Sunday, October 27, 2013

Trace Dominguez of Discovery News Says 98% of Your Genome Is Junk

Theme Genomes & Junk DNAI happened to stumble on this video where Trace Dominguez (@trace501) promotes the idea of junk DNA based on the C-value Paradox—a version of the Onion Test. It's good that he tells the general public about junk DNA but it's bad that he equates "noncoding DNA" with "junk DNA." It's really silly to tell people that the only important part of your genome is the 2% that codes for proteins.

Just so you know, some of the important known functions of "noncoding DNA" are [What's in Your Genome?] ....
  1. Genes for functional RNAs like ribosomal RNA, tRNA, and a host of others.
  2. Regulatory sequences that control expression of all genes.
  3. Part of intron sequences.
  4. Origins of replication;specific sites where DNA replication begins.
  5. Telomeres.
  6. Centromeres.
  7. SARS or scaffold attachment regions; sites required to organize chromatin.
  8. Functional transposons or "selfish DNA."
  9. Functional DNA and RNA viruses.
Scientists believe that about 2% of our genome encodes proteins and about 8% has other functions. It is not true that all noncoding DNA is junk. No knowledgeable scientist ever said that.

I realize that the kind of presentation shown in this video doesn't lend itself to a detailed description of noncoding DNA functions but surely we can do better than this? Why not say that scientists have determined that genes make up about 2% of our genome and about 8% contains information necessary for the proper functioning of genes and chromosomes? The rest, about 90%, is thought to be junk?

98% of your DNA is junk


6 comments :

  1. No knowledgeable scientist ever said that.

    I think that some knowledgeable scientists equivocated junk DNA with non-coding DNA. Though I have to say, those scientists adopted a slightly different definition of junk DNA than the one commonly adopt here (that of total non-function, in terms of its information content). I read T. Ryan Gregory's survey of the early literature on junk DNA, and it seems that Comings (1972) was the first to apply the term to all non-coding DNA.

    It seems that the term and its usage did change over time (as you acknowledged in the previous thread), and this may have created some confusion within and outside the scientific community.

    ReplyDelete
    Replies
    1. I'm sorry, but any scientist back in 1972 who was unaware of ...

      1. genes for functional RNAs (e.g. ribosomal RNA and tRNA) = noncoding genes
      2. regulatory DNA sequences where repressors and activators bind, and
      3. origins of DNA replication

      was not knowledgeable. No knowledgeable scientist ever said that all noncoding DNA is junk.

      Delete
    2. No ID creationist-- not Luskin and not Jonathan Wells -- has ever produced a quote from a geneticist or molecular biologist saying that he himself believed that non-coding DNA is equal to, or a subset of, Junk DNA. They have quotes from people saying the converse, but they falsely present this as evidence of their thesis.

      Delete
    3. @Diogenes,

      But ... but ... but ... Jonathan Wells writes in "The Myth of Junk DNA" ...

      ... when molecular biologists discovered in the 1970s that most of our DNA does not code for proteins, neo-Darwinians called non-coding DNA "junk" and attributed it to molecular accidents that have accumulated in the course of evolution. (p. 15)

      and

      Although some suggested that non-protein-coding DNA might help to regulate the production of proteins from DNA templates, the dominant view was that non-protein-coding regions had no function. (p. 20)

      Surely you don't mean to imply that Jonathan Wells was (gasp!) lying? :-)

      Delete
  2. Hello Larry, are you aware of the variety of ways in which ID creationists try to explain away junk DNA?

    ReplyDelete
    Replies
    1. Of course. I wrote a large series of posts on Jonathan Wells' book "The Myth of Junk DNA" and I've addressed every claim that the IDiots have ever made. It's a lot like shooting fish in a barrel because the IDiots are ignorant of most of the evidence supporting junk DNA and they have deceived themselves about the history and modern evolutionary theory.

      Why do you ask?

      Delete