Terraformation of Mars to Create New Human Race?

I watched an interesting program on OPB called Exploring Space: The Quest For Life. It talked about the possibility of terraforming mars. The theories of terraforming mars isn't anything new (1) (2) (3) and is highly debatable whether it's even possible. But the interesting part of the show was the discussion about the long term effects on the human body from colonization of Mars. They attempted to analyze just the effects a lower gravity would have on the human body over countless generations. They showed evidence from studies done regarding short term effects of zero gravity, most evidently was the loss of muscle mass especially within the human heart. Since the heart isn't constantly fighting the effects of gravity to pump blood around the body it doesn't need to maintain the same muscle mass. It went on an on to show how the body would change and adapt to new conditions. If humans still inhabited earth while new colonies procreated on mars, eventually you would end up with two entirely different humans. Each generation of martian human would have a harder time returning to earth as they wouldn't be used to the greater gravity, it could even start to be fatal for them. The whole thing brings up so many interesting questions: - Would those changes be for the better or worse? How would we handle that? Today we have enough problems with people fighting each other due to differences in culture, racial, religious, sexual orientation, etc. Would our worlds grow apart making another difference to provoke war? Or would it help to create a better future? - If you had the choice to move to a new world, making a choice for all your future offspring, would you go? I guess that would be the type of decision many of our ancestors had when faced with a choice to travel to America. What are your thoughts?