Evolution (Introduction)

by dhw, Friday, July 24, 2009, 07:57 (5600 days ago) @ David Turell

The Theory of Evolution is not a single idea, and we've already seen on this forum that many misunderstandings arise because we don't always differentiate between its component parts. I therefore thought it might be useful to provide a summary of the salient points that are generally accepted or are in dispute. - 1) The Theory of Evolution does not deal with the origin of life.
2) The earliest forms of life are presumed to have been self-replicating molecules.
3) These molecules were able to undergo change and to reproduce the changes.
4) Changes can occur through random mutation, random combination, and the outside influence of the environment.
5) Beneficial changes survive through natural selection. - 1), 2) and 3) raise the problem of Chance v. Design. Do we or do we not believe that the complexities of the original mechanism could fashion themselves spontaneously? - 4) and 5) raise the question of whether new species evolve step by step (phyletic gradualism) or come into being suddenly (punctuated equilibrium). This is also an issue with regard to complex new organs and systems (e.g. the change from asexual to sexual reproduction), and provides further material for the Chance v. Design debate. - It is possible to accept some individual components of the theory while questioning others. - The theory is compatible with Theism but not with Creationism. - One further discussion point is whether evolution is or is not purposeful (teleology). - This summary is simply an attempt to clarify the lines of argument, but please feel free to correct and/or supplement it.