Human Genome More Like a Functional Network
bshell writes "An article in science blog says we may have to rethink how genes work. So called "junk DNA" actually appears to be functional. What's more it works in a mysterious way involving multiple overlaps that seems to be connected in some sort of network." From the article:
"The ENCODE consortium's major findings include the discovery that the majority of DNA in the human genome is transcribed into functional molecules, called RNA, and that these transcripts extensively overlap one another. This broad pattern of transcription challenges the long-standing view that the human genome consists of a relatively small set of discrete genes, along with a vast amount of so-called junk DNA that is not biologically active.
The new data indicates the genome contains very little unused sequences and, in fact, is a complex, interwoven network. In this network, genes are just one of many types of DNA sequences that have a functional impact. "Our perspective of transcription and genes may have to evolve," the researchers state in their Nature paper, noting the network model of the genome "poses some interesting mechanistic questions" that have yet to be answered."
Its what we in the programming field would call the Data Segment.
Whenever I read something like this, I get a reminder how poor is biologists' comprehension of Computer Science, Information Theory, and languages.
Whenever I read a post like this, I get a reminder how poor is most techies' comprehension of biology, and more specifically, what biologists do.
Third, why this obsession with zeroing in on a magic gene that causes X? Do they think the language of DNA is context free? Defects could indeed be expected to have no context, but for the rest-- which genes determine a person's blood type? Eye color? Skin color? Going about that task by trying to find the magic gene for something like that is like a person who never learned to read trying to figure out the plot of a book by trying to recognize patterns of letters.
Okay, why do we care? Because finding the genes (note my use of the plural there) that influence certain traits is the first step toward understanding the overall processes that create them. Obviously this is most critical in the area of genetic disease, although it's interesting for everything else too. We've known for decades that most traits, including diseases, aren't controlled by a single "magic gene." What statistical geneticists try to do is find locations on the genome which have a strong relationship to the trait of interest. And we know perfectly well that there will be a whole bunch of these locations for most traits, and that some of them may represent genes and some may represent something else. The purpose is basically to give the wet-lab biologists something to zero in on.
Second, two of the examples you chose -- blood type and eye color -- are really terrible ones for your argument, because genetically speaking they're very simple traits (two or three loci each, IIRC) and, at least in the case of blood type, we know exactly where they are in the genome. Eye color I'm not sure about, and skin color is a little more complicated, but not a whole lot more so.
Please do not confuse the pop-sci "scientists seek gene for X" writeups with what really goes on in the world of genetic research. It has exactly as much to do with real science as TV portrayals of hackers have to do with real computing.
The correlation between ignorance of statistics and using "correlation is not causation" as an argument is close to 1.