IUBio

Homosexual behavior in primates

Ram Samudrala ram at mbisgi.umd.edu
Tue Oct 31 21:05:34 EST 1995


This is crossposted to bionet.molbio.evolution since I don't get sci.bio.

Gene Ward Smith (gwsmith at cats.ucsc.edu) wrote:

>As I keep finding occasion to mention, perhaps the most interesting
>example is the bonobo, _Pan paniscus_.

I will have to look into this.  What you say is indeed interesting.

>This is one reason why the suggestion that the genetic roots of
>homosexual behavior come as the result of mutation is probably
>wrong. Since, it appears, it is a part of our genetic heritage as a
>primate, why suppose that it is *now* suddenly anti-adaptive and,
>moreover, a mutation?

Oh, I think if it can be conclusively shown that the homosexual
behaviour in the bonobo is genetic, it would be hard to say it is
anti-adaptive, or even a mutation.  I think if it can be shown to be
genetic in humans, then I don't believe it's a mutation or an
aberration.  

>>I don't think homosexuality is genetic (even given Dean Hamer's
>>results in this regard).  I think sexuality is a choice (both hetero
>>and homo), although it might be an unconscious one .  I think whatever
>>floats your boat is the way to be.

>What I think or you think does not matter. What the evidence suggests
>is what is important. 

Exactly.  But I say this keeping the available evidence in mind.  If
you recall Dean Hamer's results in this regard, he was able to find
similar genetic markers in 33 out of 40 pairs of homosexual brothers.
Now, even this doesn't explain all of homosexuality, or even male
homosexuality.   But even explaining a certain kind of homosexuality
(in the 33 brothers) would be a good result.

I remain skeptical, however.  Has there been an indenpendent
replication of his results?  

>Moreover, what sense does it make to say something is an "unconscious
>choice"? 

It's simply differentiating between nature and nurture.  Like an
inherited and non-inherited version of a certain disease (perhaps this
is a bad example), say.   I said unconscious mainly because the
standard argument to my comment "I don't recall making a comment".
However, I am simply interested in knowing whether it is nature or
nurture. 

>Is this a falsifiable hypothesis?

It is, if you understand the nature of human sexual development.

>Is it a hypothesis at all--that is, can you explain what that means?

The question is, is human sexuality pre-determined, or is it a result
of the environment.  For example, the colour of your eyes is
pre-determined the moment you're conceived.  Is this the case for
sexuality?  

My belief, however, is that sexuality is a complex process involving
many genes and that it is evolutionarily disadvantageous to have it
pre-determined.  And since we really don't have proof either way (and
as far as I know, the only convincing genetic (non-statistical) study
has been Hamer's)... I think this is as good as any other theory out
there. 

--Ram

me at ram.org  ||  http://www.ram.org  ||  http://www.twisted-helices.com/th
  Tell me why I have to be a powerslave?
  I don't want to die I'm a god why can't I live on?  
  When the life giver dies all around is laid waste.  
  And In my last hour I'm a slave to the power of death.   ---Iron Maiden



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