On 9 Sep 2001, at 14:10, Nick Arnett wrote:
> > AHA! Well..
> >
> > Your gut bacteria are NOT entirely benign tho. Like your normal skin
> > flora, if yu immune system is depressed for some reason, then you
> > can have an opportunistic infection from them.
> >
> > So it's not really symbiotic (neither side hurts the other), it's
> > mutralistic..if they have the chance, they WILL infect you...
>
> But isn't that just the way it is in any partnership? A spouse who
> doesn't assert him or herself will inevitably be taken advantage of by
> the other. Again, perhaps not intentionally, but that is the nature of
> things.
That's why, as I said, the term mutralistic is used for those
relationships today, rather than symbiotic.
> > As to mitochondia (and indeed chloroplasts in plants), this is the
> > BIG symbiotic relationship, which must have arrisen *millions* of
> > years ago. We are totallt dependent on them, and they on us - it's
> > not really selfish or altrustic though, as they are essentially a
> > part of ourselves.
>
> But isn't endosymbiosis as clear an example of collaboration in nature
> as one could hope for? It is a relationship that has so much mutual
> benefit that the two things became one.
You said it - they became one. Subject to basically identical
selecive pressures. If you seperated a mitochondria from a Animal
cell today, it dies - it dosn't have all the genes it needs to survive.
Thus, talking of selective pressures on them being different..well, I
don't think you can.
There is, to some degree, competition within the Human body, for
example in the brain as it forms in babies. Cells "try" to grow as
rapidly as they can, and in the end only the top 10% or so become
neural cells - the failures don't die, except as their potential to
become neural cells is coincerned, they become structural cells in
the Brain.
You have to beware taking compreition within the body too far.
Very _Earth_ isn't this :)
Andy
Dawn Falcon
