This is an observational study, and you may be analyzing it as a designed one. There was no randomization, no large scale matched control group per se—that wasn’t the intention. The intention is to analyze a specific population, and compare it to the existing literature on prevalence of mutations. That’s how these things are done, you have to use the citations given to understand the broader context of a study. One study is not useful on its own.
Also, there’s this—they did hypothesis tests against a control group:
> Variants (SNP/ InDel) generated with this method were compared with a normal dataset using Archer’s analysis pipeline to distinguish noise from a true call. The normal dataset was created with sequencing data from seven young, healthy individuals.
I'm also not criticizing the study, I'm criticizing the article and your defense of it. If "you have to use the citations given to understand the broader context of the study" - then if the point of a pop sci article is to effectively communicate the salience of the paper to lay audience, then that broader context needs to be communicated too.
To put it concretely, if the chance of a random gene mutation is 10^-4 to 10^-6 per gene per generation, and there are 37 trillion cells in a human body, each cell containing about 20k genes, (all numbers from quick google searches) then the odds of having NO genetic mutations occur in your body in one day would be (forgive my back of the envelope math, assuming a generation is 20 years): (1 - 10^-6)**(37 trillion * 20000 / 365 / 20). My calculator can't keep enough precision to make this nonzero. i.e., everyone has genetic mutations constantly which makes the title of the article completely uninformative.
Germinal cells reproduce very slowly, so the eggs and sperm have fewer mutations.
Also, cells inside the guts have some cascade method. The cells near the wall reproduce very seldom, but the intermediate cells reproduce faster, and the inner cells reproduce even faster. The inner cells that are reproducing fast die or get washed away, so the big number of possible mutations is removed. And the slow reproducing cells near the wall create more cells to replace the intermediate cells that replace the inner cells.
And I would argue that the article (not paper) does _not_ convey the qualitative conclusion of elevated rates of nonstandard mutations, because it doesn't reference the baseline at all! It doesn't even present it as a comparison, like "We found MORE mutations in astronauts than would be expected of non-astronauts" - it literally just phrases it as "We found mutations in astronauts", which, considering that non-astronauts are exposed to radiation and get cancer + epigenetic mutations as well, doesn't differentiate it from the normal expected observation.