Changes

{{rewrite|Its role in [[Evolution]] is expressed vaguely. How does natural selection "help" bring a new species into existence? Merely by weeding out the "mistakes"?}}

{{rewrite|Its role in [[Evolution]] is expressed vaguely. How does natural selection "help" bring a new species into existence? Merely by weeding out the "mistakes"?}}

'''Natural selection''' is a principle that was proposed by [[Charles Darwin]] and Alfred Russel Wallace, who noted that organisms which were better adapted to their environment tended to survive longer and reproduce more than less well-adapted organisms.  

The fundamental statement of '''natural selection''' is that heritable traits which are beneficial will become more numerous in successive generations, while heritable traits which are harmful will become more scarce.  This principle is general, and applies to any system of individuals which reproduce; it is most commonly applied to systems of living organisms. 

 

 

Natural selection is a principle that was proposed by [[Charles Darwin]] and Alfred Russel Wallace, who noted that organisms which were better adapted to their environment tended to survive longer and reproduce more than less well-adapted organisms.

These organisms have to be able to survive long enough to reproduce, and produce viable offspring capable of the same, in order to ensure the continuing survival of their genetic traits.  They do not have to be perfectly adapted to their environment; they only have to be able to survive in it.

These organisms have to be able to survive long enough to reproduce, and produce viable offspring capable of the same, in order to ensure the continuing survival of their genetic traits.  They do not have to be perfectly adapted to their environment; they only have to be able to survive in it.

Natural selection is not [[mutation]]. It does not make anything new, alter anything, etc.  Natural selection can cause extinction based on survival of the fittest, but the processes of creation and mutation lie outside the scope of natural selection.  

Natural selection is not [[mutation]]. It does not make anything new, alter anything, etc.  Natural selection can cause extinction based on survival of the fittest, but the processes of creation and mutation lie outside the scope of natural selection.  

==Generality==

==General Requirements==

 

While it is commonly applied to competition between living organisms, natural selection is far more general mathematical model.  In general, natural selection applies to any system where a group of different "individuals" (where an "individual" could be anything from a bacterium to a computer program to an architectural design) is evaluated by some metric; each individual is then either discarded or duplicated based on the results of the evaluation (usually with some stochastic weighting of the probabilities of discarding/duplication).  The process is then repeated.  In most examples, the metric of evaluation is relative--that is, an individual only scores "well" if its score is high compared to the rest of the group.

In any such system, individuals whose traits allow them to reproduce more effectively will soon come to dominate the population.  

== Variation and Randomness ==

== Variation and Randomness ==