bio112 exam2

  1. homology
    a similar structure, similar development, or similar genetics among organisms that exist because they share a common ancestor
  2. vestigial structures
    remnants of structures inherited from a common ancestor, that no longer serves a clear function in the organisms
  3. biogeography
    study of geographic distribution of species (living and extinct)
  4. convergent evolution
    • organisms have similar characteristics even though they are not closely related but instead they have evolved similar adaptations because they occupy similar nitches
    • 2 different species from 2 different lineages independently evolved similar characteristics because they occupy simlar environments
  5. Taxonomy
    • the process of describing, naming, and classifying extant organisms
    • those that are living today
  6. systematics
    • a field of study that examines the biological diversity and evolutionary relationships among organisms, both extant and extinct
    • focus is on pattern and process
    • based on homology
  7. phylogeny
    • the evolutionary history of a species (or group of species)
    • use the tools of systematics to propose a phylogeny
  8. phylogenetic tree
    a diagram that describes the evolutionary relationships among species based on information gathered by systematists
  9. cladogram
    hypothesis that is proposed, tested, and refined
  10. monophyletic
    • a taxon that is a clade
    • what we are aiming for
    • ex mammals
  11. paraphyletic
    a group that contains a common ancestor and some (but not all) of its descendants
  12. polyphyletic
    a group that does not contain the most recent common ancestor
  13. cladistics
    • compare homologous traits = character
    • each character/trait can exist on 2+ character states
  14. molecular clocks
    • most mutations are neutral
    • they have no impact on the organism, if neutral mutations occur at a relatively constant rate, can use them as a clock to measure evolutionary time
  15. cladogenesis
    the splitting or diverging of a population into 2 species
  16. clade
     or monophylum is a group consisting of an ancestor and all its descendants, a single "branch" on the "tree of life
  17. synapomorphy
    shared/together traits
  18. apomorphy
    • a derived character
    • A novel evolutionary trait that is unique to a particular species and all its descendants and which can be used as a defining character for a species or group in phylogenetic terms.
  19. symplesiomorphy
    • shared-primitave trait
    • In cladistics, a symplesiomorphy or symplesiomorphic character is an ancestral trait shared by two or more taxa. A plesiomorphy refers to the ancestral trait on its own, usually in reference to another, more derived trait.
  20. autapomorphy
    In cladistics, itis a distinctive anatomical feature, known as a derived trait, that is unique to a given terminal group. That is, it is found only in one member of a clade, but not found in any others or outgroup taxa, not even those most closely related to the group
  21. shared primitive character
    a character that is shared by species beyond the taxon of interest
  22. shared derived character
    a character (feature) shared by all the species in a group but not by any species outside that group synonym: synapomorphy
Card Set
bio112 exam2
bio112 exam2