This research group (3 universities - Simon Fraser and two from the States) used one of the standard genetics model organisms to test the long-term effects of space travel. Basically, a trial run so we know what to expect (or protect from, or deal with) if we send humans on an extended space mission (i.e. to Mars).
It sounds really interesting. :) C. elegans is a small worm with a short (couple of weeks) life cycle. So in the six months the worms were in orbit, there were 12 generations. One of the ongoing studies is testing the descendants (now back on planet) for mutations caused by space radiation. Interestingly, the muscle degeneration seen in low-gravity environments does indeed plateau. (makes sense to me, as you're still using at least _some_ muscle power to move around, but it was a concern that needed to be addressed)
So, go read the
CBC article. Or better yet, the
full paper. :)