'Junk DNA' News

Junk DNA turns out to influence diabetes risk

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Further to “Another pseudogene shows function”:

Variations in non-coding sections of the genome might be important contributors to type 2 diabetes risk, according to a new study.

DNA sequences that don’t encode proteins were once dismissed as “junk DNA”, but scientists are increasingly discovering that some regions are important for controlling which genes are switched on.

The new study, published in Nature Genetics, is one of the first to show how such regions, called regulatory elements, can influence people’s risk of disease.

“The cells that produce insulin appear to be programmed to behave differently in people with type 2 diabetes,” said co-author Mark McCarthy, a Wellcome Trust Senior Investigator at the University of Oxford. “This study provides some important clues to the mechanisms which are disturbed in the earliest stages of the development of type 2 diabetes, and may point the way to novel ways of treating and preventing the disease.”

Is someone keeping track of all this for an Atlas of Junk DNA?

Memory bank: “The amount of DNA in organisms,” neo-Darwinist Richard Dawkins wrote in 1976, “is more than is strictly necessary for building them: A large fraction of the DNA is never translated into protein. From the point of view of the individual organism this seems paradoxical. If the ‘purpose’ of DNA is to supervise the building of bodies, it is surprising to find a large quantity of DNA which does no such thing. Biologists are racking their brains trying to think what useful task this apparently surplus DNA is doing. But from the point of view of the selfish genes themselves, there is no paradox. The true ‘purpose’ of DNA is to survive, no more and no less. The simplest way to explain the surplus DNA is to suppose that it is a parasite, or at best a harmless but useless passenger, hitching a ride in the survival machines created by the other DNA.” (The Selfish Gene, p. 47)

12 Replies to “Junk DNA turns out to influence diabetes risk

  1. 1
    wd400 says:

    Non-coding, not junk. No one who knows what they were talking about has said all non-coding sequences are junk.

  2. 2
    sixthbook says:

    From AP Biology Textbook by Campbell and Reece, 7th Edition page 374:

    “The bulk of most eukaryotic genomes consists of noncoding DNA sequences, often described in the past as ‘junk DNA'”

  3. 3
    wd400 says:

    There are certainly a lot of people who don’t know what they are talking about.

  4. 4
    Querius says:

    There certainly is! Why just look at what the idiots at Medical News wrote:

    Junk DNA – What is Junk DNA?
    In genetics, “junk DNA” or noncoding DNA describes components of an organism’s DNA sequences that do not encode for protein sequences.

    In many eukaryotes, a large percentage of an organism’s total genome size is noncoding DNA, although the amount of noncoding DNA, and the proportion of coding versus noncoding DNA varies greatly between species.

    Much of this DNA has no known biological function. However, many types of noncoding DNA sequences do have known biological functions, including the transcriptional and translational regulation of protein-coding sequences.

    (snip)

    Junk DNA Term
    Junk DNA, a term that was introduced in 1972 by Susumu Ohno, is a provisional label for the portions of a genome sequence of a for which no discernible function has been identified.

    According to a 1980 review in ”Nature” by Leslie Orgel and Francis Crick, junk DNA has “little specificity and conveys little or no selective advantage to the organism”.

    The term is currently, however, a somewhat outdated concept, being used mainly in popular science and in a colloquial way in scientific publications, and may have slowed research into the biological functions of noncoding DNA.

    Emphasis added by Querius

    See http://www.news-medical.net/he.....k-DNA.aspx

    Also, Nature magazine . . .

    http://www.nature.com/scitable.....k-dna-1211

    Appalling, isn’t it!

    This kind of stuff is all over the internet and various scientific journals. Apparently, only wd400 is properly informed. 😉

    -Q

  5. 5
    RexTugwell says:

    There are certainly a lot of people who don’t know what they are talking about.

