Natural selection
Natural selection follows from three facts about a population: individuals vary, some of that variation is heritable, and more offspring are produced than can survive. The variants that leave more surviving offspring become more common in the next generation. Nothing chooses and nothing aims; the outcome is a statistical consequence of differential survival and reproduction, which is why Darwin also called it descent with modification.
Why it matters
It is the one mechanism that produces apparent design without a designer, and it is the reason biology can explain fit between organism and environment without appealing to purpose.
Also written: selection, selective pressure
Where it comes up
Read about Natural selection on Wikipedia
Sources
- Natural selection Wikipedia
- Natural Selection Stanford Encyclopedia of PhilosophySets out the argument formally and separates selection from the drift it is often confused with.
- Understanding Evolution UC Museum of Paleontology, BerkeleyA teaching site with worked examples; the best first stop if the abstract statement will not stick.
