Southack is correct to the extent that selection favors "trimming" unused junk from the genome in the very rare cases where the tiny amount of extra energy required to copy "junk" DNA (relative to the far larger ordinary metabolic demands of an organism) becomes a "make or break" issue for a given organism -- and it seldom is. However, AntiGuv and furball4paws are correct in that the amount of selection would in actuality be *very* slight, and that ordinarily evolution would not be expected to seriously "prune" genomes, except in the very rare cases where the tiny amount of extra energy required to copy "junk" DNA (relative to the far larger ordinary metabolic demands of an organism) becomes a "make or break" issue for a given organism -- and it seldom is.
That should connect all the dots for you. If Ichneumon believes I have misrepresented his statement, then he's welcome to correct me for my uppityness. ;)
Thanks. That's fine. It's nice to not be hammered for spreading a falsehood...especially when I didn't spread one, so thanks for the correction.
Now, with that out of the way, if there is such miniscule evolutionary pressure to trim out junk DNA code, and if there are so many ways for junk DNA code to be introduced, should we see a predictable *pattern* in the accumulation, in the same species, over time, of junk DNA code?
LOL -- no, you've done a good job of stating it succinctly.