BIOL 2200 Lecture Notes - Lecture 8: Cell Membrane, Archaea, Phanerozoic
3 Feb 2017
School
Department
Course
Professor
Document Summary
If earths history is represented by a clock, the genus homo, represents less than one minute: homo sapiens represent only a few seconds. Timeline: origin of solar system 4. 6 bya, oldest prokaryote cells 3. 5 bya, oldest eukaryotic cells 1. 8 bya, oldest multicellular eukaryotes 1. 2 bya, cambrian explosion 540 mya. Circular dna: eukaryotes more complex cells. Lots of change differentiation of earth into mantle, crust, core. No fossils present from this period as of yet. Formation of the atmosphere from volcanic gases. Water vapor condensed into acidic lakes: archean eon (3. 85 2. 5 bya) The evolution of photosynthesis was critical to further evolution because it led to the development of cellular respiration. Oxygen producing prokaryotes (related to cyanobacteria: proterozoic eon. Eukaryotes occur for the first time about 1. 8 bya (cells with nuclear envelopes, organelles) Multicellular eukaryotes begin to develop about 1. 2 bya. Soft organisms need certain conditions in order to fossilize. Sharp rise in atmospheric oxygen, about 2. 5 mya.
