I know that there has been tiny, single cell organisms found in extreme climates. Does that mean that we could have

Question: I know that there has been tiny, single cell organisms found in extreme climates. Does that mean that we could have arrived on earth on an asteriod and then slowly evolved to what we are today?
- Keywords:
  asteriod,
  cell,
  climate,
  evolution,
  extreme,
  organism
Asked by dognut99 to Ed, Hayley, Jason, Nathan, Sophie on 12 Mar 2013.
- Hayley Evers-King answered on 12 Mar 2013:
  
  What you mention is a theory called “panspermia” – the idea that life came to Earth on an asteroid and was seeded here to evolve to current life forms we see. The fact that life can exist in extreme climate certainly suggests it’s possible it could survive the harsh environment of an asteroid travelling through space. Until we find evidence of life on asteroids it will probably have to stay a hypothesis though. But I think this raises another interesting question – if life was seeded here by an asteroid, where did it come from originally?

Question: I know that there has been tiny, single cell organisms found in extreme climates. Does that mean that we could have arrived on earth on an asteriod and then slowly evolved to what we are today?