I think StringJunky's post above describes it quite well. I'm very happy to see so many people give their input; It is quite refreshing. Non-coding DNA refers to it not coding for a protein product..plain and simple. This doesn't mean, however, that it doesn't have a purpose..IE it may code for an RNA product. While the junk dna is, as described by the patrons above, unfortunately named. Much of what we know as 'junk dna' is actually the result of transposable elements. These transposable elements are most certainly not 'junk' and have had a profound impact on the evolution of both prokaryotic and eukaryotic organisms(please don't crucify me).
