In 2016 a Meta post discussed the problem of questions “that ask for why evolution did not lead to situation-X”. It was suggested that a community wiki question be created, and provided with an extensive range of answers. Then posters of such evolutionary questions could be referred to it and their questions closed as duplicates. This was done by @WYSIWYG, and attracted several good community answers, which, in my opinion, cover most of the bases. This is frequently used and is a valuable resource for the site.


One user (@terdon) suggested a title “If trait X would be advantageous to an organism, why hasn't it evolved?” but, in fact, the community question was given the broader title:

“Why do some bad traits evolve, and good ones don't?”

To my mind the main problem is that this is in fact two different questions which have quite different possible answers. This antagonizes many posters, especially as the less frequent concern (bad traits evolving) appears first in the title. Indeed it always annoyed me as, from the title alone, it seemed to me that the question was unlikely to be a duplicate. It was only this month when an answer came up on Meta that I actually looked at the community question and saw that it was different from my expectation and extremely useful.

A secondary problem I have is with that the wording of the title, which refers to “good traits”. In fact these are “traits that individuals believe would be advantageous and I think the title should be rephrased to reflect this. Indeed one of the answers specifically deals with this urge for posters to play God with evolution, pointing out that their beliefs of what would be advantageous may well be incorrect.


  1. That I split the community question into two questions by editing the existing one and creating a second.

  2. The edited question would be entitled:

Why has a trait that would appear to be advantageous not evolved?

  1. The new question would be entitled something like (suggestions for improvement solicited):

Why has a trait evolved that can have a deleterious effect on an organism or population?

Here one accepts that there are unequivocally deleterious effects, e.g. those resulting from haemoglobinopathies. Answers or part answers addressing this (fewer, but some good ones nevertheless) would be moved to the new question.

Anticipated objections to proposal

The main objection to this proposal that I anticipate is that there are a large number of instances of reference to the community question by its current title, and that it would be misleading if the links led to a question with a different title. I would volunteer to edit, but the references tend to be in close notices that are autogenerated and cannot be edited by normal users.

Why don’t I just go ahead and do it?

I could, but then someone might roll it back, and then I would want to argue the case and we would go to and fro… Better to discuss it first, so that people can consider before getting into a ping-pong game.

  • 2
    $\begingroup$ Thanks for posting it in meta first. It's a hotly debated post. In fact I've never been fond of closing down myriads of questions with apparent little overlap with the linked post, but I'll not start an old discussion. However, I do think that focusing the question by splitting it up may be a good to prevent future closures of questions based on the posts having arguable overlap with the linked question here. $\endgroup$
    – AliceD Mod
    Sep 12, 2022 at 11:33
  • 1
    $\begingroup$ I agree with the proposal. I think (?) that closed as duplicate messages will update themselves with the title change, as the closure refers to the unique post ID, not the title, which could change over time. For example, this question's post ID is 4318. It will always be 4318, even if I change the title to "Cheese is the best, amirite?" $\endgroup$
    – MattDMo
    Sep 21, 2022 at 22:22
  • $\begingroup$ Sorry I haven't got round to doing anything about this yet. My other commitments, like buses... Something for the long winter evenings. $\endgroup$
    – David
    Oct 17, 2022 at 13:57


You must log in to answer this question.

Browse other questions tagged .