In article <Pine.ULT.3.91.960829234509.7415Gfirstname.lastname@example.org>, David Beorn <email@example.com> wrote:
> On 27 Aug 1996, Joan Shields wrote:
> > Just look at how variable HIV is. All these mutations all occuring at the > > same time - some are viable and some aren't. Some are better at surviving > > for a while or better at transmission or better at eluding drugs and the > > body's own systems. > > But in all cases, it is STILL HIV, right?? I.e. no evolution occurred - > adaptation, variability of a species yes - but not evolution. No new > "creature" was created. > I am somewhat hesitant to become involved in this thread, but here goes:
HIV has evolved and continues to evolve. There is substantial molecular evidence that HIV is closely related to immunodeficiency viruses (called SIV) found in nonhuman primates (vervets, macaques, mandrills, Syke's monkeys and chimps).
You appear to be somewhat confused between speciation (the processes that generate new species) and evolution. I am not really prepared to discuss what constitutes a "species" of virus, but it is clear that by certain criteria HIV constitutes a different creature than SIV. I would postulate that the processes involved in the generation and selection of the variation in HIV are not qualitatively different from those that led to the transformation of SIV to HIV (or SIV to HIV, the data are still somewhat equivocal on this detail).
_____ Jerry Learn
Dept. of Microbiology | Learn@u.washington.edu University of Washington | Phone: (206) 616-4286 Box 357740 | Seattle, WA 98195-7740 USA | FAX: (206) 616-1575