On Sep 7, 11:55 pm, Tak To <ta...@alum.mit.eduxx> wrote:
> On 9/7/2012 11:00 AM, Peter Brooks wrote:
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> > On Sep 7, 4:24 pm, Tak To <ta...@alum.mit.eduxx> wrote:
> >> On 9/7/2012 3:56 AM, Peter Brooks wrote:
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> >>> On Sep 7, 8:40 am, Tak To <ta...@alum.mit.eduxx> wrote:
> >>>> On 9/7/2012 1:21 AM, Peter Brooks wrote:
>
> >>>> Just want to make sure: plenty of evidence of which
> >>>> of the following?
>
> >>>> (1) most homosexual chaps also find naked women
> >>>> exciting;
> >>>> or
> >>>> (2) there being a continuum between chaps who are
> >>>> allergic to men on the one end and chaps who
> >>>> allergic to women on the other
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> >>> Both.
>
> >> Any online references?
>
> >>> A sociobiological argument for the evolutionary survival of
> >>> homosexuality is that homosexuals do, indeed, reproduce (if they
> >>> didn't then you'd expect any heritable component to die out in a few
> >>> generations, unless carrying, but not expressing, the genes for
> >>> homosexuality carries some advantage). The argument, for male
> >>> homosexuality (I've not seen much discussion of the evolutionary
> >>> benefit of female homosexuality) is that, by appearing not to be a
> >>> sexual threat, homosexual men reduce male jealousy and female
> >>> circumspection in a way that enables them to get on sufficiently
> >>> intimate terms with women to inseminate them.
>
> >> It is just an argument. The ontological argument
> >> for the existence of god is another argument.
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> >>> Not all homosexuality is heritable, of course,
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> >> If at all.
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> > There's quite a good discussion of it all here:
> >
http://en.wikipedia.org/wiki/Biology_and_sexual_orientation
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> >>> and not all that is heritable is genetic.
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> >> Yes, but what you described below is not a
> >> mechanism of inheritance by any sense of the
> >> word.
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> > and?
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> >>> Both left-handedness and homosexuality can have
> >>> similar aetiology - an excess of testosterone during gestation, or, in
> >>> some cases, brain damage during birth. This is not to say (of course,
> >>> but enough people misunderstand for a caveat to be necessary) that,
> >>> despite both homosexuals and left-handers being more prevalent in
> >>> theatrics, they are the same, left-handers are not much more likely to
> >>> be homosexual, nor are homosexuals that much more likely to be left-
> >>> handed.
>
> >> Can have similar etiology, and can have disparate
> >> etiology.
>
> > That's a quaint spelling of it - I'd think it was the study of 'ands'
> > if it weren't for this context. I see that another quaint version is
> > 'aitiology'.
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> > If I hadn't meant that I wouldn't have said 'can', would I?
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> And?
>
I'm puzzled as to what you thought your comment added.
>
> >>> The differential aetiology leads to the continuum (using the term
> >>> loosely).
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> >> How?
>
> > See the above article, but anything that has such differential
> > aetiology will not be binary.
>
> It all depends on how the trait is defined. (By
> "differential etiology" I assume you meant "multi-
> factorial etiology", rather than the usual meaning
> of "differential diagnosis".) For example,
> the trait defined as X-and-Y (where X and Y are
> binary traits with different etiology) can be
> defined as binary: either X-and-Y or not-(X-and-Y).
>
Yes, multifactorial. If X and Y have different aetiology, then you
have the cases:
X + Y | ~X + Y | X + ~Y | ~X + ~Y
That is, from two binary traits, you get 4 possible outcomes. When you
have multiple binary traits, you get more. Thus, with something like
left-handedness or homosexuality, that's based on quite a few traits,
not all of them binary, you end up with many possible outcomes - what
I called a loose continuum.
>
> > It's a matter of simple observation that
> > some people are very strongly left-handed, some are ambidextrous and
> > most lie somewhere in between perhaps kicking and fishing sinistrally,
> > but doing everything else dextrally. The Kerrs are an unusual case of
> > strongly heritable left-handedness.
>
> This does not explain "how".
>
It wasn't supposed to, but what 'how' are you wanting explained? If
you look at the wikipaedia article that I posted, you'll see most of
what I've mentioned discussed, quite well and simply.