Talk:Evolution of cells

Article Checklist for "Evolution of cells"

Workgroup category or categories	Biology Workgroup [Categories OK]
Article status	Developed article: complete or nearly so
Underlinked article?	No
Basic cleanup done?	Yes
Checklist last edited by	luke 00:26, 20 March 2007 (CDT)

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Life

An early question that needs to be confronted, indeed a question that in the last analysis requires definition, is: What is life? Most biologists would agree that self-replication, genetic continuity, is a fundamental trait of the life process. Systems that generally would be deemed nonbiological can exhibit a sort of self-replication, however. Examples would be the growth of a crystal lattice or a propagating clay structure. Crystals and clays propagate, unquestionably, but life they are not. There is no locus of genetic continuity, no organism. Such systems do not evolve, do not change in genetic ways to meet new challenges. Consequently, the definition of life should include the capacity for evolution as well as self-replication. Indeed, the mechanism of evolution---natural selection---is a consequence of the necessarily competing drives for self-replication that are manifest in all organisms. The definition based on those processes, then, would be that life is any self-replicating, evolving system (Norman R Pace 2001).

really wonderful. Nancy Sculerati MD 01:49, 5 February 2007 (CST)