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Good Afternoon 9/28/15 Do Now – analysis of phylogeetic tree Write down HW Who shaped Darwin’s thinking (ppt take out notebook) Reading: A Sample Study HW Lesson 10.1 Vocabulary WS Grade sheets will be given out at end of period See me with questions. I can not answer questions now until I have given out all sheets.
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Ideas that shaped Darwin’s Thinking James Hutton: 1795 Theory of Geological change Forces change earth’s surface shape Changes are slow Earth much older than thousands of years
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Ideas that Shaped Darwin’s Thinking Charles Lyell Book: Principles of Geography Geographical features can be built up or torn down Darwin thought if earth changed over time, what about life?
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Lamarck’s Theory of Evolution Change through Use and Disuse- when environments changed so did organisms. If an organism began to use an organ more than they had in the past……it would increase in it’s lifetime If an organism did not use it would shrink and disappear.
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example: If a giraffe stretched its neck for leaves, for example, a "nervous fluid" would flow into its neck and make it longer. Its offspring would inherit the longer neck, and continued stretching would make it longer still over several generations. Acquired characteristics would be passed on to offspring.
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Lamarck also proposed that organisms were driven from simple life forms to more complex forms Why are bacteria still alive today? Lamarckian inheritance is used today as a historical contrast for our understanding of inheritance only
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Comparing Lamarck and Darwin
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Population Growth Thomas Malthus- 19th century English economist If population grew (more Babies born than die) Insufficient living space Food runs out Darwin applied this theory to animals
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Summary of Darwin’s Theory Individuals in nature differ from one another Organisms in nature produce more offspring than can survive, and many of those who do not survive do not reproduce. Because more organisms are produce than can survive, each species must struggle for resources Each organism is unique, each has advantages and disadvantages in the struggle for existence
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Summary (cont.) Individuals best suited for the environment survive and reproduce most successful Species change over time Species alive today descended with modification from species that lived in the past All organisms on earth are united into a single family tree of life by common descent
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Adaptation/Mutation/Natural Selection/ Selective Breeding Examples Primate A Primate B Mutation Adaptation Natural Selection
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Adaptation/Mutation/Natural Selection/ Selective Breeding Examples Primate A Primate B MutationDevelops opposable thumb Adaptation Natural Selection
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Adaptation/Mutation/Natural Selection/ Selective Breeding Examples Primate A Primate B MutationDevelops opposable thumbDoes NOT develop opposable thumb Adaptation Natural Selection
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Adaptation/Mutation/Natural Selection/ Selective Breeding Examples Primate A Primate B MutationDevelops opposable thumbDoes NOT develop opposable thumb AdaptationBecause of his thumbs, primate A can now handle tools and has a better chance of survival Natural Selection
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Adaptation/Mutation/Natural Selection/ Selective Breeding Examples Primate A Primate B MutationDevelops opposable thumbDoes NOT develop opposable thumb AdaptationBecause of his thumbs, primate A can now handle tools and has a better chance of survival Primate B is less adapted to his environment so it is more difficult for him to survive Natural Selection
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Adaptation/Mutation/Natural Selection/ Selective Breeding Examples Primate A Primate B MutationDevelops opposable thumbDoes NOT develop opposable thumb AdaptationBecause of his thumbs, primate A can now handle tools and has a better chance of survival Primate B is less adapted to his environment so it is more difficult for him to survive Primate A passes mutation on to his children Natural Selection
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Adaptation/Mutation/Natural Selection/ Selective Breeding Examples Primate A Primate B MutationDevelops opposable thumbDoes NOT develop opposable thumb AdaptationBecause of his thumbs, primate A can now handle tools and has a better chance of survival Primate B is less adapted to his environment so it is more difficult for him to survive Primate A passes mutation on to his children Primate B produces more children without the opposable thumb Natural Selection
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Adaptation/Mutation/Natural Selection/ Selective Breeding Examples Primate A Primate B MutationDevelops opposable thumbDoes NOT develop opposable thumb AdaptationBecause of his thumbs, primate A can now handle tools and has a better chance of survival Primate B is less adapted to his environment so it is more difficult for him to survive Primate A passes mutation on to his children Primate B produces more children without the opposable thumb Natural Selection Many Generations later those Out number those without because environment. Today all primates primates with opposable they are better suited for their have opposable thumbs
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Natural Selection & Artificial Selection Natural variation--differences among individuals of a species Natural Selection - Artificial selection- nature provides the variation among different organisms, and humans select those variations they find useful. Natural selection is the driving force of evolution. The environment selects the winners and losers. In artificial selection we are the shapers of other living things. the process in nature by which only the organisms that are best adapted to their environment tend to survive and reproduce, transmitting their genetic characteristics to the next generation
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