malthus-(1798) Principle of Populations – More offspring are produced than can survive Wallace- (1858) mechanism of evolutionary change

15 On the Origin of Species 1. Variation among species – Artificial selection- nature provided variation and humans selected those variations to be more useful.

16 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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18 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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20 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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22 5. Descent with Modification- each living species has descended with changes from other species over time Change- change in environment

23 – Changes in different environments – Ex: Rabbits

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25 Evolution Evidence 1. Fossil Record- document intermediate stages of life

26 2. Geographic Distribution of Living Species- Many environments similar= same pressures of natural selection= different animals evolved common features

27 3. Homologous Body Structure- structures that evolved from a single structure in a common ancestor. Vestigial organs-Organs reduced in size only traces left

28 4. Similarities in embryology- embryos similar at various stages of development

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30 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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