> To: virology at net.bio.net> From: "Patrick O'Neil" <patrick at corona>
> Subject: Re: HIV-1 vs HIV-2
> On 15 Mar 1995, RYBICKI, ED wrote:
>> > > The most parsimonious scenario of all has an HIV ancestor
> > Whaaaaaaaat? Says who?! All of a sudden, HIV has been in
> > for a thousand odd years, and gets BACK into simians??
> Not really. More jumps are required, based on sequence
> one starts with SIV (as seen in chimps) and then assumes a jump to
> Low pathogenicity within a host doesn't necessarily a "better"
> If selective pressures within a natural host population favor
> transmission and pathogenesis, then it will develop in that
> regardless of how long the virus has been floating around within
This seems to be a new "current wisdom" - which does not necessarily
invalidate the old, which held that the milder a virus was in its
host, the better adapted it was.
But two excellent replies to my followup, sorry I have to do this
thru the group, but the address for Patrick (note: not O'Neil B-))
doesn't work from my server. Thanks Patrick!
> Low pathogenicity within the host might just as well indicate a
> move into that population, meaning that the virus hasn't quite
> for maximum efficiency within that host, just as an overly high
> pathogenicity could mean the same thing IF it reduces the rate of
> successful transmission.
| Ed Rybicki, PhD | (ed at molbiol.uct.ac.za) |
| Dept Microbiology | University of Cape Town |
| Private Bag, Rondebosch | 7700, South Africa |
| fax: xx27-21-650 4023 | tel: xx27-21-650 3265 |
| URL: http://www.uct.ac.za/microbiology |