From: oz1sejREMOVETHIS@get2net.dk   
      
   Raven wrote:   
      
   >    Not necessarily.  If Terran microorganisms are introduced to Mars,   
   > and some of them survive and actually grow, they will be subject to   
   > an enormous selection pressure.  A few decades might change them   
   > beyond easy recognition.   
      
   "A few decades" - most certainly. I don't see it as a problem for the first   
   handful of human missions. Besides, you wouldn't start looking for Martian   
   life right below the habitation module. You'd probably go hundreds - perhaps   
   thousands - of meters away from the base. Considering that the Martian   
   surface is very hostile to organic life (oxidizing agents in soil, strong UV   
   radiation), the probability for terrestrial germs to blow around in the wind   
   AND for us to discover these germs is very small.   
      
   >    Also, there is the possibility that Earthlife has already been   
   > introduced to Mars, a very long time ago.  Imagine a large meteorite   
   > strike on Earth; some of the ejecta somehow reaches Earth escape   
   > without being cooked, and Terran microorganisms survive in   
   > hibernation, well protected within the rock.  Then this rock impacts   
   > Mars, in such a way that the central parts of the rock is not cooked.   
   > Discovering Mars-life with this particular kinship to Earthlife would   
   > be a considerable scientific find.   
      
   Absolutely. But I see it this way: If Mars is - or was ever - capable of   
   sustaining life - and that's what we're trying to figure out - traces of   
   this life should be present all over the planet. The idea of Mars as overall   
   frigid and sterile, *apart* from unmistakeable signs, only found in e.g. the   
   Hellas Basin, that Mars supported life long enough for it to develop, is -   
   as I see it - extremely improbable. If life ever evolved on Mars, we should   
   be able to find traces of it over most of the planet.   
      
   Of course, if we find only small traces of what could appear to be   
   terrestrial life brought to Mars billions of years ago, we'd probably find   
   it only in specific locations.   
      
   --   
   Steen Eiler Jørgensen   
   "Time has resumed its shape. All is as it was before.   
   Many such journeys are possible. Let me be your gateway."   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)