Evidence For Evolution 1)Fossil Record 2)Biogeography 3)Homologous Structures 4)Vestigial Structures 5)Comparative Embryology 6)Molecular Evidence 7)Imperfections.

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<p>Evidence For Evolution</p> <p>Evidence For EvolutionFossil RecordBiogeographyHomologous StructuresVestigial Structures Comparative Embryology Molecular Evidence Imperfections of Adaptations </p> <p>Rocks formed by layers (sediments) settling on top are called sedimentary.Oldest Layers deposited first, oldest fossilsNewest LayersDeposited last, newest fossilsGeologists can determine just how old each layer is</p> <p>Fossils are within that time period</p> <p>Most of these layers are sedimentary rock.</p> <p>The Fossil Record of Horses</p> <p>Record shows size and shape progressionUsed to be as small as dogs!</p> <p>Some fossils are simply older versions of insects much like those found on Earth todayThe Fossil RecordA story we piece together as we find new fossilsClearly, the fossil record tells us of times when life on Earth was very different than it is todayThe story tells us life has gradually become more complex. </p> <p>a very scary salamander</p> <p>Fossil of cells that resemble modern cyanobacteria (3.5 billion years old)</p> <p>BiogeographyThe distribution of different organisms around the planetBiogeography Video (7:03)</p> <p> jack rabbit (a lagamorph) kangaroo (a marsupial) patagonian hare (a rodent) These 3 organisms live in similar environments around the world (the US, Australia, and Argentina)What is similar between these different animals?Homologous StructuresStructures used for different purposes that indicate a common ancestryWhy would appendages used for different purposes have the same underlying bone structure?</p> <p>Vestigial Structures</p> <p>Structures that have no function in the organism </p> <p>The only explanation is that they are remnants of evolutionHuman AppendixWhale HipsSnake SpursHuman Tail BoneComparative Embryology</p> <p>Can you tell which is which? mouse, turtle, chick, pig, and human Turtle Mouse Human ChickPigWhy would all these very different organisms need to develop the same way?Molecular EvidenceCompare DNA sequences of different organisms to see how similar they are!</p> <p>% Similarity Between SpeciesHuman DNA?96% similar to chimpanzee 85% mouse 50% fruit flies </p> <p>Just as DNA shows you descended from your parents it also shows you descended from the grandparent of them all ~3.8 billion yrs ago </p> <p>Imperfections of AdaptationsThe Pandas ThumbEats bamboo, not meatDeveloped thumb grasp bambooNot a perfect solution, but it works!</p> <p>Important Points To Remember About The Process of Evolution</p> <p>Evolution acts on populations not individuals</p> <p>Individual organisms do not improve themselvesNature selects the best of the members of a population to survive and produce the next generation</p> <p>Evolution does not produce new adaptations!</p> <p>It amplifies (increases) or diminishes (decreases) variations that are already present</p> <p>Mutations may produce such unique features but selection enhances them</p>

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