Natural selection

Natural selection is the mechanism of evolution proposed by Charles Darwin, and is now generally accepted by the scientific community as the best explanation. The idea is that certain traits inherited by living things from their parents are preserved due to the selective advantage they provide to their holder, allowing the individual to leave more offspring than individuals without the trait(s).

Natural selection can be expressed as the following general algorithm:

1. IF there are variations between entities, and
2. IF these variations are heritable, and
3. IF one variant is more successful at a given task, and
4. IF that relative success allows more copies of the entity to be passed on to the next generation,
5. THEN selection will produce change over time (Evolution!)

Note that the above algorithm is made with no explicit reference to biological entities. Thus, a form of natural selection could occur in the non-biological realm. Note also that this formulation does not rule out selection occurring at all biological levels (e.g. gene, organism, group). Nor does it matter what the cause of variation is: some creationists, for example, generally accept that evolution occurs, but posit that God causes the changes that lead to it.

Darwin first outlined his theory in two unpublished manuscripts written in 1842 and 1844 and more fully developed it for publication in The Origin of Species, especially Chapter 4.

See also; [artifical selection]?, sexual selection, evolution