Evolution!? - (Mar/14/2006 )

Hi all..

Can u plz (detail-ly) define "Evolution" for me..
(plz include the aim of evolution in it, and the process of it -if any- is it directed by/towards something?)

I asked also coz i wanna know if there were "a so-called perfectly fit" specie on the universe.. would it stop evolving? (there's nothing stopping it from undergoing mutation, right? but would this mutation lead to evolution?)

Plz clear my doubts:)

Thanks!

1 the process by which different kinds of living organisms are thought to have developed and diversified from earlier forms during the history of the earth. The idea of organic evolution was proposed by some ancient Greek thinkers but was long rejected in Europe as contrary to the literal interpretation of the Bible. Lamarck proposed a theory that organisms became transformed by their efforts to respond to the demands of their environment, but he was unable to explain a mechanism for this. Lyell demonstrated that geological deposits were the cumulative product of slow processes over vast ages. This helped Darwin toward a theory of gradual evolution over a long period by the natural selection of those varieties of an organism slightly better adapted to the environment and hence more likely to produce descendants. Combined with the later discoveries of the cellular and molecular basis of genetics, Darwin's theory of evolution has, with some modification, become the dominant unifying concept of modern biology.

2 the gradual development of something, esp. from a simple to a more complex form : the forms of written languages undergo constant evolution.

3 Chemistry the giving off of a gaseous product, or of heat.

4 a pattern of movements or maneuvers : silk ribbons waving in fanciful evolutions. 5 dated Mathematics the extraction of a root from a given quantity.

If I may:

"Differential success between imperfect replicators" is hard to beat for conciseness.

Fitness is always defined by current, local conditions. No, there's no such thing as a "perfectly fit" organism; rather, we see organisms driven by selection toward "peaks" in local fitness landscapes. Large populations do tend to stabilize at such peaks when environmental conditions as a whole are stable. Whether small variations due to further random mutation constitute "evolution" might be debated. If debating that sort of thing is your bag (or if you just have more doubts, questions, whatever) some very high-calibre discussions can be found at EVC forums.