Conversely, if there is no selective pressure on this not too harmful DNA, which by the way we're told constitutes most of your DNA, then why wouldn't ‘old’ pseudogenes be scrambled beyond recognition as a result of accumulated random mutations?
Cordially,
Gee, thanks, I think I have this chemistry stuff down.
the L-GLO pseudogene energy component is just a tiny fraction of all the alleged "filler" DNA. So when the total amount of superfluous short DNA sequences become comparable to or greater than that of useful DNA, why wouldn't the selective disadvantage be significant?
If 1000 base pairs requires 1.25 micrograms per day, maintaining the entire genome, 3 billion base pairs, including all the functional bits, all the parasitic sequences, and all the junk, requires 3.75 grams of glucose per day. In other words, having a mechanism for deleting junk sequences might represent the difference of a few tic tacs per day in food consumption. The cost would be the occasional accidental deletion of functional DNA, which would kill or maim the organism.
But why didn't you do that calculation yourself?
Interestingly, the largest known genome is about 90 billion base pairs. That's in a plant, the trumpet lily, but it's interesting that it would correspond to a human needing about 100 more grams of glucose a day, which is a point at which point you might have real selective pressure. So it does seem that genomes have attained a size where their maintenance costs remain a small fraction of the total metabolic needs of the organism. And that's exactly what evolution would predict. Genetic material will tend to expand until selective pressure caused by the metabolic costs starts limiting the size.
Interestingly, the least junky genome appears to be Prochlorococcus marinus, which lives in regions of the ocean where nitrogen and phosphorus, major components of DNA, are in almost undetectably low concentration. So, indeed, where there is real selective pressure to limit junk DNA, junk DNA tends to be limited. And where there is not, it isn't.
Conversely, if there is no selective pressure on this not too harmful DNA, which by the way we're told constitutes most of your DNA, then why wouldn't ‘old’ pseudogenes be scrambled beyond recognition as a result of accumulated random mutations?
And the L-GLO pseudogene indeed is heavily scrambled; it's far further from the mouse gene than you'd expect.
So given that all of your objections seem to have been resolved, I take it you're convinced that in fact L-GLO is an excellent argument for the common ancestry of the mammals?