Changes

Skeptics of some aspects of evolutionary theory sometimes claim that '''evolution is an unproved theory'''.  It is true that the [[hypothesis]] that each species of life in existence now evolved naturally from a common annecestor, like any other scientific hypothesis, cannot be definitively proved.  However, that hypothesis and the hypothesis that all life on earth descends from one common ancestor is corroborated by molecular <ref>Brown, J. R. and W. F. Doolittle. 1995. Root of the universal tree of life based on ancient aminoacyl-tRNA synthetase gene duplications. Proceedings of the National Academy of Sciences of the United States of America 92:2441-2445.</ref><ref>Caetano-Anolles, G. 2002. Evolved RNA secondary structure and the rooting of the universal tree of life. Journal of Molecular Evolution 54: 333-345.</ref><ref>Gribaldo, S. and P. Cammarano. 1998. The root of the universal tree of life inferred from anciently duplicated genes encoding components of the protein-targeting machinery. Journal of Molecular Evolution 47:508-516.</ref> fossil <ref>Carroll, R. L. (1997) Patterns and Processes of Vertebrate Evolution. Cambridge: Cambridge University Press.</ref><ref>Sereno, P. C. (1999) "The Evolution of Dinosaurs." Science 284: 2137-2147</ref> geographical <ref>MacFadden, B. J. (1992) Fossil Horses: Systematics, Paleobiology, and Evolution of the Family Equidae. New York, Cambridge University Press.</ref> and morphological <ref>Darwin, Charles (1859), On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life, London: John Murray 1st edition.</ref> evidence.  Skeptics sometimes make the argument that evolution is ''just a theory'' or an ''unproved theory''.  For example, Pope Benedict XVI recently published ''Creation and Evolution'', in which he writes "<nowiki>[It]</nowiki> is also true that the theory of evolution is not a complete, scientifically proven theory."<ref>Creation and Evolution, Pope Benedict XVI, 2007, Sankt Ulrich Publishing.</ref> However, since all scientific knowledge can be defined as theory, this argument does not grasp the way in which scientific knowledge is accumulated. One could say for example, "since the cell theory is just a theory, it has not been proven that organisms are composed of cells."  

Skeptics of some aspects of evolutionary theory sometimes claim that '''evolution is an unproven theory'''.  It is true that the [[hypothesis]] that each species of life in existence now evolved naturally from a common annecestor, like any other scientific hypothesis, cannot be definitively proved.  However, that hypothesis and the hypothesis that all life on earth descends from one common ancestor is corroborated by molecular <ref>Brown, J. R. and W. F. Doolittle. 1995. Root of the universal tree of life based on ancient aminoacyl-tRNA synthetase gene duplications. Proceedings of the National Academy of Sciences of the United States of America 92:2441-2445.</ref><ref>Caetano-Anolles, G. 2002. Evolved RNA secondary structure and the rooting of the universal tree of life. Journal of Molecular Evolution 54: 333-345.</ref><ref>Gribaldo, S. and P. Cammarano. 1998. The root of the universal tree of life inferred from anciently duplicated genes encoding components of the protein-targeting machinery. Journal of Molecular Evolution 47:508-516.</ref> fossil <ref>Carroll, R. L. (1997) Patterns and Processes of Vertebrate Evolution. Cambridge: Cambridge University Press.</ref><ref>Sereno, P. C. (1999) "The Evolution of Dinosaurs." Science 284: 2137-2147</ref> geographical <ref>MacFadden, B. J. (1992) Fossil Horses: Systematics, Paleobiology, and Evolution of the Family Equidae. New York, Cambridge University Press.</ref> and morphological <ref>Darwin, Charles (1859), On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life, London: John Murray 1st edition.</ref> evidence.  Skeptics sometimes make the argument that evolution is ''just a theory'' or an ''unproved theory''.  For example, Pope Benedict XVI recently published ''Creation and Evolution'', in which he writes "<nowiki>[It]</nowiki> is also true that the theory of evolution is not a complete, scientifically proven theory."<ref>Creation and Evolution, Pope Benedict XVI, 2007, Sankt Ulrich Publishing.</ref> However, since all scientific knowledge can be defined as theory, this argument does not grasp the way in which scientific knowledge is accumulated. One could say for example, "since the cell theory is just a theory, it has not been proven that organisms are composed of cells."  

== Falsifiability Criteria  ==

== Falsifiability Criteria  ==