Does going into space fundamentally change our biology? It’s not a casual question. Human beings evolved to live in a very specific ecological niche, and no matter how tough DNA is, nature never planned for us to sit on a pile of explosives and fling ourselves into an airless void full of rocks and ionizing radiation. So NASA took a rare opportunity, using twin astronauts, to study how being in space affects our genome. And there are some strange results for scientists to chew over.
Scott and Mark Kelly, identical twins, participated in a study in which Scott spent a year in space while Mark stayed on Earth. NASA collected blood and other tissue samples and is still running a battery of tests on everything from gut flora to genetic variance, but the preliminary results are in and there’s a lot to think about. For example, it was theorized that being in space for long periods of time would shorten your telomeres, which “cap” your chromosomes and prevent genetic damage. Instead, they lengthened while in space, and returned to normal fairly quickly when he came back to Earth.
DNA methylation, meanwhile, a way for your body to control DNA activity without changing your DNA sequence, went down in Scott, but up in Mark. Gene expression signatures were also different, but that tends to reflect your lifestyle, so right now, that’s being chalked up to an astronaut’s life of freeze-dried food and no sleep.
What does this mean for space travel and potentially going to Mars? Right now, we’re still figuring that out, although it seems all but inevitable that this will mean more rigorous medical testing will need to be done, and we may need to work out the long term consequences. One thing is clear, though: the longer you’re in space, the more it changes your body.
(Via New Atlas)