Pairs of human chromosomes. Highlighted in green is alu, a 'junk' DNA sequence that distinguishes primates from other mammals.
Credit: Public Library of Science
"What's a gene, dad?" I'd like to be there when the nine-year-old son of iconoclastic geneticist John Mattick pops the question. It used to be simple - a gene coded for a protein.
But when I put that question to Mattick, based at the University of Queensland, his response was as disturbing as it was confusing.
"Genetic information is multilayered and a gene can convey lots of different information into the system. It's almost like we've moved into hyperspace in terms of information coding and transfer."
Mattick's cutting-edge theories about gene regulation have been published in the British journal Nature and even appeared in the New York Times. Yet, even though I was once a geneticist, I couldn't fathom his answer.
It seemed my fears had been realised and I'd been left behind by the genetics revolution. In a desperate ploy to catch up, I asked how he would explain a gene to his young son.
"I would just tell him, 'it's an old-fashioned concept', and then explain about information networks. He's a child of the digital generation - he won't have any trouble with it."
It's not just me who's confused. I checked the 2008 edition of my favourite text book, Molecular Biology of the Cell.
The traditional definition is still there in the opening chapter. But as you read on, you sense the textbook struggling, trying to wrestle the gene back into the box of a definition.
Mattick prefers not to try. And a lot of other geneticists are starting to think this way too. As Ed Weiss at the University of Pennsylvania told me, "the concept of a gene is shredding".
The genomics revolution is largely to blame. Scientists were shocked when they found out how few 'old-fashioned' genes we actually have - about the same number as the humble nematode worm (Caenorhabditis elegans).
In fact, almost all multicellular creatures with the complexity of a worm or greater have about 20,000 genes. But for Mattick, the death knell of the traditional concept of the gene was triggered by another revolution altogether - that of the digital information age.
Scientists have always understood biology in terms of the technology of the day. The brain, for instance, was considered by the Ancient Greeks and Romans to be an aqueduct for pumping blood; inhabitants of the 19th century likened it to a telephone exchange; those of the 20th century likened it a personal computer. Now scientists compare the brain to chaos and distributed functions of the Internet.
Junk you wouldn't want to be without
Absolutely brilliant work by the scientist and a thoroughly engrossing article.
The trouble with genes
It seems to me, that the assumption that anything in nature can be junk, 'feels' wrong.
On planet Earth there are no junk plants, junk insects, or junk animals etc.
Everything has a purpose and serves a function, like the symbiosis of flowers and bees. And if it doesn't initially have a purpose, it eventually fills a niche. Creating ecological cycles, and a balance in biodiversity. So why would DNA, RNA or anything else in nature be there for no reason.
Just because we don't understand something, does not mean we should just disregard it.
It seems Mattick is on the right path, including all aspects of a particular phenomenon into the equation.
Peace,
no quizzle
GREAT ARTICLE
Thank you Elizabeth Finkel for this wonderful guide to the complexity of current genetics.
Yes I agree: Thank You Elizabeth
I was struggling with all the new information about DNA RNA and junk etc, but I am on the way now to understanding and all because you wrote an inspired explanation on what continues to fascinate many of us. Don't stop there; we will need more of these clarifying essays, I am bound to get confused again, at least I hope so.
Junk Bunk
We categorized 'junk' DNA or Interons as useless and finalized our conclusions without ANY evidence whatsoever. Yes, we were really applying science on that one.
New definition of science: No longer from scientia "the state of knowledge," but NOW really what has occurred over the last 2000 years "the state of disproving 'knowledge'." We have too many so called scientific principles which are just approved people citing and referencing statements from other approved people. Once a statement gets cited over 13 times it becomes authorized knowledge, until science gets off its butt and disproves authorized knowledge.
Isn't this bassackwards? Shouldn't we declare a necessity of plurality (not sit back and wait for proof like arrogant sloths) and go and research an issue before we declare it solved?
The Scientific Method
1. Get a degree
2. Make something up
3. Get enough people to cite your creation
4. Basque in the science you have created
5. Die
6. Another person, free from your oppression, makes something else up.
OCKHAM (did I shave today? I forget.)