genbio 3

• geologic time scale - a system used by scientist to describe the timing and relationships between periods
• primitive life -cannot pinpoint where life began. 3.5 billion years ago
• eons

  1. hadean
  2. archaean
  3. proterozoic
• hadean -first ocean, earliest
• archaean -first single celled organism and ecosystem. formation of continentss
• proterozoic -multicellular life evolved, Pangaea and panthalassa
• Panthalassa is divided into 5:

  1. pacific
  2. antartic
  3. atlantic
  4. arctic
  5. indian
• cambrian period -cambrian exploson
• cambrian period -aquatic animals, (mollusk,brachiopods, trilobites) invertebraes, phytoplankton
• ordovician -ice caps cover n. africa, ancestors of squid and octopus,jawless fish appeared
• sillurian -corals develop, lands plants appears, SPIDERS! EVOLVE
• Devonian -age of fishes, animals began to invade land (lungfish -1st vertebrates) amphibians evovled
• carboniferous -life expanded over continents, pennyslvanian and mississippian, small reptiles develop, huge dragonfly
• permian -reptiles are the dominant land species
• mass extinction -climate change from continental drift
• mesozoic

  Triassic period -first, insects,reptiles, dinosaurs,mammals,turtle,crocodile,forest
• mesozoic

  jurassic period - first bird (archeopteryx)

  first flying reptile (pterosaurs)

  breaking up of pangaea\
• mesozoic

  cretaceous -continents move towards present location. widespread volcanic activity, nagaway away na yung mga flying reptiles FIST SNAKESSSSSSSSSSSSSSS APPEARED
• cenozoic


  tertiary period -himalayans and rocky mountains are formed, FIRST GRASSES APPEARED, ancestors of human evolved
• cenozoic


  quaternary -modern humans (homosapiens)