1 / 22

Evolution: Change Over Time

Evolution: Change Over Time. Evolution: Change Over Time. The Evidence. The Evidence. Evolution: Change Over Time. Evolution: Change Over Time. The Evidence. The Evidence. Fossil Record. Defined : Collection of every known fossil Most fossils found in sedimentary rock

ranee
Download Presentation

Evolution: Change Over Time

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Evolution: Change Over Time Evolution: Change Over Time The Evidence The Evidence Evolution: Change Over Time Evolution: Change Over Time The Evidence The Evidence

  2. Fossil Record • Defined: Collection of every known fossil • Most fossils found in sedimentary rock • Age determined by depth • Law of Superposition: new rock forms on top of older rock • A.k.a. Relative Dating • Evidence Conclusions: • 1) Newer fossils are more complex • 2) Common ancestors: similarities between ancient & modern life

  3. AKA: Transition Fossils Archaeopteryx: shares both bird & reptile features Basilosaurus: shares whale & land mammal features Tiktaalik: shares fish & amphibian features Evidence Conclusion : Indicates common ancestry Missing Link Fossils Whale Evidence Long spine Found in dried up oceans Amphibian evidence Eyes on top of head Wrist bones Reptile Evidence Teeth Bony tail Fish evidence Scales Fins Found in dried-up oceans Land Evidence Wolf-like teeth Hind legs Bird Evidence Wishbone Feathers

  4. Comparing old fossils to modern life shows change Ancient Kelp Modern Kelp

  5. Helps determine age of fossils. More accurate than relative dating. Isotopes: atoms of the same element with differing neutrons Ex: 12C and 14C 12C = 6 protons + 6 neutrons 14C = 6 protons + 8 neutrons Organisms collect carbon throughout their lifetime. When organism dies: 14C starts to decay into 14N at a known rate (half-life) Fossil age determined by comparing ratio of C to N Wider ratio = older sample Radiometric Dating Both are Carbon

  6. Dating Fossils

  7. island species most closely resemble nearest mainland species • populations can show variation from one island to another Geography • The study of geography provides evidence of evolution.

  8. Embryo Development • Different species show similar development patterns • Different body plans become noticeable later in development • Evidence Conclusion : Indicates common ancestry

  9. flipper arm leg wing Homologous Structures walking flight grasping swimming • Defined: similar body structures with very different functions • Different environments lead to adaptations • Ex: The forelimbs of animals • Evidence Conclusion : Indicates common ancestry

  10. Human hand Mole foot Bat wing Fly wing • Homologous structures are different than analogous structures • Analogous structures have similar functions but different structures. • Analogous structures are not evidence of a common ancestor.

  11. Vestigial Structures • Defined: Organs or structures which have lost most or all their original function • Vestigial Human Parts: • Gill slits = once used to breath oxygen in water • Yolk sac = once used to nourish developing embryo • Tailbone = once used for balance • Appendix = once used to digest plants • Wisdom teeth = once used to grind plant tissue • Evidence Conclusion : Indicates common ancestry

  12. Human Embryo w/ Vestigial Structures

  13. Pythons have tiny femurs (leg bone)

  14. Biochemical Evidence • DNA, RNA, proteins compared • Genetic code same for most life • More related species have more similar biochemistry • Evidence Conclusion : Indicates common ancestry

  15. Resistant Organisms • Constant creation of chemicals for human use is eliminating the “unfit” (invading)organisms • Ex: Antibiotics eliminating unfit bacteria • Ex: Pesticides eliminating unfit pests • Ex: Antivirals… • Ex: Fungicides… • Allows resistant to survive and reproduce

  16. Most bacteria killed Strong Survive Bacterial Resistance Strong Reproduce

  17. Antibiotic Resistance penicillin vancomycin ampicillin Amoxycillin tetracyclin Which antibiotics would successfully treat this infection?

  18. Review • How does antibiotic and pesticide resistance show natural selection? • How do the following lines of evidence show change over time? • Fossils • Homologous structures • Vestigial structures • Resistant organisms • Embryo development • Biochemical (molecular) evidence • Fossil age can be determined two ways. What are they? • Which type of anatomical structures do not show evidence of common ancestry?

More Related