How are lncDNA/RNA and Neutral Theory Compatible?
|May 13, 2014||Posted by PaV under 'Junk DNA', Evolution, Intelligent Design|
There are many “Neutral Theorists” who maintain that there is a lot of “junk-DNA,” among which long, non-coding DNA=lncDNA is some of the “junkiest.”
But now consider this from Wikipedia:
Nevertheless, despite low conservation of long ncRNAs in general, it should be noted that many long ncRNAs still contain strongly conserved elements. For example, 19% of highly conserved phastCons elements occur in known introns, and another 32% in unannotated regions (Siepel 2005). Furthermore, a representative set of human long ncRNAs exhibit small, yet significant, reductions in substitution and insertion/deletion rates indicative of purifying selection that conserve the integrity of the transcript at the levels of sequence, promoter and splicing (Ponjavic 2007).
If lncDNA is ‘junk’, then according to ‘neutral theory’ it shouldn’t be conserved, not even any portion of it. Yet, of the “highly conserved phastCons elements,” 32% appear in unannotated regions. And 19% of the phastCons elements are found in “introns,” yet we’re told that ‘introns’ are just “junk.” How can neutral theorists, then, maintain their position that most mutations come from molecular evolution (neutral drift), work under the assumption that “highly conserved” portions of the genome are under purifying selection, and then tell us that lncDNA is “junk”? If it is “junk,” then why aren’t ‘neutral mutations’ found across their entire length?
Just being curious.