ZOOL 224

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  1. What periods were in the Phanerozoic Era?
    Cenozoic, Mesozoic, and Paleozoic
  2. What was a notable point about the Cenozoic period?
    Had the most diversification within Vertebrets
  3. What was a notable point about the Paleozoic period?
    Vertebrets originated around this time
  4. How are Linnean Ranks based?
    On morphological structures
  5. Cladistics
    Rules for making classifications
  6. How are taxa defined and organisms classified?
    Based on their evolutionary relationships
  7. Phylogeny
    Evolutionary relationships of members within a taxon
  8. What are phylogenies made of?
  9. Cladogram
    System of dichotomous branches developed from shared traits
  10. Are cladograms concrete?
    They're hypothesis
  11. How are clades formed?
    Through homologous traits
  12. Homologous Trait
    Trait shared due to common ancestry
  13. Principle of Parsimony
    Take the simplest explanation (least character state changes) to explain shared traits.
  14. Monophyletic Group
    Group containing common ancestor and all decendents
  15. Paraphyletic group
    Group that excludes some decedents due to divergent evolution
  16. Divergent Evolution
    Taxa or group acquiring derived characteristics separating it from it's initial group into a new species.
  17. Polyphyletic Group
    Groups with similar traits that could have evolved independently (Bats and birds are polyphyletic)
  18. Analagous
  19. Convergent Evolution
    Two species or groups that evolved independently but developed similar traits
  20. Synapomorphy
    Shared derived traits that define the taxon you're looking at (4 walking legs are synapomorphic for tetrapods)
  21. Apomorphy
    Derived Trait
  22. Autapomorphy
    Derived trait present in only one taxon (hair only on heads for humans)
  23. Plesiomorphy
    Traits of the ancestors of the common ancestor (vertebrae and hinged jaws are plesiomorphic to tetrapods)
  24. Symplesiomorphy
    A shared ancestral trait by 2+ taxa
  25. Outgroup
    Reference group that is closest related to the ones you're studying. Contain all ancestral but no derived traits.
  26. Sister Group
    Group most closely related to taxon under analysis (closest outgroup, look on other end of prong)
  27. Stem Group
    Extinct species with some derived traits of the crown group (closer related than sister group and all are paraphyletic)
  28. Crown Group
    Living (and some extinct) species with all derived traits.
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ZOOL 224
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