[meteorite-list] Panspermia and Mars back contamination
From: Mexicodoug <mexicodoug_at_meteoritecentral.com>
Date: Sat, 06 Jun 2009 04:20:21 -0400
"Pathogens and their hosts are, quite literally, made for each other."
I understand this statement but disagree with it in the terms of the
current debate. It presupposes our thoughts from our experience with
life on earth and the equilibrium life has here. At a basic level we
are just bags of sugars, proteins and fats. Detritus on earth can be
eaten by millions of organisms - just about any organic materials and
then there are even critters that can deal with sulfur and nitrogen
bases in extreme environments.
How many microorganisms can live in detrital composts on Earth? What
prevents them from eating organisms that are alive? It is more a one
way protection developed by the living host in this convergence, but
not necessarily a handicap for the invasive. If the host had no basis
for an immune response, microorganisms would eat people alive just as
easily as detritus on Earth, like the massacre that happened during the
Spanish Conquest of Native America.
I guess the question you might raise is: But if Martian microbes had
nothing like flesh to eat how would they suddenly become human
flesh-eating nanobacteria or whatever, here? Given the harsh Martian
environment they ought to be fairly omnivore and if we are presupposing
some kind of cellular life (this being subject to another debate) I
don't see it as far fetched. Really, if the "Martian pathogen" found
anything at all to eat on the smorgasbord of
earth it could trash our
ecosystem by hitting any level of our equilibrium without being harmful
at all directly to humans. It might even be passive and like our oceans
and be super-photosynthetic, and as an example peacefully co-exist
except for non-stop peeing of cyanide or something such, into the
oceans...a la movie Sunshine (2007), the greenhouse in the Icarus 1.
PS, the good thing is ... scientists, instead of our immune systems,
probably could devise treatments fairly easily, pretty much due to the
absence of "being made for each other" (= able to fight back via
convergent evolution) cited.
From: Chris Peterson <clp at alumni.caltech.edu>
To: meteorite-list at meteoritecentral.com
Sent: Sat, 6 Jun 2009 1:05 am
Subject: Re: [meteorite-list] Panspermia and Mars back contamination
>The whole fear that return samples from Mars, either?
>by robotic mission or manned, seems thoroughly irrational to me.?
I think that's a little extreme, but I certainly agree with you that
any life on Mars is very unlikely to be pathogenic. On Earth, only a
tiny percentage of microbes are pathogens, and the majority of those
have evolved as such in concert with our own evolution. Pathogens and
their hosts are, quite literally, made for each other.?
Still, some microbes are incredibly hardy, and the potential that
something from either planet might become an invasive=2
0species on the
other (with unknown environmental consequences) should at least be
taken into consideration when designing missions. If nothing else, any
cross contamination could thoroughly ruin the quality of science that
can be performed.?
Chris L Peterson?
----- Original Message ----- From: "Rob McCafferty"
<rob_mccafferty at yahoo.com>?
To: <meteorite-list at meteoritecentral.com>?
Sent: Friday, June 05, 2009 5:38 PM?
Subject: Re: [meteorite-list] Panspermia and Mars back contamination?
> On a more realistic note...(though I applaud the jocularity)?
> The whole fear that return samples from Mars, either by robotic
mission or > manned, seems thoroughly irrational to me.?
> The very idea that a microbe that MAY exist on present day Mars that
will > have spent 3 Aeons adapting to a cold, dry, low atmospheric
pressure, slow > metabolic existence would thrive inside a human body
seems, frankly > ludicrous.?
> On earth, extremophiles can only exist in their own little niches
because > once they are out of them, they either die from conditions or
competition > from better adapted organisms.?
> Given the opportunity to go to Mars, I'd be there like a shot and I'd
take > my chances.?
> As for Greg's Martian Champagne. I20can't help feeling we have an idea
for > the latest "trendy" craze to part overpaid footballers (soccer
players) > from their cash.?
> I reckon you could get these self centred egotists to pay ?300 ($500)
for > a glass of "Rock Rose" or "Selene Rum" (registered trade marks,
patent > pending) as they attempt to impress their friends/one night
stands and > probably make enough money in a month to retire on in
> I'm gonna be rich?
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Received on Sat 06 Jun 2009 04:20:21 AM PDT