    Agreed

  6. 6
    CuriousCat says:

    I may be totally wrong, but I get the impression that Darwinists are slowly (in an evolutionary way :)) changing the “junk DNA” phrase to “non-coding DNA”, so that the recent experimental falsification to the junk-DNA hypothesis can be bypassed. In a way, this is logically plausible. Since Darwinian evolution has so little predictive power (hence very little testability), it does not strictly suggest we HAVE to find nonfunctional (=junk) DNA in genome, so finding functions to non-coding genes do not falsify Darwinism. On the other hand, the existence of non-coding DNA has been equated to non-functional DNA and used as an argument to corroborate Darwinism against teleogical argument, as seen here (note that the word USELESS shows that here noncoding-DNA = junk-DNA):

    The simplest way to explain the surplus DNA is to suppose that it is a parasite, or at best a harmless but USELESS passenger, hitching a ride in the survival machines created by the other DNA.

    Overall, I agree that junk DNA -> non-functional DNA conversion saves the Darwinian hypothesis from falsification, but makes it lose one its most important verificational observations, particulary used against the design argument.

  7. 7
    doncarlo says:

    Are the following true?

    http://sandwalk.blogspot.ca/20.....-want.html

    Here are five things you should know if you want to engage in a legitimate scientific discussion about the amount of junk DNA in a genome.
    Genetic Load
    1.Every newborn human baby has about 100 mutations not found in either parent. If most of our genome contained functional sequence information, then this would be an intolerable genetic load. Only a small percentage of our genome can contain important sequence information suggesting strongly that most of our genome is junk.
    2.C-Value Paradox
    A comparison of genomes from closely related species shows that genome size can vary by a factor of ten or more. The only reasonable explanation is that most of the DNA in the larger genomes is junk.
    3.Modern Evolutionary Theory
    Nothing in biology makes sense except in the light of population genetics. The modern understanding of evolution is perfectly consistent with the presence of large amounts of junk DNA in a genome.
    4.Pseudogenes and broken genes are junk
    More than half of our genomes consists of pseudogenes, including broken transposons and bits and pieces of transposons. A few may have secondarily acquired a function but, to a first approximation, broken genes are junk.
    5.Most of the genome is not conserved
    Most of the DNA sequences in large genomes is not conserved. These sequences diverge at a rate consistent with fixation of neutral alleles by random genetic drift. This strongly suggests that it does not have a function although one can’t rule out some unknown function that doesn’t depend on sequence.
    If you want to argue against junk DNA then you need to refute or rationalize all five of these observations.

  8. 8
    Querius says:

    How can Dr. Moran be so certain that what he doesn’t understand must therefore be “junk”?

    How is his argument any different than that regarding “vestigial organs” (evolutionary vestiges) from a hundred years ago?

    A few may have secondarily acquired a function but, to a first approximation, broken genes are junk.

    The cracks in Dr. Moran’s dogmatic position are beginning to show.

    -Q

  9. 9
    TSErik says:

    How can Dr. Moran be so certain that what he doesn’t understand must therefore be “junk”?

    Hooray for the “argument from ignorance” fallacy. But surely no Darwinist would employ that. No.

  10. 10
    Querius says:

    An “argument from ignorance” fallacy would conclude either

    A. One can’t be certain that DNA is junk, therefore it must not be junk.

    B. One can’t be certain that DNA is not junk, therefore it must be junk.

    If anything, Dr. Moran’s position aligns itself with B.

    My question in #8 is how can Dr. Moran be so certain. It would seem to me that Dr. Moran cannot logically conclude that what he calls junk is truly junk. It might be junk for all I know, but ignorance of this DNA does not warrant any other conclusion than “we don’t know what it does yet.”

    -Q

  11. 11
    TSErik says:

    If anything, Dr. Moran’s position aligns itself with B.

    Certainly. I was agreeing with you Q, not accusing you of the fallacy. 🙂

  12. 12
    Querius says:

    Just making sure! 😉

    -Q

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