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Re: dino extinction



In article <v01540b0caeb7dfd80195@[129.127.84.36]>, Stan Friesen
<swf@ElSegundoCA.NCR.COM> writes
>From: Rob Meyerson <meyersrt@uwec.edu>
> > ...  Despite how
> > Bubonic Plague ravaged human populations, I am unaware of any other species
> > that were affected to the same degree (were the rats that carried the
> > plague-fleas killed as readily?).
>
>Not that I know of.
>
>In fact high survival rates in the rats would contribute to
>making them more effective vectors of the disease. (Each rat
>would infect more people the longer it lived).

er, rats are the reservoir of plague bacteria (T.pestis) and flees are
the vectors. Rats die as quickly as humans after being infected and
the flees then leave the dead rats to seek other warm blooded hosts,
usually other rats but in urbanised areas often human. Flees wont
leave a live rat, infected with plague or not.

[I'm not sure about the rat part, but I was planning to comment on
 this thread.  See:
 http://www.sciencemag.org/science/scripts/display/short/273/5273/367.html
 In the wild type of the bacteria responsible for the plague
 (_Yersinia pestis_), infection causes a pretty awful death for the
 fleas as well.  The bacteria colonize the foregut making it impossible
 for the flea to swallow.  The flea thus starves to death even as it's
 repeatedly biting into its host -- it can't get food past the
 bacterial colony.  Naturally every one of those bites provides the
 bacteria with a chance to jump to the other host.  Note that this
 also puts the lie to Rob's claim that disease causing organisms are
 tightly targeted.  But I still think Bakker's full of hooey with his
 views on dinosaur extinction.  Now back to your regularly scheduled
 program...  -- MR ]

Gautam Majumdar         gautam@majumdar.demon.co.uk