1. what is vestigial?
    a useless orrudimentary version of a body part that has animportant function in a related species
  2. Vestigial Features as evidence of evolution
    • in humans:
    • - human tailbone (coccyx)
    • - plica seilunaris: vestigial form of the prtective nicitating membrane found in some animals
    • - arrectores pilorum: tiny muscle that cause goosebumps
    • - wisdom teeth: used to grind plant
    • - vermiform appendix: connected to intestine and houses bacteria which aid in breakdown of plants (also a reduced feature in other meat eating animals)

    • in whales:
    • - femur attached to pelvis (indicates the whales once had hind legs)
  3. Fossils
    any trace of an organism that lived at somepoint in the past
  4. Law of Succession
    correspondence between fossil forms and extant species living in a given region
  5. Transitional Fossils as evidence for evolution
    • - provides evidence of common ancestry among extant taxa
    • e.g.: - fish to amphibian transition (Tiktaalik roseae --> Ichthyostega)
    • - transition to flight (Archaeopteryx - has feathers with dinosaur traits like sharp teeth, three clawed fingers, bony tail)
    • - law of succession demonstrated by fossil glyptodont --> pygmy armadillo (Argentina) and Diprotodon --> wombats (Australia)
  6. homology
    • from the Greek word for “to agree”
    • have similar structures b/c of a share common ancestor
  7. anaologous structures
    • structures that appear similar but are not the result of a shared common ancestor
    • aka convergent
  8. Homology as evidence for evolution
    - All life uses DNA or RNA as the genetic material to pass characteristics from one generation to the next

    - Basic physiology is the same across life– Example: glycolysis, which converts glucose to pyruvate, is nearly universal

    - Genetic code is nearly universal: There are few exceptions to the genetic code• e.g., mitochondrial code slightly different from “universal” code– Those exceptions show homology amongst themselves
  9. other evidence of evolution
    - Biogeography: present-day species distributions reflect speciation history from shared ancestors
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