1 / 43

EVIDENCE THAT SUPPORTS EVOLUTION

EVIDENCE THAT SUPPORTS EVOLUTION. Pillar #1: The Fossil Record. What is a fossil?. The remains or evidence of an organism Fossilized bone, wood, shell, or dung Casts, imprints, or molds Amber or tar entrapments Imprints of footprints or borings. Fossil Facts.

nubia
Download Presentation

EVIDENCE THAT SUPPORTS EVOLUTION

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. EVIDENCE THAT SUPPORTS EVOLUTION

  2. Pillar #1: The Fossil Record

  3. What is a fossil? • The remains or evidence of an organism • Fossilized bone, wood, shell, or dung • Casts, imprints, or molds • Amber or tar entrapments • Imprints of footprints or borings

  4. Fossil Facts • Most are found in sedimentary rock. • The fossil record shows that life has changed over time. • The fossil record is very incomplete. • Fossils give us a glimpse into the morphology of organisms now extinct.

  5. Interpreting Fossil Evidence • Relative Dating – the age of a fossil is estimated by comparing it to other fossils in rock layers • Rock layers form in order of age – the oldest layers are on the bottom

  6. Interpreting Fossil Evidence • Radioactive Dating – using radioactive decay to assign absolute ages to fossils • A half-life is the length of time required for ½ of the radioactive atoms in a sample to decay

  7. If 100 g of Carbon-14 decays until only 25 g of carbon is left after 11, 460 years, what is the half-life of carbon-14?

  8. Thallium-208 has a half-life of 3.053 minutes. How long will it take for 120 g to decay to 7.5 g?

  9. Gold-198 has a half-life of 2.7 days. How much of a 96g sample will be left after 8.1 days?

  10. Archaeopteryx (late Jurassic- 150 MYA)

  11. Transitional Whale Fossils

  12. Pillar #2: Structural Similarities Among Organisms

  13. Homologous Structures • Structures that have similar characteristics but may or may not have similar functions. • Ex: forearms of vertebrates

  14. Vestigial Structures • Structures that are diminished in size and/or function. • Ex: eyes of moles

  15. Homologous & Vestigial structures give evidence of DIVERGENT EVOLUTION. • They suggest that descendents DIVERGED (became different) as the distance from the common ancestor increased.

  16. Analogous Structures • Structures with the same function in organisms that are not closely related. • Ex: the wings of birds and the wings of insects. • Ex: thorns of the rosebush and the quills of the porcupine.

  17. Analogous structures suggest CONVERGENT EVOLUTION. • Organisms did not descend from a common ancestor, they independently evolved similar adaptations to survive in similar environments.

  18. Pillar #3: BiogeographyThe Geographic Distribution of Organisms

  19. What is biogeography?The study of. . . • Where species live on earth and why • How organisms are adapted to their environment

  20. Pillar 4: Embryological Similarities

  21. Scientists study the • Morphology of Embryo • The fate of particular embryonic tissue

  22. Pillar #5: Molecular Similarities

  23. All organism have… • The same “Genetic Code” • 4 DNA nucleotides • Same 64 mRNA codons that code for the same amino acids • Ribosomes as the site of protein synthesis • ATP as the energy currency • Plasma membranes that consist of a phospholipid bilayer w/ imbedded proteins

  24. Compare common proteins • Count and compare how many of the amino acids differ • Compare the nucleotide sequences of DNA • the closer the DNA sequences, the more closely related the organisms are.

  25. Pillar #6: Direct Observation

  26. Examples of OBSERVED Natural Selection • DDT Resistant Mosquitoes • Antibiotic Resistant Drugs • Darwin’s Finches

More Related