Quote Originally Posted by Tvtyrant View Post
I think you should take the couple hundred and add thousands to it. "leave this alone to see if it does anything and then maybe in a couple hundred thousand years it will have spread enough that there will be breathable levels of oxygen in the atmosphere."

The problem with space colonies in my mind is the processes to terraform a planet are absurdly slower then the extinction rate is. IE we will almost certainly be dead by the time anything is even remotely habitable.
I imagine that there would be periodic missions to seed and reseed various parts of the martian surface with photosynthetic life able to survive on it that are cultivated by various colonies.

Ideally, by the time we can colonize mars we'll be able to engineer a plant or algae that grows like kudzu while needing little water and efficiently photosynthesizes.

But mars colonization is perhaps a topic for another thread.