I was telling my boyfriend about a dream I had last night. In my dream, scientists were alarmed to find that Mars researchers returned to Earth with differently-shaped skulls because gravity be crazy. In response, my boyfriend mentioned reading an article about astronaut Scott Kelly’s DNA changing after spending a year in space.
For anyone who isn’t familiar with Kelly, his story is really interesting because he has an identical twin, Mark Kelly (also an astronaut). Because of this, researchers can monitor the effects of space on the human body by comparing their identical DNA in addition to their overall physical health – pretty cool stuff.
Of course, I immediately had to see what my boyfriend was talking about. DNA changing in space? That discovery would be a real game changer, especially as visionaries like Elon Musk look to someday colonize Mars. What if someone spent several years on Mars? Would they come back looking like this?
I found this article with the shocking headline, “Astronaut’s DNA changed by time and space” and this one which reads, “Astronaut Scott Kelly is no longer an identical twin: How a year in space altered his DNA”.
Is it true? Is space everything Mulder dreamed it would be? Is the truth really out there!?
As usual, the headlines are exaggerated. Darn. I’ll be back here with Scully.
Kelly himself tweeted the story with the joke, “I just learned about it in this article. This could be good news! I no longer have to call @ShuttleCDRKelly my identical twin brother anymore.”
This article on Gizmodo does a really good job of breaking down the findings.
They noted, “…if 7 percent of Scott Kelly’s DNA actually changed, he would be a completely different species. Humans and chimps, for example, share 96 percent of the same DNA, a 4 percent difference.”
What really happened is that 7 percent of the way Kelly’s DNA is expressed changed after space travel, as Daniela Bezdan, research director of the Mason Laboratory of Integrative Genomics at Weill Cornell Medicine, explained in a tweet and confirmed in an email to Gizmodo. This is further confirmed in an expanded statement from Chris Mason, who writes that, while there were some mutations in both twins’ DNA after spaceflight, “although 93% of genes’ expression, returned to normal postflight, a subset of several hundred ‘space genes’ were still disrupted after return to Earth.”
This kind of change is what’s known as epigenetic, and it is something very different.
Space might affect methylation, for example—the act by which chemistry flips DNA sequences on and off, making them readable or unreadable by the rest of the cell. It’s as if DNA were an encyclopedia, with some sentences covered with black tape, making them unreadable. The trip to space could have switched some of the tape around—but the words are exactly the same.
So the findings are fascinating for sure, but the Kelly astronauts are still identical twins and won’t be turning green or reading minds anytime soon.