joe{at}removethispart.gs.washington.edu wrote 


> > It seems there are two types of gambler's fallacy, as described 
> > on the following webpage:
> > 
> > http://www.nizkor.org/features/fallacies/gamblers-fallacy.html
> > 
> > I think the one associated with genetic drift is the second of 
> > the two on this page. 
> 
> Those are pages on mistakes you can make calculating probabilities.

The text I referred to has nothing whatsoever to do with, "mistakes
you can make calculating probabilities."  If you think I'm wrong on
this then we can only wonder why, after all this time, you haven't
pointed out the exact text that indicates otherwise (don't be shy
about quoting it directly).

> They are not about whether anything "is causal".

Yes, they are.  (This is all it's about.)

> > So I have asked McGinn:
> 
> > So where is there, in the calculations, an invalid assumption of
> > independence that makes the calculations incorrect enough to worry
> > about?
> 
> The answer seems to be that he never asserted that.

Right.  (I would think by now you would have figured this out.)

> That the discussion
> was always about whether genetic drift "is causal".  Can't imagine how
> I made that mistake -- thinking that an assertion that a fallacy is being
> committed means that one is asserting that the calculations are fallacious!
> ;-)

I can't imagine how you made that mistake either.  (But then I don't
have direct access to your imagination.)

> 
> McGinn also posted lots of places where I said genetic drift causes
> changes in gene frequency.  I said those, and will again.  It is
> useful to say that.

I was only commenting on the lack of accuracy of these comments.

> But asking about ultimate causation here is useless,

(I suspect you are employing Mayr's notion of, "Ultimate cause,"
here.)  Why do you assume/conclude that asking about its ultimate
cause is useless?

> which I why I have not entered the discussion about whether genetic drift
> "is causal".  Considering it as an evolutionary force is useful and
> necessary. 

Why is it necessary to consider genetic drift an evolutionary force
if, in actuality, it isn't?

> Saying it brings about changes in gene frequencies is useful
> and necessary.

I would suggest that the lack of one to one correspondence between
temporal fluctuations in a populations genes and chaotic causation in
the environment indicates that it's usefulness is to obscure the fact
that this one to one correspondence doesn't actually exist.  If this
is the kind of usefulness you are talking about, I agree, it's useful
to that end.

> 
> McGinn has argued elsewhere that I withdrew from the discussion of
> causativeness of genetic drift when I had no answer to his charge that
> genetic drift commits the Gambler's Fallacy by assuming independence
> of nonindependent events.

Right.  I suspect (I don't know) that you realized the lack of one to
one correspondence and bailed.

> Nope, I never understood his charge well enough to
> be crushed by it.  

Okay.  I was just giving your intellect the benefit of the doubt.

> I still don't know why it's OK to use the genetic
> drift calculations to predict the changes of gene frequency,
> but somehow not OK to think of genetic drift as causing those changes. 

In this passage you are revealing the circularity of your
understanding of genetic drift: you assumed genetic drift is causal.

> Or why it's important to not think of it as causing those changes.

Because it is not a thing, and only a thing can be causal.

> 
> Final comment: I get a hint in one of his many posts on this stuff that
> McGinn thinks that in using the concept of genetic drift we are somehow
> assuming that natural selection is not occurring too.

No.  I think that in using the concept of genetic drift you are
somehow assuming that Genetic Drift is a force different/distinct from
NS when it's not.

Jim
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