Date: Thu, 23 May 1996 10:30:57 -0500 (EST)
Subject: Dr. Blood Strikes Again


     I have not yet dug through my mail, but I wish to
correct a silly argument that I made yesterday in response
to a question raised by Jerry Levy.  That all pure-blooded
Indians in South America are 0 blood type does not suggest
that if A were the original blood type, humanity must have
originated in South America.  
     Before going further let me note that Jerry's question 
did not alter my main original point:  that there are mutations
of little selective/adaptive significance whose distribution/
spread is essentially a random process of migration, etc., thus
suggesting a limit to extreme adaptationism, without denying 
that their are selective adaptive processes going on in evolution.
     As regards blood types, although we do not know for certain,
there are strong reasons for believing that O was the original
type, A was a followup mutation, although quite far back in 
human evolutionary history, and that B is a relatively recent
mutation, probably occurring less than 10,000 years ago.
     O is by far the most common blood typy gene there is.  Globally
about 50% are O blood type, 40% are A, 10% are B, and about 3% are
AB.  But O is recessive meaning those 50% are OO.  Among the A's
are lots of AO's and among the B's are lots of BO's (pew).  Thus
in terms of the genes themselves it is probably 75% globally 0,
20% A and about 5% B.
     But more significant than that is the fact there O is virtually 
universally distributed.  There is no known human subpopulation above
the family level that is without O blood type, indeed 15% seems to
be about the minimum anywhere and that is people who are OO, thus
suggesting more than 30% of the actual genes being O.  But there are
lots of people with no A, e.g. pure-blood South American Indians.
But nobody knows when or where the A gene originated, is distribution
being rather peculiar.  
     B was since 10,000 years ago given its
strongly Eurasian base.  Eskimos exist on both sides of the Bering
Strait (known as "Chukchis" in Russia) and were the last Native 
Americans to arrive, definitely quite recently.  They are the only 
Native American group among whom B is found among pure bloods.  Also
no B among the Basques who have more successfully resisted invasions
and intermarriages than any other European group (even the Gaelic
speakers have some Central Eurasian input, given that Gaelic is an
Indo-European language, but Basque is not).  The migration distribution
of B is actually historically traceable from its likely Central Asian 
origin
Barkley "Dr. Blood" Rosser 


     --- from list marxism2-AT-lists.village.virginia.edu ---