Via Daily Caller:
NASA astronaut Scott Kelly returned to Earth after a year of space travel and new studies reveal that his DNA is now different from that of his identical twin brother, Mark Kelly.
The results of the NASA study show how the physical and mental impact of living in space for a year can significantly change the human body.
“Researchers learned that spaceflight is associated with oxygen deprivation stress, increased inflammation, and dramatic nutrient shifts that affect gene expression,” NASA’s website explains.
The telomeres, or caps, of Scott’s chromosomes (which aid the human aging process) lengthened as a result of space travel. Ninety-three percent of Scott’s DNA has gone back to normal after landing, but seven percent still appears different from his identical twin brother’s. But not all changes were internal.