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Evolution Part 2

Evolution Part 2. BIOL 1407. Evolutionary Fitness. Darwin’s concept: An organism is more “fit” if it has more offspring that successfully reproduce compared to others in the population. Photo Credit: Eigenes Werk, 2008, Wikimedia Commons. Evolutionary Fitness.

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Evolution Part 2

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  1. EvolutionPart 2 BIOL 1407

  2. Evolutionary Fitness • Darwin’s concept: An organism is more “fit” if it has more offspring that successfully reproduce compared to others in the population Photo Credit: Eigenes Werk, 2008, Wikimedia Commons

  3. Evolutionary Fitness • More fertile offspring = Higher Fitness Photo Credit: Larry Ridenhour, Bureau of Land Management, 2005

  4. Evolutionary Fitness • Fitness ≠ Survival • Fitness ≠ Stronger • Fitness ≠ Healthier • Fitness ≠ Smarter • Fitness ≠ Better • Photo Credit: Jeff Kubina, 2004, Wikimedia Commons

  5. Evolutionary Fitness FITNESS = MORE OFFSPRING! Photo Credit: B.navez, 2007, Wikimedia Commons

  6. Evolutionary Fitness • Fitness comes down to leaving more copies of your genes in future generations than others • Photo Credit: Harlequeen, 2007, Wikimedia Commons

  7. Inclusive Fitness • Inclusive fitness = your fitness + fitness of family members • Directly and indirectly leaving copies of your genes • Photo Credit: Ltshears, 2006, Wikimedia Commons

  8. Florida Scrub Jays • Young jays help their parents raise siblings • May forego reproducing for up to five years • Some never get to reproduce • Photo Credit: VvAndromedavV, 2008, Wikimedia Commons

  9. Florida Scrub Jays • Still have fitness  their genes are present in the siblings they helped raise

  10. Adaptations • Characteristics that increase fitness in a particular environment • Can be: • Structures • Biochemical reactions • Behaviors • Anything under genetic control that provides some sort of advantage

  11. Adaptations • A successful adaptation in one environment may not be successful in a different environment. • Photo Credit for desert: Jörn Napp, 2007, Wikimedia Commons • Photo Credit for Prairie: Katy Prairie Conservancy, 2008, Wikimedia Commons

  12. Walrus Adaptation • Thick blubber is an adaptation for cold Arctic ocean conditions. • In warmer waters, they overheat and die • Photo Credit: NOAA, 2005, Wikimedia Commons

  13. Adaptation Example: Railroad Vine • Often seen on Texas beaches • Live on sand dunes • Constantly shifting sand • Little water • High salt levels. • Photo Credit: South Siesta Key Beach Restoration

  14. Railroad Vine • Long runners stabilize sand • Soil accumulates around roots • Stabilizes dune • Photo Credit: UNK Vieques Field Trip 2008

  15. Example: Railroad Vine • Other plants move onto stable dunes • Railroad vines cannot compete successfully in other environments. • Photo Credit: National Park Service, Padre Island, http://www.nps.gov/archive/pais/pphtml/photogallery.html

  16. The Great Potoo • Night: Fly and catch insects • Day: sleep on branches • Camouflage used for protection • Video:http://www.youtube.com/watch?v=MK6nlsOZpuU • Photo Credit: Tom Davis

  17. The Great Potoo • Adaptations: • Plumage coloration • Body position • Eyelids • Photo Credit: Tom Davis

  18. Evidences of Evolution • Fossil Record • Biogeography • Comparative Anatomy • Comparative Embryology • Molecular Evidence

  19. Fossils • A window into evolutionary history • Only way to see what some organisms looked like in the past • Photo Credit: Doyle Cross at Texas Memorial Museum, UT Austin

  20. Pterosaur FossilPhoto Credit: Doyle Cross at Texas Memorial Museum, UT Austin

  21. Pterosaur Wing DetailsPhoto Credit: Doyle Cross at Texas Memorial Museum, UT Austin

  22. Fossil Record • Gaps in fossil record • In cases of major structural changes: • Evolve in step-by-step fashion? • Evolve suddenly (one step)? • With gaps, you can’t be sure

  23. Transitional Fossils • Demonstrate a step-by-step transition from an ancestral form to modern forms • Photo Credit for Tiktaalik rosae: ArthurWeasley, 2007, Wikimedia Commons • Building Tiktaalik Video: http://www.youtube.com/watch?v=MkOy1XU0cbY • And, for fun, enjoy the music video: http://www.youtube.com/watch?v=B9h1tR42QYA

  24. Whale Transition • Fossils: Pakistan, Egypt, North America • Four-legged terrestrial ancestors  Whales • Hind limbs: Legs  Vestigial bones • Front limbs: Legs  Flippers • Ankle bones: Similar to hippos & relatives

  25. Biogeography • Study of distribution of organisms: • Where are they located? • Why are they there? Horseshoe Crabs Distribution Map Credit: University of Delaware College of Marine and Earth Studies and the Sea Grant College Program http://www.ocean.udel.edu/horseshoecrab/history/pastpresent.html

  26. An Example: Ratites • Large, flightless birds • Southern Hemisphere • Photo Credit: Richard001, 2007, Wikimedia Commons

  27. Living Ratites • Ostrich (Africa) • Rheas (South America) • Emus (Australia) • Cassowaries (Australia and Papua New Guinea), • Kiwis (New Zealand) • Photo Credit: Paul IJsendoorn, 2007, Wikimedia Commons

  28. Extinct Ratites • Moas (New Zealand) • Elephant Bird (Madagascar) • Photo Credit for Moa drawing: Frederick William Frohawk, 1907, Wikimedia Commons

  29. Evolution of Ratites • Common ancestor evolved on Gondwana • Gondwana  Southern Continents • Picture Credit: USGS image from Wikimedia Commons

  30. Comparative Anatomy • Similarities and differences in structure Photo Credits: Vassil (2007, Crocodile eye) and Rainer Zenz (2006, Cuttlefish eye), Wikimedia Commons

  31. Homologous Structures • Similar due to shared ancestry

  32. Analagous Structures • Similar lifestyles but different ancestry

  33. Comparative Embryology • Similarities and differences in development

  34. Comparative Embryology • Some similarities only visible during early development • Completely obscured in later stages Photo Credits: Fir0002, 2008, Wikimedia Commons (Chick); Michele Cross, 2007 (Human baby)

  35. Comparative Embryology • Click on this link and play the video: http://www.pbs.org/wgbh/evolution/library/04/2/l_042_02.html Photo Credit: Dr. Katharine Lewis, University of Cambridge, School of the Biological Sciences, http://www.pdn.cam.ac.uk/staff/lewis/

  36. Molecular Evidence • Comparisons of protein or DNA sequences • Can show evolutionary relationships among widely divergent organisms Protein Sequence Credit: Miguel Andrade, 2006, Wikimedia Commons

  37. Molecular Evidence • Distinguish homologous from analogous structures • Read about Giant Pandas at:http://www.giantpandaonline.org/naturalhistory/phylogen • Photo Credit: Jeff Kubina, 2004, Wikimedia Commons

  38. Molecular Evidence

  39. The End Unless otherwise specified, all images in this presentation came from: Campbell, et al. 2008. Biology, 8th ed. Pearson Benjamin Cummings.

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