From: sil@ccieurope.com   
      
   "Raven"  wrote in   
   message news:r9EMb.5969$%k2.3391@news.get2net.dk...   
   > "Steen Eiler Jørgensen"  skrev i en   
   meddelelse   
   > news:40014a3b$0$139$edfadb0f@dread11.news.tele.dk...   
   >   
   > > Should human activity on Mars bio-contaminate the surface, it should be   
   no   
   > > problem for a trained biologist to spot the difference between   
   terrestrial   
   > > microbes and organisms never encountered before.   
   >   
   >    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.  Do microorganisms have enough junk DNA,   
      
   I wish people would stop calling the "non protein coding" part of DNA for   
   junk.   
   See e.g. Scientific American, nov 2003 for the latest on this.   
      
   >which is not subject   
   > to selection pressure, to establish kinship?   
      
   hmmm, again I think you are assuming junk here. As it is not (junk), it must   
   be fair to argue that there is selection pressure on these parts as well.   
      
   >    Also, there is the possibility that Earthlife has already been   
   introduced   
   > to Mars, a very long time ago.   
      
   And hopefully more to come!  Ok, lets scan Mars for life, but surely it   
   shouldn't hold back exploration of the planet.   
      
   -Simon   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)