caffeine writes:
There seems to be a bit of a leap of assumptions here. The claim is that, since this organism is doing just fine without all that non-coding DNA, it must not, therefore, serve any purpose in that organism. The conclusion doesn't really seem justified.
What might help test the theory that "junk" DNA doesn't do anything is to see if it usually corresponds to regions of rapid evolution, indicating an area not subject to selection. By "rapid evolution" I mean that the rate of change is roughly equal to the rate of copying errors. What they call the molecular clock should run at a much faster rate in non-functional regions.
Of course, if its function is to act as spacers this won't help, but at least theoretically this, too, is possible to study, say, by somehow excising "junk" DNA regions and studying the effects.
--Percy
™ Version 4.2
