Animal Evolution

  1. Evolution
    Change in genetic structure of a population of organisms over time
  2. Population
    Group of the same species that occupies a given area
  3. Species
    Group of organisms with similar characteristics that can interbreed and produce viable offspring
  4. Artificial Selection
    forced breeding
  5. Natural Selection
    The difference in reproductive success of individuals based on genetic traits
  6. Where do traits come from?
    Random changes in DNA from mating/mutations
  7. Darwin's observations (2)
    • Closely related organisms in different environments are different
    • Unrelated organisms in similar environments are similar
  8. Darwinian Evolution (4)
    • Heritable Natural Variation
    • Limited resources
    • Those with traits best able to take advantage of resources are more likely to reproduce
    • Species related by common descent
  9. What does natural selection lead to over time (generations)?
    Leads to new adaptations and species
  10. What Darwin did NOT do:
    • Understand HOW traits were passed on
    • "Survival of the fittest"
  11. Evidence of Evolution (6)
    • Fossils
    • Homologous Structures
    • Comparative embryology
    • Vestigial Structure
    • Analogous Structures
    • Field Studies
  12. Homologous Structures
    Parts of the body that are the same but take on different forms/ functions in different animals
  13. Vestigial Structures
    Old structures that remain in organisms (human tail), evidence of past evolution
  14. Analogous Structures (2)
    • Structures that do not come from related organisms but they look similar
    • Arise more than once
  15. Importance of evolution (4)
    • Medical Purposes
    • Food
    • Human Interactions
    • Natural Resources
  16. Microevolution (2)
    • Changes in gene frequencies in a population
    • Shorter time periods
  17. What causes microevolution? (3)
    • Natural Selection
    • Mutations
    • Gene flow (migration)- moving in and out of a population
  18. How does Microevolution work?
    It works by changing a population "directionally"
  19. Macroevolution (4)
    • Speciation
    • Longer time period
    • Forms new species
    • Isolation
  20. Allopatric Speciation
    Populations diverge from each other over time
  21. What causes Allopatric Speciation?
    Vicariance & Founder Events
  22. Vicariance
    Due to climate, geology, physical changes to habitat
  23. Founder Events
    Dispersal to new habitats, common on islands
  24. Sympatric Speciation (3)
    • No geographic isolation, but reproductive barriers form
    • Specialization to specific foods, habitats
    • Changes in behavior
  25. How does evolution occur? (3)
    • Change in numbers
    • "forced" breeding
    • "natural" breeding
Card Set
Animal Evolution
evolution of animals, as well as the role charles darwin had in evolution