Discuss the process of natural selection as defined by Darwin. How did Darwin?s theories differ from his prede?

Simply put, Darwin described natural selection as the preservation of particular [heritable] traits that are more useful than others in order to maximize survival and reproducibility.  For instance a particular trait within a population of organisms may cause certain ones to "out perform" their competition for resources.  Slowly overtime the organisms that held that trait will continue to out perform their competition and the competition with the less efficient "version" of that trait will be more susceptible to death.  As the weaker competitors die off, the alleles coding for that trait will slowly be lost within the population because of the lack of reproduction in the less efficient organisms. The poor alleles are gone for good and the better trait will eventually be expressed within the whole population.  His theories have more than been "proven" to be correct.  There have been many studies as well as discoveries over the past few decades that very much support his theory.  It's funny, there is more than a sufficient amount of proof to determine the legitimacy of his studies yet, there is no proof, studies, other theories, or any other discoveries of any kind that you could legitimately say disprove the theory of evolution.  The phylogenic tree has been traced so far back with tremendous accuracy that anyone who has been presented and understood with the facts presented by a knowledgable evolutionist can not deny its credibility.