From: suter@VAX.MPIZ-KOELN.MPG.dbp.de
Newsgroups: bionet.molbio.hiv
Subject: origin and future of HIV
Date: 11 Dec 92 14:01:54 GMT
Distribution: bionet
Content-Identifier: 12
Original-To: hiv-biol@uk.ac.daresbury
Conversion: Prohibited

Subj:	Re: biology of HIV/AIDS
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+I'm not a virologist or parasitologist, but ...+
+
+In article <1992Dec6.155533.2523@infodev.cam.ac.uk>,
+mh10006@cl.cam.ac.uk (Mark Humphrys) writes:
+|> I wonder if anyone could answer some questions
+|> that have intrigued me about AIDS:
+|>
+|> 1.How common is it that a virus (or any parasite) 'succeeds'
+|>   in causing the extinction of a host species?
+|>   ( and thereby possibly causing its *own* extinction as a species )
+|>   Is this rare?
+|>   Could HIV destroy us, or will we always exist in an uneasy state
+together?
+|>   Is an equilibrium *always* reached?

+I suppose it's possible that even the dinosaurs were subject to
+viruses and other parasitic organisms, which may have contributed
+to their extinction.  Nature abounds with 'destructive' relationships,
+particularly among insects; spiders and mantises eat their mates,
+and some wasps will paralyze a 'host' and lay her eggs, and the
+larva feed on the still-living host.  There may be indeed be
+examples of parasite caused extinction (don't forget plants!), but
+if no humans were observing the species, how would anyone know?
+
+|> 2.Re:origins of AIDS -
+|>   If HIV/AIDS has only arisen in the last few decades in humans,
+|>   then surely it must be related to something humans have caused?
+|>   What I mean is that wouldn't it be too coincidental for a killer
+virus
+|>   to evolve now, of all times, after all these millions of years,
+|>   and wipe us out just a few geological-seconds after we become
+civilized?
+|>   Surely the origin of AIDS must be somehow related to the industrial
+society
+|>   which has only recently developed? ( e.g.pollution, environmental
+change )
+|>   Or do researchers simply consider it 'bad luck' that HIV happened
+to evolve now
+|>   instead of in a million years' time?
+
+You could also invoke alien (off-planet) intervention here, as well.
+
+The virus could also be much older, but fairly isolated until the
+last few decades.  Parasites evolve to take advantage of the hosts
+that are available; unfortunately for humans, HIV seems to prefer
+white blood cells, which has the side-effect of compromising our
+immune systems.

from sequence comparison between different HIV isolates, it was calculated
that the pre-HIV virus was formed between 40 and 150 yrs ago (i dont have
the reference for this, and perhaps there is already a better calculation 
available, this is also supported by the finding of HIV antigens in 
old blood conserves or human remains (record is about 40 yrs?)). its 
country of origin is supposed to be in africa, 
and as far as i know the virus is endemic there... like SIV.

perhaps the changing lifestyle of humans in general (we tend to travel more ?) 
has given the virus a chance to infect more and more of us... alltho these
theories are very unscientific (how can you falsify this ?) and useless 
(we can't stop our behaviour and its too late anyway). on the other
hand, evolution did not stop when modern man was born, and i can predict
with some self-confidence that some ugly new "parasites" will be formed 
in the next few hundred years. whether or not they will be man's downfall
is in a black box.

so hip it hurts,

clemens
===============================================================================
Clemens Suter-Crazzolara, PhD
Max-Planck-Institut fuer Zuechtungsforschung
Abteilung Genetische Grundlagen der Zuechtungsforschung
Carl-von-Linne Weg 10
5000 Koeln 30
Tel. xx49-221-5062.221           fax. xx49-221-5062.21
suter@vax.mpiz-koeln.mpg.dbp.de
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