NASA has released preliminary results from the genetic study of twin brothers Scott and Mark Kelly:
The first results from NASA's Year in Space brothers are in, and show glimpses of how stressful a trip to Mars could be for the human body. Astronaut Scott Kelly captivated minds when he departed Earth in March 2015, bound for a yearlong stay at the International Space Station. Part of the excitement surrounded an experiment with his twin brother Mark Kelly, a retired astronaut who stayed on Terra Firma. At this week's NASA Human Research Program workshop, researchers revealed that the trip created contrasts in their genes' regular activities.
[...] Genomic data was taken before, during and after Scott Kelly launched to the ISS aboard a Soyuz rocket in Mar. 2015. He returned in 2016, after spending 340 consecutive days in outer space. A future mission to Mars would take at least 9 months, but a round trip would be 500 days. Scott's gene expression and DNA methylation fell back to their pre-flight status shortly after he returned from the space station. What this means exactly is still unclear, but scientists are eager to learn more.
Also at The Verge.
(Score: 1) by shrewdsheep on Wednesday February 01 2017, @01:41PM
... they are twins no longer, as their age differs by now.
(Score: 3, Touché) by bob_super on Wednesday February 01 2017, @06:54PM
So... technically, they are no twins, unless they get pulled out of mommy together, and always kept side-by-side during any movement?
(Score: 2, Touché) by Lester on Wednesday February 01 2017, @07:52PM
They are clones. It just happened that the natural spontaneus clonation process produced two clones at the same time, so the same age. Now there has been a little divergence.