G'day Team,

After reading a pathetically misleading clickbait heading on my facebook page recently I felt the need to clear something up regarding the truth behind the following "science" story.

The Article

Around this time last week, a new story started popping up repetitively on my social media pages. Americal astronaut Scott Kelly had apparently had 7% of his DNA altered while flying around in space, a fact we're able to recognize because his twin on Earth was there to act as a control.

Now, this is clearly not true... as many news outlets quickly picked up (1, 2, 3). In fact, a 7% change would mean old mate Kelly had returned a completely different species. So unless you're currently sitting in your mother's basement, wearing a tinfoil hat and browsing using Tor because "the CIA dude"... you're probably happy to believe Kelly is still human. So why did the media screw it up so badly? What exactly did happen to his DNA? And, what does this really mean for Kelly and space travel? That's what I want to have a chat about today!

But before we even get started... let's take a look at the comments section of the story above, just for fun!

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# Evadance

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Is 'reading the article' a foreign concept?

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Everyong! Quick! Stop sciencing... this guy's figured it all out

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...and this poor fellow :'(

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The Media is Shit at Science

This is no mystery... but why are they so bad? Well, it's simple, they get paid for getting reads. Not for producing accurate information, not for educating the public and not even for keeping people interested. They get paid for clicks, so they produce clickbait.

Even 'good' media outlets which put effort into their publications tend to put effort into odd areas when it comes to science. They put a lot of effort into beating up small findings into Earth-shattering news, or into ignoring the pieces of data that make their articles irrelevant. The problem here is generally one of two underlying flaws in the writing...

1. The writer doesn't understand science... they think that the new chemical compound which kills cancer cells in a petri dish can start getting pumped into patients next week.
2. The writer has an agenda... is it a cool summer in Ireland this year? CLIMATE CHANGE IS A LIE!!! COAL IS OUR FRIEND... you've all heard the rest!

In the Scott Kelly story, it seems to be a healthy dose of number 1 which has lead to the confusion... so where have the media gone wrong?

What the Media Reported vs. What Actually Happened

So here is what the media reported...

Scott Kelly has a seven percent difference in genetic makeup than his brother Mark Kelly after 340 days aboard the International Space Station

... so what does this imply? When I read this I think something along the following lines...

Holy shit! Space mutates our genes... Scott is a completely different person than when he went up. Will his kids, like, have super-powers? Also, maybe we could use this to make pokemon?

Unfortunately, this opening line is pretty blatantly untrue... and on so many levels too. What the report from NASA actually said was that there was a 7% change in how Scott Kelly's genome was expressed, when compared to his brother. In fact, while there were some structural changes in DNA coding (normal as mutations occur even on earth) these were nearly negligible and definitely nowhere near 7%... so what does this mean in layman's terms?

Imagine two identical libraries, both very popular with lots of readers, and both with lots of books. One library undergoes a renovation... let's keep it thematic, let's say it gets a space-themed mural outside. Well naturally intrigued by the mural, people start reading more of the books on space in the library. But both libraries are still identical, with the same books, it's just that at one library different books are being read more or less often than at the other. This is equivalent to the '7% change in genome expression' that Scott Kelly experienced. What the media reported, however, was that after the mural was put in place 7% of the books in the space-library were now space related. A magical change which had occurred due to the new art... now, this is clearly not true, and really not a sensible take on the whole situation either.

So what are the changes that did occur to Kelly's DNA? Well, they're called epigenetic changes, and they're a fascinating and rapidly evolving area of science... so let's have a chat about what they are and what they mean.

Epigenetics

At this stage almost everyone knows about the human genome, it's encoded by our DNA and consists of a large number of genes which essentially code for who we are. With the exception of the set of genes that make up our gender, almost all humans contain the same set of genes, but not all humans contain the same versions. For example, I may have a set of genes (called a genotype) which gives me brown hair, but my friend may have a genotype which gives him blonde hair. The difference here will come down to what the genes code for.

But there is another way that genes can differ between individuals, and just like our library example, it comes down to how the genes (books) are read, more than how they differ. The concept of changes in our make-up depending on how genes are regulated (enhanced, suppressed, tied to other genes etc.) is called epigenetics. The prefix "Epi" means "beside" or "nearby" and that's exactly what epigenetics is. It's a study that's very closely related to genetics, and together these two fields are responsible for looking at how we go from a sequence of approximately 3 billion nucleotides to a race of seven billion unique humans.

Scott Kelly's Epigenetic Changes

While it's still a developing field of research, it has become apparent in recent years that how our genome is read is not a fixed process. We've long known that the genome can have 'on' and 'off' switches attached to it in the way of molecules, called acetylation and methylation. What we've learned recently is these switches can change throughout our lives, depending on the individual stressors that our cells experience.

I've spoken about this before in my post on the regulation of muscle growth, and a cursory search in steem has shown that it's also relevent in arsenic exposure, childhood nurturing and possibly even obesity.

For a body in space, a number of changes in the physical environment (namely the lack of gravity) reduce a lot of the stressors on the body. Bones become less dense, the circadian rhythm is decimated, blood circulation changes and our coordination circuits in the brain have to adjust to a lack of gravity when making movements. The immune system is suppressed and the bacteria in our gut also change. The upshot of all this is that Kelly's physiology was different when in space, and his cells used their DNA differently in order to reflect this change.

This Research Wasn't Incidental

Interestingly enough, a lot of news outlets seem to have the idea that these findings were just a bit of a lucky coincidence. I mean, what're the chances of an astronaut with an identical twin sibling?

They're wrong here too. Kelly was sent to space deliberately as part of an effort to understand the impacts of prolonged space flight on the human body, largely in preparation for potential Mars missions. The fact he had a brother is also not a coincidence, and the research conducted upon his arrival was well prepared and planned far in advance.

The upshot of the research is that the changes the body experiences while in space do tend to stick around, and while we're not yet at the point of being able to determine how this will impact our Mars mission, one can imagine that something like low bone density might pose a problem on a small mars colony trying to manually construct a local habitat or explore the surface.

Thanks

As usual, thanks for reading team and I hope everyone learned something cool!

Thanks

-tfc

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