Evolution overview 2010

Evolution overview 2010 - EVOLUTION OVERVIEW In talking...

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Unformatted text preview: EVOLUTION OVERVIEW In talking about the fossil past, we need to understand that the world did not always look the way it does now In particular, the continents used to be in different locations, with different climates and vegetation The significance for us is that the environment was changing A changing environment means there was natural selection, resulting in variation Vocabulary: bya = billion years ago mya =million years ago ya = years ago Scientific notation: Genus is always capitalized Species is never capitalized Both are italicized when typed/printed; when handwritten, they are underlined Genus may be abbreviated when understood. Homo sapiens H. sapiens Estimate age of universe about 15 billion years. Formation of earth almost 4.6 bya First life on earth 3.8 bya organic molecules. By 3.6 bya, first single-celled photosynthesizing organisms By about 2 bya, oxygen in atmosphere Around 1 bya, the beginning of sexual reproduction Theory of Plate Tectonics: the Earths outermost layer is fragmented into a dozen or more plates that move Thus, we have continental drift (http://www.ucmp.berkeley.edu/geology/tecmech.html; Feb. 22, 2005) The main features of plate tectonics are: The Earth's surface is covered by a series of crustal plates. The ocean floors are continually, moving, spreading from the center, sinking at the edges, and being regenerated....
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Evolution overview 2010 - EVOLUTION OVERVIEW In talking...

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