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More on microevolution

More on microevolution. Movie (Simpsons). Evolution Evidence. Fossil : Remnant or impression of organism that lived in the past Mostly in sedimentary rocks. Grand Canyon. Evolution Evidence. Fossil types: Organic : coal (reduced carbon: burns!). Evolution Evidence. Fossil types:

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More on microevolution

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  1. More on microevolution • Movie (Simpsons)

  2. Evolution Evidence • Fossil: Remnant or impression of organism that lived in the past • Mostly in sedimentary rocks Grand Canyon

  3. Evolution Evidence • Fossil types: • Organic: coal (reduced carbon: burns!).

  4. Evolution Evidence • Fossil types: • Source energy Coal seam

  5. Evolution Evidence • Fossil types: • Thank “Lumpy Coal”.

  6. Evolution Evidence • Fossil types: • Amber: fossil resin (conifer trees)

  7. Evolution Evidence • Fossil types: • Jurassic Park! Mosquitoes in amber to get dinosaur DNA

  8. Evolution Evidence • Fossil types: • Mineralize hard parts: “petrification” replaces organic molecules with rock

  9. Evolution Evidence • Ex, Petrified Forest National Park, Arizona.

  10. Evolution Evidence • Fossil types: • Cast: Original structure dissolves but sediments retain shape Casts of squid-like animal called an ammonite

  11. Evolution Evidence • Fossil types: • Casts: footprints!. Dinosaur footprints from Montana

  12. Evolution Evidence • Principle of superposition: Old rocks lower, young rocks higher.

  13. Evolution Evidence • Principle of superposition: Old rocks lower, young rocks higher. • “Relative dating”: age fossils relative to each other.

  14. Evolution Evidence • Fossils show how life evolved

  15. Cool fossils • Dinosaurs! • Reptiles dominated Mesozoic Era.

  16. Cool fossils • Dinosaurs! • Movie stars today!. T. rex skull

  17. Cool fossils • What killed them off? Asteroid impact.

  18. Cool fossils • Crater image (buried under ocean sediment) • (Earth owee!).

  19. Evolution Evidence • Radioactive dating: Decay radioactive isotopes determines time since formation

  20. Evolution Evidence • Radioactive dating: Decay radioactive isotopes determines time since formation Start 1 isotope, which gives off radioactivity and becomes another isotope (predictable rate)

  21. Evolution Evidence • Radioactive dating: Decay radioactive isotopes determines time since formation Rate measured by “half-life”: time for half original material to decay.

  22. Evolution Evidence • Radiocarbon dating: Radioactive Carbon-14 • Half-life (5370 years): good 4 fossils < 60,000 yr old Shroud of Turin (1988) 1260-1390?

  23. Evolution Evidence • Potassium-Argon dating: Radioactive Potassium forms Argon (volcanic rocks) • Half-life 1.3 billion years: good 4 fossils millions years old.

  24. Relative ages converted to absolute ages (years) • Humans only in last 2 million years.

  25. Evolution Evidence • “Vestigial structures”: Nonfunctional remnants of useful structures.

  26. Evolution Evidence pelvic girdle • Ex, some snakes: pelvis/leg bones • Human coccyx (“tailbone”). coccyx (bones where many other mammals have a tail) thighbone attached to pelvic girdle small bone attached to pelvic girdle

  27. Evolution Evidence • Blind cave organisms. Vestigial (nonfunctional) eyes. Blind crayfish

  28. Evolution Evidence • Blind cave organisms. Vestigial (nonfunctional) eyes. Blind cave salamander Blind cave fish

  29. Evolution Evidence • Comparative anatomy: Same structures, modified to current use • Ex, vertebrate forelimbs

  30. Evolution Evidence • Comparative embryology (embryology: study of early stages of development): Embryos related organisms go through similar stages

  31. Evolution Evidence • Comparative embryology (embryology: study of early stages of development): Embryos related organisms go through similar stages fish reptile bird (chicken) mammal (human)

  32. Evolution Evidence • Molecular biology: compare DNA (nucleotide sequence) or proteins (amino acid sequence)

  33. Evolution Evidence • Molecular biology: compare DNA (nucleotide sequence) or proteins (amino acid sequence) • Similarity reflects relatedness.

  34. Evolution Evidence • Ex use: What is a quagga? • Native South Africa • Extinct by 1880s (hunting) One of 23 skins in museums Quagga stallion (drawing) Only quagga photographed alive (in London Zoo, 1870)

  35. Evolution Evidence Przewalski’s horse from Mongolia • Horse or zebra? Plains zebras from South Africa

  36. Evolution Evidence • DNA from museum skin: quagga type of zebra

  37. Evolution Evidence • Experimental evidence • Natural selection: peppered moths (England) • Dark and light forms (1 gene) Dark moth Light moth

  38. Evolution Evidence • Experimental evidence • Final twist: Pollution controls changing balance again!.

  39. Evolution Evidence • Experimental evidence • Natural selection: Galapagos Islands

  40. Evolution Evidence • Experimental evidence • Natural selection: Galapagos islands • Finch species eats seeds. Galapagos Islands : telephoto view from the space shuttle!

  41. Evolution Evidence • Experimental evidence • Bill size changes: food supply changes with climate.

  42. Evolution Evidence • Experimental evidence • Guppy experiment: guppies native to Trinidad

  43. Evolution Evidence • Experimental evidence • Guppy experiment • Involves sexual selection: males colorful. Attractive to females but helps predators find males!

  44. Evolution Evidence • Experimental evidence • Experiment: Move guppies to low predator site. Male tails became larger/more colorful

  45. Evolution Evidence • Artificial selection: Humans cause evolution by our activities • Intentional: Control breeding to change traits

  46. Evolution Evidence • Intentional: Control breeding to change traits • Ex: dog breeds.

  47. Evolution Evidence • Natural selection also caused evolution of dog-like species

  48. Evolution Evidence • Intentional artificial selection • Ex, wild mustard now cabbage, broccoli, kohlrabi, brussel sprouts, cabbage, cauliflower, etc. Wild mustard Foods you should eat more of!

  49. Evolution Evidence • Artificial selection: Humans cause evolution by our activities • Unintentional: Usually species we try to kill! • “Antibiotic resistance”: bacteria evolve to be unaffected by antibiotics

  50. Evolution Evidence • Ex, bacterium causes tuberculosis (TB) • Some strains now resistant to most antibiotics. Chest x-ray of TB patient TB bacteria

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