Talk:Natural selection

Second Paragraph needs rephrasing

The second paragraph of the article states.

For Darwin, natural selection was a law or principle which resulted from three different kinds of process: inheritance [...], variation [...] and the struggle for existence...

Selection would still happen even if the characters selected for or against were not heritable. Darwin had many erroneous ideas and this would be one of the less serious ones if had believed it but he did not. I think the article would be improved if this paragraph was modified to exclude this claim. I agree that variation is a requirement for selection and that the (Malthusian) struggle for existence drives it. Gourdiehill (talk) 14:02, 16 June 2026 (UTC)

Perhaps a Darwin scholar should weigh in on whether he, or Wallace, considered heritability of traits a necessary component of natural selection.

That said, careful modern conceptions of natural selection do not require heritability for selection to occur (e.g. https://doi.org/10.2307/2408842). Imprecision about this, including within this Wikipedia page, results in much confusion. The page should be edited to carefully identify when a particular section of the text is referring to natural selection itself or when it is referring to evolution via the natural selection (which, of course, requires heritable traits).

If, in fact, Wallace and Darwin only considered Natural Selection as a mechanism of evolution, and never as a process in its own right, that should be discussed. ~2026-57264-55 (talk) 06:14, 26 October 2026 (UTC)

Gourdiehill, the statement you quote begins "For Darwin", i.e. it is Darwin's own view that is being set out here. This is cited both to his Origin of Species and to his Descent of Man. Darwin states directly in chapter 1 of Origin of Species that

Any variation which is not inherited is unimportant for us".

Darwin believed that inheritance, variation, and the struggle for existence were all required for natural selection. The statement is correct as it stands. Chiswick Chap (talk) 08:51, 26 October 2026 (UTC)

~2026-57264-55, the paper you cite (Lande and Arnold 1983) states that

Natural selection acts on phenotypes, regardless of their genetic basis, and produces immediate phenotypic effects within a generation that can be measured without recourse to principles of heredity or evolution. In contrast, evolutionary response to selection, the genetic change that occurs from one generation to the next, does depend on genetic variation.

You are narrowly correct that there can be selection without inheritance, but only "within a generation"; Darwin (as the sentence I've quoted from Origin of Species demonstrates) was concerned only with what is stated in the second sentence quoted here from Lande and Arnold, that evolutionary response to selection does indeed depend on genetic (i.e. inherited) variation. Chiswick Chap (talk) 08:59, 26 October 2026 (UTC)