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Adolf Hitler's name is spelt differently in the same paragraph. (Adolph and Adolf) The correct spelling is Adolf. <small>-- The preceeding unsigned comment was added by [[User:Luojie|Luojie]]
Adolf Hitler's name is spelt differently in the same paragraph. (Adolph and Adolf) The correct spelling is Adolf. <small>-- The preceeding unsigned comment was added by [[User:Luojie|Luojie]]
== Evolution ==
A first stab at proposed changes to the [[theory of evolution]] page.
The '''theory of evolution''' is a term primarily used to describe two different concepts:
* The idea that organisms change over many generations through the process of [[variation]] and [[natural selection]]
* The idea that all life on Earth is descended from a single protocell, and differentiated into its various forms solely through the processes of random variation and natural selection.
While there is no controversy regarding the truth of the theory of evolution in the first sense, there is a great deal of public controversy regarding its truth in the second sense. Specifically, [[creationism]] is an alternate viewpoint which holds that all life is ''not'' related, and life did ''not'' develop entirely by the processes of variation and natural selection; rather, a Creator designed and created life in a number of ''different'', ''distinct'', and ''unrelated'' forms, and endowed that life with the capacity to adapt to a changing environment through the processes of variation and natural selection.
== Mechanisms of evolution ==
The following mechanisms are proposed for the processes of evolution:
=== Origin of life ===
* [[Metabolism world hypothesis]]: the hypothesis that life originated with a spontaneous non-genetic metabolica cycle, and later evolved into cells;
* [[RNA world hypothesis]]: the hypothesis that life originated with RNA, which had the capacity to act both as gene and enzyme;
=== Variation ===
* [[Random mutation]]: random changes in the genetic code;
* [[Recombination]]: targetted shifts in large sections of the genetic code, primarily through [[sexual reproduction]]
=== Selection ===
* [[Natural selection]]: the removal of less adapted lifeforms from the environment
* [[Genetic drift]]: the gradual elimination of genetic variation from a gene pool through [[stochiastic]] functions;
[[User:Ungtss|Ungtss]] 22:21, 24 June 2007 (EDT)