-- Peter L Borst <[log in to unmask]> wrote:
>...what is assured is that microscopic pathogens get better at
killing more quickly than their hosts.

i can recommend universally "the queen of trees" from the pbs nature series...everyone should watch this, and probably buy it.

one of the nice things about this video is that it demonstrates (in organisms that are big enough to see...with the aid of fantastic videography) the parasite/host relationship, and the symbiotic relationship between the fig tree and various wasp species.

if a parasite gets 'too good at stealing from it's host', it kills the host, and will threaten it's own survival.  too many parasitic wasps taking advantage of the fig wasp in a single fig fruit will make for a bumper crop of parasitic wasps...but if they leave too few male fig wasps intact, they will die inside the fruit without reproducing....selecting against traits that lead the parasitic wasp too infest a single fruit too heavily.

this same dynamic plays out with microbes....they strike a balance between stealing from their host and not killing the host.  this is in contrast with what was stated above, that 'pathogens get better at killing more quickly than their hosts'.  parasites can kill their hosts...but if they get too good at it, then there are no hosts left...and no parasites.

it's also worth pointing out that many microbes are beneficial and/or necessary....even parasites.  e. coli is both a pathogen in humans, and also a necessary symbiont. ...and remember, that even microbial parasites have microbial parasites that keep them in check. 

deknow

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