From my reference below: "If most eukaryotic DNA is functional at the organism level, be it for gene regulation, protection against mutations, maintenance of chromosome structure, or any other such role, then why does an onion require five times more of it than a human?"
Of course, one can always say, "How arrogant to think we know everything." But given our current understanding of evolution and genetic function, the specific identity of a genetic sequence correlates with its function. If that function is important, the sequence should be preserved to a degree better than random chance.
To deny this is to suggest that any random sequence of genetic material can serve a vital purpose while being subject to endless mutation without consequence. This raises the question: What do we mean by a "specific sequence" if it isn’t conserved and is constantly mutating?
I assume you are familiar with the information I’ve just shared. I’m curious where we are diverging in our views because it feels like we are not discussing the same thing.
This artcle fairly represents my understanding of what I mean when I say "junk DNA": https://journals.plos.org/plosgenetics/article?id=10.1371/jo...
There's an abysmal number of post-transcriptional effects that are functional. Start with something like [1].
There's also plenty of evidence (like TFA and [2]) of "junk" DNA turning out to be functional through some contrived and completely unexpected mechanisms.
Every time someone says something like "this is how Biology works" one can lmao all the way to the lab.
1: https://en.wikipedia.org/wiki/Epigenetics
2: https://pubmed.ncbi.nlm.nih.gov/36484387/