Junk DNA: Reverting to Junk Science
Anyone who reads this blog (all two of you) knows that I love Doctor Who. Whenever I try to recount the plot of an episode I've seen, I'm left realizing that to the uninitiated, the show sounds absolutely nuts. (Unless we're talking about the rogue episode "Love & Monsters" then I'd agree, not one of their better ones.)
But I must register a complaint about the episode I've most lately seen, "The Lazarus Experiment". You see, for once when the Doctor blurted out an explanation (regarding the mutated scorpion-like monster with a human face clawing and trying to consume him and his companion) I understood him. The idea was that the beast was a man who'd put himself through a machine to alter his DNA and make him young again, but the Doctor notes that in doing so, he activated so-called "junk DNA" in his code.
Supposedly, scientists think that we still have non-coding portions of DNA in our genes, and since they consider us products of millions of years of speciation, they think our genetic code is like a refrigerator that's been neglected for weeks; chock-full of useless leftovers.
Star Trek and other shows have played off this idea, suggesting (at least in fiction) that by mutating the genes, they can somehow reactivate so-called extinct portions of the code and revert the human back to an evolutionary ancestor. Star Trek: The Next Generation had an episode based on this folly, where members of the crew were (re)turned into various primordial creatures.
The idea of junk DNA is based on one and only one scientific fact; scientists haven't identified or don't yet understand the functions for between 90% and 98% of our genetic code. Given their assumptions about evolution, they automatically assume that absence of identified function is an identified absence of function and brand it "junk DNA" and unworthy of further research.
But they're so wrong.
Back when I was arguing this topic more heavily, I set up an RSS feed for news articles that talked about junk DNA; it was an area of special interest because any scientist who stepped past his or her preconceived notions were constantly debunking this idea of junk by finding function for portions of the genome that they didn't know existed.
A list of assorted articles from 2007 about finding function in DNA
Article admitting evolutionary assumptions about DNA get in the way of research (Also notes finding function)
Some nice headlines from March '09 about junk DNA
(Trust me, the above merely scratches the surface. There are some archives here and here on the subject. A visit to junkdna.com might prove enlightening as well.)
In fact, I predicted to myself after starting this blog entry that I could return to my RSS feed and find very recent functions of "junk DNA" uncovered. My prediction was validated...
'Junk' DNA Proves To Be Highly Valuable (Science Magazine, June 2009)
So-called junk DNA may not be junk at all (May 2009)
Doctor Who episodes are always absurd, but always delightfully entertaining. A bulwark of creative genius engineers those plots, and the resulting strangeness just smacks of that peculiar strangeness that truth often has. But sometimes the suspension of disbelief is a fine line for me, and when the Doctor offers an explanation that even I know is scientifically false, it jars that suspension just slightly.