Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Definition of gene needs reveiwing ?

  1. Sep 5, 2012 #1
    According to this news article , genome analysis has shown that the understanding of what constitutes a gene has to reveiwed and redefined in light of new evidence. Btw there is no junk DNA in our genome.


  2. jcsd
  3. Sep 5, 2012 #2
    Re: Definition of gene needs reviewing ?

    At some point soon the entire idea of "genes" will have to be replaced with a more general concept. One sign that it is close to the end is that we can't precisely count genes in a genome. Small variations in the definition of a gene result in large differences between number of genes in the genome.
    The number of genes in the human genome have varied between 10^4 to 10^6. Right now, the number seems to have settled down to 3×10^4. However, the definition chosen for this number is somewhat arbitrary.
    One thing that complicates the definition of gene is that some contiguous sequences of RNA are transcripted from discontiguous segments of DNA in the chromosome. Another thing that complicates the definition of gene is that in eukaryotes, proteins are often synthesized in a two or three step process after the genes are translated into proteins. So enzymes do not always have one on one mapping to the corresponding sequence of DNA.
    Developmental biology still has a revolution or two in its future. Although a "review" of the definition of gene would be helpful, there is no way to fix the concept of gene. I suspect that the theory of gene networks may be due for some breakthroughs. Furthermore, we have to find out more about epigenetic inheritance. By epigenetics, I mean inheritance through molecules other than DNA.
    Don't get me wrong. The "gene centric" models of developmental biology will still continue to help evolutionary biology for a considerable amount of time in the future. Even while a new "synthesis" of biology is being developed, the gene centric approximation will be extremely useful for simplifying and clarifying evolution. However, there are some fundamental inconsistencies in the theory of genetic inheritance as we know it today.
    I predict that in the future, "the gene" will have the same level of acceptance in biology as "the fluid element" has in classical mechanics. "The gene" will be recognized as a mathematical concept based on an approximation rather than a strictly physical concept based on the general theory.
  4. Sep 6, 2012 #3


    User Avatar
    Gold Member

    I think (hope) that it will soon be a time for dynamical systems to play role in these definitions. There's a framework paper out in Biosystems called Mathematical modelling in the post-genome era: understanding genome expression and regulation— a system theoretic approach:

    BioSystems 65 (2002) 1–18
    © 2002 Elsevier Science Ireland Ltd. All rights reserved.
  5. Sep 6, 2012 #4


    User Avatar
    Gold Member

    Also, so that dynamical system's enthusiasts don't get too carried away, a caveat from the introduction:

Share this great discussion with others via Reddit, Google+, Twitter, or Facebook