From: agha@cs.uiuc.edu (Gul Agha)
Subject: Re: A query
Organization: University of Illinois, Dept. of Comp. Sci., Urbana, IL
Distribution: worldwide
Date: Tue, 15 Dec 1992 18:30:16 GMT


   From: v999r9ne@ubvmsd.cc.buffalo.edu (Vikram S Sinha)
   Newsgroups: soc.culture.pakistan

   I have travelled to pakistan on numerous occasions with friends and 
   family.I noticed a strange trait amongst the pakistani people. I have
   observed that first cousins marry each other in most cases

Sinha sahab!

I don't know about most, but it is common among some families and
clans.

   Biologically this is nothing short of second order incest.  

Biologically, we are all guilty of nth order incest.  What order is
your pleasure -- 30th order or so may put you out of reach of mating
with other apes?

   It is
   proven that inbreeding (even amongst first cousins) leads to the genetic
   mutation of the offspring eventually. 

Well, let's get some biology straight.  Mutations are an independent
random process which has nothing known to do with incest or other
combinatory factors.  Inbreeding increases the probability of lethal
deleterious recessive genes appearing in pairs -- many of us carry a
number of such genes because they are manifested rarely in the
phenotype and perhaps because they provide other genetic advantage.

With incest, the probability of having the same pairs of genes is 0.5.
With first cousins (assuming no other cross factors such as closely
related aunts and uncles), the probability is 0.125.  The relatedness
can increase the probabilities slightly but it is an exponential
function of the biological distance.

Now, when infant mortality is as high as it is now, 

        0.125 x Prob. of deleterious gene

may not be a noticable factor.

Over many generations, this probability can increase, but only if the
gene pool is isolated -- not the case in Pakistani society.  However,
a serious problem in certain other groups, such as those practicing
exclusive mating.  For example, some South Indian Brahmins have
elaborate categorizations determining exclusive classes of potential
mates, or in other isolated populations such as Eskimos.  This may
have led to other cultural practices in geographically isolated areas,
as in some Eskimo tribes -- such as that captured in the proverbial
"hospitality" of sharing one's mate with a passing stranger.. there
being not many of the latter in the "olden" days..)

   I am sure islam does not condone this
   and I have met muslims from other countries too,they say that this practice
   is totally alien to them. 

Islam has nothing I know of to say about this.  It essentially
prohibits relations which are related by 0.25 biological relatedness
factor (and other adoptive equivalents).

   They like many others find this practice of 
   marrying ones paternal or maternal uncle's or aunt's offspring
   disgusting.

While I would not recommend first cousin marraiges, I would not use
offensive language for some other people's cultural practices.
(However, I can understand your frustration if you did just lose out
to some first cousin :)

   Would someone please enlighten me as to why this custom is prevelant in
   Pakistan.

Well read some cultural anthropology.  (Why did some ancient vedic
characters practice polyandry but only with brothers?).  

But in the end, who knows?

However, I would at least recommend postpone insulting others'
cultural practices until one is at least sophisticated enough not to
come across as ignorant and crass.  In other words, first get the
biology straight.  Then do it with some class or don't :)

Now some reading.. pick up Dawkins, "The Selfish Gene" and E.O.
Wilson, "On Human Nature" for some sociobiology.  Then move on to
cultural anthropology.. then come back and tell us about it.

Peace,

Gul Agha
Newsgroups: soc.culture.pakistan