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2011-01-19 13:04:12
History Life on Earth

1520 Chapter 25
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  1. Define macroevolution
    the pattern of evolution over large time scales
  2. Define protobiont
    A collection of abiotically produced molecules surrounded by a membrane or membrane-like structure
  3. Define Radiometric Dating
    a method for determining the absolute ages of rocks and fossils, based on half-life of radioactive isotopes
  4. Define Half-life
    the amount of time it takes for 50% of a sample of a radioactive isotope to decay
  5. Define geologic record
    The division of Earth's history into time periods, grouped into 3 eons- Archaean, Proterozoic, and Phanerozoic
  6. Define Stromatolite
    layered rock that results from the activities of prokaryotes that bind thin films to sediment together
  7. Define endosymbiosis
    a model taht posits that mitochondria and plastids were formally small prokaryotes that began living within larger cells
  8. Define Serial endosymbiosis
    a model that posits that mitochondria evolved before plastids through a sequence of endosymbiotic events
  9. Cambrian Explosion
    Burst of life, and diversity, hard bodied animals appear
  10. Define Continental Drift
    the slow movement of the contenental plates across Earth's surface
  11. Define Pangaea
    The supercontinent that formed near the end of the paleozoic era, when plate movements brought all fo the landmasses of Earth together
  12. Define Mass Extinction
    When large numbers of species become extinct throuout earth
  13. Define Adaptive Radiations
    Periods of evoluionary change in which groups of organisms form many new species whose adaptations allow them to fill vacant ecological roles in their communities
  14. Define heterochrony
    Evolutionary change in the timing or rate of an organism's development
  15. Define paedomorphosis
    The retention in an adulgt organism of the juvenile features of its evolutionart ancestors
  16. Define homeotic genes
    Any of the master regulatory genes that control placement and spatial organization of body parts in organisms by controlling the developmental fate of groups of cells