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Evidence for Evolution by Natural Selection

Evidence for Evolution by Natural Selection. Science happens within a culture. What was the doctrine of the time?. TINTORETTO The Creation of the Animals 1550. Then along comes Darwin…. 1831-1836 22 years old ! . Then along comes Darwin…. & those dang finches !.

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Evidence for Evolution by Natural Selection

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  1. Evidence forEvolutionby Natural Selection

  2. Science happens within a culture What wasthe doctrineof the time? TINTORETTO The Creation of the Animals 1550

  3. Then along comes Darwin… 1831-1836 22 years old!

  4. Then along comes Darwin… & those dang finches! Descendantspecies Warbler finch Cactus finch Ancestralspecies Woodpecker finch Sharp-beaked finch Small insectivorous tree finch Small ground finch Warbler finch Large insectivorous tree finch Cactus eater Mediumground finch Tree finches Ground finches Insect eaters Seed eaters Vegetarian tree finch Large ground finch Bud eater

  5. Correlation of species to food source Seedeaters Flowereaters Insecteaters Rapid speciation:new species filling niches,because they inheritedsuccessful adaptations. Adaptive radiation

  6. Beak variation in Galapagos finches (c) Seed eater. The large groundfinch (Geospiza magnirostris)has a large beak adapted forcracking seeds that fall fromplants to the ground. (a) Cactus eater. The long,sharp beak of the cactusground finch (Geospizascandens) helps it tearand eat cactus flowersand pulp. (b) Insect eater. The green warbler finch (Certhidea olivacea) uses itsnarrow, pointed beak to grasp insects.

  7. Sloth fossils Glyptodont fossils Modern sloth Modern armadillos Why should extinct species & living speciesbe found on thesame continent?

  8. cells Big Idea 1 • The process of evolution drives the diversity and unity of life DNA

  9. What are the 4 lines of evidence that support Darwin’s ideas?… Dog Human Macaque Bird Frog Lamprey 8 32 45 125 67 0 10 20 30 40 50 60 70 80 90 100 110 120

  10. 1. What are the lines of evidence that support Darwin’s ideas? Fossil record 550 500 450 Equus 400 350 Body size (kg) 300 250 Merychippus 200 Mesohippus 150 Hyracotherium 100 50 Nannippus 60 55 50 45 40 35 30 25 20 15 10 5 0 Millions of years ago

  11. Evolution of birds • Archaeopteryx • lived about 150 mya • links reptiles & birds Smithsonian Museum, Washington, DC

  12. Evolution of land animals • 2006 Fossil Discovery of Early Tetrapod • “Tiktaalik” • “missing link” from sea to land animals • from swimming (0 legs) to walking (4 legs)

  13. ? ? ? ? Evolution of marine mammals Land Mammal Where are thetransitional fossils? But then,they actuallyfound my fossil! At first,I was justa joke! Aquatic Mammal

  14. 2. What are the lines of evidence that support Darwin’s ideas? Terminal bud Cabbage Brussels sprouts Artificial selection Lateral buds Leaves Flower cluster Kale Cauliflower Stem Flower and stems Kohlrabi Wild mustard Broccoli

  15. Selective breeding the raw genetic material (variation) is hidden there

  16. Natural selection in action MRSA

  17. 3. What are the lines of evidence that support Darwin’s ideas? Anatomical evidence

  18. Homologous structures spines leaves succulent leaves Don’t forgetour plant friends! tendrils needles colored leaves

  19. Analogous structures Don’t be fooledby their looks! Convergent evolution Those fins & tails & sleek bodies areanalogous structures! Does this mean they have a recent common ancestor? Solving a similar problem with a similar solution

  20. Convergent evolution What is thisevidence of? These animals look very similar but doesthat mean they have arecent common ancestor? marsupial mammals placental mammals

  21. Niche Placental Mammals Australian Marsupials Burrower Marsupial mole Mole Anteater Numbat Anteater Nocturnal insectivore Marsupial mouse Mouse Climber Spotted cuscus Lemur Sugar glider Glider Flying squirrel Stalking predator Tasmanian cat Ocelot Chasing predator Wolf Tasmanian “wolf” Parallel/convergent evolution Convergent evolutionof analogous burrowing characteristics

  22. Vestigial organs Why would whaleshave pelvis & leg bonesif they were alwayssea creatures? • These areremnants ofstructures that werefunctional inancestral species

  23. Dog Human Macaque Bird Frog Lamprey 8 32 45 125 67 0 10 20 30 40 50 60 70 80 90 100 110 120 4. What are the lines of evidence that support Darwin’s ideas? The sequence in DNA & proteinsis a molecularrecord of evolutionaryrelationships. Why compare DNA & proteins across species? Comparative hemoglobin structure Why comparethese genes? • compare common genes • cytochrome C (respiration) • hemoglobin (gas exchange) Number of amino acid differences between hemoglobin (146 aa) of vertebrate species and that of humans

  24. Building “family” trees

  25. "Nothing in biology makes sense except in the light of evolution." -- Theodosius DobzhanskyMarch 1973 Geneticist, Columbia University (1900-1975)

  26. Evolution is "so overwhelmingly established that it has become irrational to call it a theory." -- Ernst Mayr What Evolution Is2001 Professor Emeritus, Evolutionary Biology Harvard University (1904-2005)

  27. Don’t be a Dodo… Ask Questions!!

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