Finding gene activity differences in identical twins, Ars Technica
"They're called identical twins because their genomes are identical. But even though all of their DNA is the same, they clearly are not. The environment must play a role in how identical twins and everyone else uses their genes to become who they are."
"A multitude of human research investigations currently are underway and are scheduled for upcoming expeditions aboard the space station by NASA and its international partners. The opportunity to compare the effects of spaceflight accumulated over one year and observe changes in the genetic makeup between twin brothers is new. These investigations could have lasting implications for protecting astronauts on deep space exploration missions, including travel to asteroids and Mars."
Keith's note: NASA has spent a lot of time hyping the whole twins thing. It is important to note that "identical" twins are not identical. Just take that face-to-face photo of the Kelly twins (larger view), flip one image, superimpose it on the other, align for facial features and look what you get: altered skull shape (ergo brain shape) and ear shape and placement. But they are identical - how did that happen? Hmm. Prenatal environment is likely the prime factor but other things during their early lives could be at work as well. To be certain the Kelly twins are vastly more alike at the genetic level than this crude photo comparison might suggest. But they are not identical - and they become less identical with every passing day.
This one-off, 342 days in space thing is not going to reveal the multitude of mysteries that are blocking NASA's trail to Mars - as NASA wants you to think it will. Certainly no more than John Glenn's flight solved the mysteries of aging that NASA PR hype claimed it would. If NASA wanted to do real science they'd find a pair of twins and fly one in space and never fly the other. And then they'd repeat it multiple times with other pairs of twins. There will be interesting data - that is certain. But will this research move NASA down the road to Mars? If so, not by very much - if at all. At best, these Kelly brother studies will show the difference between a little spaceflight (54 days spaced across 4 short missions) and a lot of spaceflight (540 days - two long ISS stints and a shuttle flight) on one genome that operates in two different bodies.
Why not put a bunch of people on ISS - the size of a Mars mission crew - all at the same time - for the 2-3 years needed for a round trip to Mars? Better yet: let them spend a year or so on ISS, dump them immediately in the arctic (on their own) for 6 months to do field work - and then put them back on the ISS for another year or so. THAT would be far more useful in terms of flight certifying humans for a trip to Mars and back than this twins study.
The reason why NASA can't or won't send people to Mars is because NASA has not decided to actually try to send people to Mars. No one in the White House, Congress, or NASA is serious about this. Everything NASA claims to be doing in that regard right now (such as ARM and the twin studies) is just smoke and mirrors. #YearInSpace is just the latest installment in this pretense that anyone is actually trying to send humans to Mars at NASA.