https://gregladen.com/blog/2008/02/05/the-three-necessary-and-suffic-1/ Wed, 06 Feb 2008 07:54:47 +0000 hourly 1 https://wordpress.org/?v=6.4.6 https://gregladen.com/blog/2008/02/05/the-three-necessary-and-suffic-1/#comment-3568 Wed, 06 Feb 2008 07:54:47 +0000 http://scienceblogs.com/gregladen/2008/02/05/the-three-necessary-and-suffic-1/#comment-3568 Thank you so much for stating that sexual selection is just a subset of natural selection. This always seemed obvious to me and yet it’s so frequently treated as a distinct and separate “force” (I think physicists may object to this use of the word – in fact I think physicists may object to you calling gravity a force, too 😛 – I have usually heard NS, genetic drift etc referred to as the mechanisms of evolution rather than forces). I never really understood why; as long as you understand that adaptation isn’t about survival but about FITNESS … well. I’ll stop ranting. 😉

]]> https://gregladen.com/blog/2008/02/05/the-three-necessary-and-suffic-1/#comment-3567 Tue, 05 Feb 2008 17:37:50 +0000 http://scienceblogs.com/gregladen/2008/02/05/the-three-necessary-and-suffic-1/#comment-3567 Bob: I think my point here is similar to yours. The ordering is a pedagogical tool, not a functional description of the process. Stephen and bob: Exactly.

]]> https://gregladen.com/blog/2008/02/05/the-three-necessary-and-suffic-1/#comment-3566 Tue, 05 Feb 2008 14:27:43 +0000 http://scienceblogs.com/gregladen/2008/02/05/the-three-necessary-and-suffic-1/#comment-3566 As an aside, since you want to subsume what is usually called ‘artificial selection’ under your definition, why not drop the ‘natural’ and just say you’re stating the necessary and sufficient conditions for a selection process?

]]> https://gregladen.com/blog/2008/02/05/the-three-necessary-and-suffic-1/#comment-3565 Tue, 05 Feb 2008 14:15:29 +0000 http://scienceblogs.com/gregladen/2008/02/05/the-three-necessary-and-suffic-1/#comment-3565 Good definition. I think it’s worth pointing out that “biological system” is not one of the three requirements. To my mind, one of the coolest things about natural selection is that it applies universally; if those three conditions are satisfied, there’s no way you can stop something from evolving, be it a biological species, a language, a computer program, or whatever.

]]> https://gregladen.com/blog/2008/02/05/the-three-necessary-and-suffic-1/#comment-3564 Tue, 05 Feb 2008 12:48:00 +0000 http://scienceblogs.com/gregladen/2008/02/05/the-three-necessary-and-suffic-1/#comment-3564 No objections, except for the bit about the “ordering” of the three conditions being important. All three must be present, period. Ordering is simply an artifact of exposition (i.e., not being able to say three distinct things at once).

]]> https://gregladen.com/blog/2008/02/05/the-three-necessary-and-suffic-1/#comment-3563 Tue, 05 Feb 2008 12:35:13 +0000 http://scienceblogs.com/gregladen/2008/02/05/the-three-necessary-and-suffic-1/#comment-3563 Extremely well put.

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