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Biological evoluti - Biological evolution What is evolution Why study evolution Evolutionary changes are taking place all around us Evolution helps

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1 Biological evolution • What is evolution? • Why study evolution? – Evolutionary changes are taking place all around us – Evolution helps us understand the history and diversity of life What is the ORIGIN OF SPECIES ? How are all these species similar and different from each other? Species are permanent; life is unchanging Maybe species aren’t permanent - maybe they change -- Similarities between fossils and living organisms -- Fossils = ancient versions of living species? FAST: (Cuvier, 1769-1832) Canyonlands National Park, Utah Geological change – how does it occur? SLOWER: (Hutton, 1726-1797; Lyel , 1797-1875) Major disturbances Æ change ht p:/ msnbcmedia2.msn.com/j/msnbc/Components/Photos/051 03/051 03_marshlands_vlrg.widec.jpg Gradual change over time due to natural processes ht p:/ www.sc.edu/library/spcol /nathist/darwin/principles.jpg
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2 What causes species to change over time? Jean-Baptiste de Lamarck (1744-1829) – Best explanation for relationship to fossils is that LIFE EVOLVES , changes over time Charles Darwin (1809-1882) Beagle A sea voyage helped Darwin frame his theory of evolution What causes species to change over time? Some of Darwin’s observations: New and very different species and related fossils Gradients of changes in species within & among continents, islands l Alfred Russell Wallace (1823-1913) Species present today descended from ancestral species - _______________________ The mechanism responsible for change in a species over time – _______________________
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3 Organisms have great capacity for reproduction Æ More individuals are produced than can survive and reproduce Thomas Malthus, 1797, Essay on the Principle of Population But…. Population sizes remain relatively stable Natural Selection No two individuals are the same Æ Survival can be influenced by differences in heritable traits Much of this variation is ____________ Æ Individuals with traits that enhance survival & reproduction pass these traits on to their offspring.
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This note was uploaded on 05/07/2008 for the course ZOO 101 taught by Professor Sharon during the Spring '08 term at Wisconsin.

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Biological evoluti - Biological evolution What is evolution Why study evolution Evolutionary changes are taking place all around us Evolution helps

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