Evidence for evolution powerpoint


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Evidence for evolution powerpoint

  1. 1. Evolution: Evidence SC.912.L.15.1 Explain how the scientific theory of evolution is supported by the fossil record, comparative anatomy, comparative embryology, biogeography, molecular biology, and observed evolutionary change
  2. 2. Types of Evidence we will be covering <ul><li>Fossil Records </li></ul><ul><ul><li>Transitional fossils </li></ul></ul><ul><li>Comparative Anatomy </li></ul><ul><ul><li>Homologous Structures </li></ul></ul><ul><ul><li>Analogous Structures </li></ul></ul><ul><li>Vestigial Structures </li></ul><ul><li>Biogeography </li></ul>
  3. 3. Fossil Records <ul><li>Fossils support the idea of evolutionary progression. </li></ul><ul><li>By looking at fossils Paleontologists/zoologists can: </li></ul><ul><ul><li>Identify extinct animal species </li></ul></ul><ul><ul><li>Follow the path of evolution through different stages of development </li></ul></ul><ul><ul><li>Evolution of the Whale </li></ul></ul>
  4. 4. Key Points of the Fossil Record <ul><li>Provides evidence of evolution from one species to another </li></ul><ul><ul><li>Shows ancestral intermediates </li></ul></ul><ul><li>Only hard tissue is preserves </li></ul><ul><li>Fossil Formation </li></ul>
  5. 5. Transitional Fossils <ul><li>FLASH CARD ALERT: </li></ul><ul><ul><ul><li>TRANSITIONAL FOSSIL: fossils that show transitions in evolution. </li></ul></ul></ul><ul><li>Transitional fossils are RARE findings </li></ul><ul><ul><li>Small proportion of organisms become fossils </li></ul></ul><ul><ul><li>Many fossils represent dead evolutionary branches </li></ul></ul>
  6. 6. Support: Comparative Anatomy <ul><li>Homologous Structures: Similar features found in different species that are derived (come from) a common ancestor </li></ul><ul><ul><li>Ex. Tetrapod limbs, fur, lungs </li></ul></ul><ul><li>Bone formation: developmental and evolutionary similarities </li></ul><ul><li>Evidence of intermediates </li></ul>
  7. 8. Analogous Structures <ul><li>FLASH CARD ALERT: </li></ul><ul><li>Analogous Structures: a trait or an organ that appears similar in two unrelated organisms </li></ul><ul><li>Happens because of convergent evolution: </li></ul><ul><ul><li>FLASHCARD ALERT: CONVERGENT EVOLUTION: Species evolve in similar environments and have similar environmental stressors/survival factors </li></ul></ul>
  8. 9. Analogous Structures
  9. 10. Vestigial Structures <ul><li>Vestigial Structures : characteristics found in existing species that have no known function </li></ul><ul><li>Provide evidence of common ancestry </li></ul><ul><li>As species evolve their structures change </li></ul><ul><ul><li>Two things will happen </li></ul></ul><ul><ul><ul><li>Species will adapt the organ/structure to a new use </li></ul></ul></ul><ul><ul><ul><ul><li>penguin </li></ul></ul></ul></ul><ul><ul><ul><li>The organ or structure will no longer have a use </li></ul></ul></ul><ul><ul><ul><ul><li>Whale pelvis/snake feet. </li></ul></ul></ul></ul>
  10. 11. Useless for Flying but excellent for swimming
  11. 12. Vestigial Structures <ul><li>Stubs on pythons, boas, and other snakes </li></ul><ul><ul><li>Ancestral legs </li></ul></ul><ul><ul><ul><li>No known </li></ul></ul></ul><ul><ul><ul><li>function </li></ul></ul></ul><ul><li>Useless Vestigial structures are BETTER sources of evidence for evolution </li></ul>
  12. 13. Amphiuma
  13. 15. Flightless Wings
  14. 16. Plica semilunaris
  15. 17. CFU: <ul><li>What is the major difference between analogous and homologous structures? </li></ul><ul><li>What structure is the best evidence of evolution: analogous, homologous or vestigial </li></ul><ul><li>What kind of tissue/part of an animal is preserved in fossils? </li></ul><ul><li>What type of fossils are paleontologists most interested in? </li></ul><ul><ul><li>Why are they hard to find? </li></ul></ul>
  16. 18. Comparative Embryology <ul><li>Incredible similarities in embryos of different species provides evidence of common ancestor </li></ul><ul><ul><li>Patterns of embryo development are also important. </li></ul></ul>
  17. 19. Biogeography <ul><li>Zoologists seek to understand how very closely related species ended up in completely different parts of the world </li></ul>
  18. 20. Support for Pangaea
  19. 21. Key Point of Biogeography <ul><li>Seeks to answer the question: how/why different but similar species exist in similar yet separate parts of the world </li></ul><ul><li>Can be explained by geological changes, migrations, convergent evolution </li></ul><ul><li>Support ideas of common ancestor and Pangaea </li></ul>
  20. 22. EVOLUTION CFU <ul><li>What are the five steps of evolution? </li></ul><ul><li>How does the environment affect the process of evolution? </li></ul><ul><li>Adaptations help the organism: </li></ul><ul><li>The three types of structures that support evolution are: </li></ul><ul><li>Paleontologists are excited to find what kind of fossil and why? </li></ul>