Evolution and Carbon Dating - Source 1 Taken from an...

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Source 1 – Taken from an article on evolution and its proof as can be seen in Wikipedia, a free online encyclopedia. The carbon 14 dating method, originally developed by Willard F. Libby and his team of scientists at the University of Chicago, Illinois, is a method of finding, fairly accurately (within 56,000 years), the dates of when certain tested living things were alive. Carbon dating is a variety of radioactive dating which is applicable only to matter which was once living and presumed to be in equilibrium with the atmosphere, taking in carbon dioxide from the air for photosynthesis. Cosmic ray protons blast nuclei in the upper atmosphere, producing neutrons which in turn bombard nitrogen, the major constituent of the atmosphere. This neutron bombardment produces the radioactive isotope carbon-14. The radioactive carbon-14 combines with oxygen to form carbon dioxide and is incorporated into the cycle of living things. The carbon-14 forms at a rate which appears to be constant, so that by measuring the radioactive emissions from once-living matter and comparing its activity with the equilibrium level of living things, a measurement of the time elapsed can be made. [Large part of the article omitted for it is to large to include in its entirety] Morphological evidence Fossils are important for estimating when various lineages developed. As fossilization is an uncommon occurrence, usually requiring hard parts (like bone) and death near a site where sediments are being deposited, the fossil record only provides sparse and intermittent information about the evolution of life. Fossil evidence of early life is sparse before the evolution of organisms with hard body parts, such as shell, bone, and teeth, but exists in the form of ancient microfossils and the fossilization of ancient burrows and a few soft-bodied organisms. Nevertheless, fossil evidence of prehistoric organisms has been found all over the Earth.
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This note was uploaded on 10/26/2008 for the course ARTSGEN 1005 taught by Professor Mannigan during the Winter '05 term at The Art Institute of Pittsburgh.

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Evolution and Carbon Dating - Source 1 Taken from an...

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