No, Really, It’s Just Junk

I’ve been getting my little science news snippets these days from Science Now news (Science Magazine, unfortunately restricted access) and Nature News (unrestricted access). I look around for other news sources, I know there’s a ton out there. Today I looked at Seed magazine’s news.

The top article at the time was this one: “Junk (DNA) In The Trunk“.

The article’s opening paragraph…

“Finding a function for the 98.5 percent of our DNA that doesn’t encode for proteins – sometimes known as “junk DNA” for its jumbled, illegible arrangement – became a little less elusive last week. Geneticists from Johns Hopkins published an innovative way of using zebrafish embryos to test the purpose of non-coding human DNA sequences in the March 23rd online issue of Science Express.”

Oooooh, how mysterious! We don’t understand 98 percent of our DNA!

Actually, it’s not.

It’s not a mystery.

It’s a bunch of repetitive elements, parasitic self-propagating sequences that occassionally, in frenzied bursts of self-centered replication, manage to insert copies of themselves all around the DNA. They’re called transposons. 72% of our DNA is composed of retrotransposons, LINEs, and SINEs, three varieties of selfish, self-propagating junk.

This is just bad reporting. People should not propagate the mystical idea that there’s vast tracts of presumably functional DNA that remain a mystery to scientists. It doesn’t need a function! We’re pretty sure it doesn’t have much function. This sort of thing is vexing enough when it takes the form of science fiction but it’s totally unacceptable in science reporting.

Of course, the reporter did not actually get any facts wrong. He simply missed the point.

This really is something interesting here. Transposable elements have been a great tool for analysis of transcriptional promotion for Drosophila, and zebrafish is an animal much more relevant. What we really care about here isn’t the junk. We care about transcriptional regulatory elements, those small regions preceding genes, and maybe a few small distal elements, that determine when a gene is going to be expressed.

So, yes, there are interesting noncoding portions, but to conflate that with the 98.5% number and the term “junk DNA” is going to propagate the ignorant characterization of this stuff as being of mysterious function, when we’re pretty damn sure it ain’t.


… And, as if the world conspires to drive me apoplectic, Chris sent me a link to this article about the in silico simulation of a virus. But… what’s the point? I mean, sure, it’s an impressive computational feat, but what did they learn? The article failed to report on the results!

Here it is, in a quote from Nature News:

“The model also shows that the virus coat collapses without its genetic material. This suggests that, when reproducing, the virus builds its coat around the genetic material rather than inserting the genetic material into a complete coat. “We saw something that is truly revolutionary,” Schulten says.”

See, that’s an interesting result. The LiveScience reporter missed it.

Science reporting shouldn’t just be about mysteries and pretty toys. I wish science reporters didn’t keep misunderstanding science and missing the point of research — not just for the layman’s sake, but mine too, because I like reading about this stuff.

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