Side Comments on Kondrashov’s Paradox

[Tim]

In his latest post, Zach has said a couple of things that gelled with things that I’ve said/thought previously:

@talkpopgen

Paul seems to be arguing that when Sanford uses the word universal or never, so long as he uses different verbiage later on, then he has not in fact defined GE in such strong terms. The fact that you can find instances in which Sanford clearly does not mean that GE is universal or that un-selectable always means un-selectable doesn’t mean that I quote-mined him – it means that he contradicted himself. He could have said generally or rarely. Words have meaning.

This lack of precision is what I was alluding to when I said:

@Tim

2. The empirical evidence against it, and GE-proponents ad hoc hand waving to dismiss that evidence – giving the appearance that GE is unfalsifiable, and thus unscientific.
3. The fact that (2) suggests that GE lacks the rigor and precision to be considered a serious hypoothesis, rather than one that is ‘not even wrong’.

I cannot help but suspect that GE, at least as Sanford describes it in his book, contains enough contradiction, equivocation and/or ambiguity such that any counterexample against it can be dismissed as being excluded by some version or interpretation of it.

@talkpopgen

If we’re more generous, then “unselectable” is at best misleading. Consider the case in which Ns = 0.5 (beneficial, near neutral) and Ns = -0.5 (deleterious, near neutral). The former is 7.38 times more likely to fix than the latter, and 2.31 times more likely to fix than a strictly neutral mutation. This seems nothing like “unselectable”, in any sense of the word.

This highlights a problem I have had with GE since I first encountered Sanford’s “No Selection Zone” chart. This is not a region where selection disappears completely (but rather where drift dominates over selection), a non-discontinuous effect (there will only be slight differences slightly inside versus slightly outside this zone), and you will have opposite interaction on either side of the y-axis – with drift diminishing selection on one side, but reinforcing it on the other. These concerns seemed intuitively logical to me, but it is good to see numbers confirming that intuition.

This in turn highlights something I have noticed repeatedly over my interaction with PS. Whilst there are many issues with creationist claims that need a deep knowledge of the relevant science to adjudicate, there is with, considerable regularity, issues that are obvious even to a reasonably well-read layman such as myself.

This means that, although I cannot enumerate all the flaws with creationism, I can see for myself, and without ‘taking the word’ of others, enough flaws that creationism does not hold together.