Just guessing but what if Hiro or Peter traveled back in time in their quest to "fix" the problems in the series and inadvertantly created the SG Gene pool?
Hiro has already shown a great drive to correct the future as he thinks it should be.
We have seen multiple futures already that have directly been influenced by him.
The long term scheme of things could easily involve him or Peter going back and starting the whole species.
Input requested and looking forward to alternate opinions.

Sorry but, I hope that doesn't happen. I wouldn't want to see people evolving into mutants because of a time paradox.

Me neither but it seems every "time altering " movie or show eventually leads up to the characters creating the situation that they are trying to avert.
I hope that Heroes avoids that but aside from alien DNA or some type of divine intervention, I don't know where else they may go.
Any ideas?