Biology Notes 5-2-08

Biology Notes 5-2-08 - -large meteorite, -mass extinction...

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Biology Notes May 2, 2008 The history of life on Earth All of these change over time: -Location of seas and continents (continental drift and sea level changes) -Amount of oxygen and carbon dioxide -Volcanic and mediorite activity -Climatic conditions (warm/wet, cool/dry) Change in position of continents: -Influences ocean circulatory patterns, sea level and global climate Earth’s atmosphere has also changed: -Early atmosphere probably contained little or no free oxygen -Oxygen increased when cyanobacteria evolved the ability to use water as a source of H+ ions in photosynthesis, by releasing oxygen gas as a product. Fig. 21.5 and 21.6 in book Volcanoes and Meteors: -End of Permian (275 mya): -collisions of continents, high volcanic activity -Cooling, largest glacial period. -Extinction of about 95% of all species on earth. -End of Cretaceous (65mya):
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Unformatted text preview: -large meteorite, -mass extinction of large vertebrates (dinosaurs) and mollusks Evolution:-1.8 bya: eukaryotes evolve-1.2 bya: fungi, animals, plants, algae diverge-900 mya: soft-bodied animals, algae-Many animals required soil to evolve so there had to be some decaying plant material available for them to show up. (Fig. 21.19 in book) Diversity:-Natural selection is the primary mechanism that has shaped the great diversity of life on earth.-This vast diversity is seen in the genetic, morphological, physiological, ecological, and behavioral adaptations found across living organisms.-There is grandeur in the view of life From so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved. - Darwin...
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This note was uploaded on 05/02/2008 for the course BIOL 102 taught by Professor Hill/smith during the Spring '08 term at Idaho State University.

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