BIOL 1001 Lecture Notes - Lecture 1: Panthalassa, Tethys Ocean, Radionuclide
Document Summary
(cid:0) chapter 20. 2 history of life on earth. The universe began with the big bang about 13. 7 bya. The earth is 4. 55 billion years" old. 4 bya the earth cooled enough for outer layers to solidify and oceans to. 4 bya to 3. 5 bya . first life on earth form. Bio life or relating to living organisms. Micro - small; too small to be seen with the naked eye. Symbiosis a close association between two organisms. Geological time scale four eons: beginning of the earth 4. 55 bya ago to present, phanerozoic, proterozoic, archean, hadean (oldest) Near end of ordovician, devonian, permian, triassic, and cretaceous periods. Geologictime periods are often based on these events. Fossils recognizable remains of past life on earth. Many rocks with fossils are sedimentary: sediments pile up and become rock, organisms buried quickly and hard parts replaced by minerals. Older rock is deeper and older organisms are deeper in the rock bed.
