Exploding the Darwin-Friendly Myth of Junk DNA
This just in from Nature magazine, of all places.
Not that long ago, biology was considered by many to be a simple science, a pursuit of expedition, observation and experimentation.Also not that long ago, junk DNA was being defended as an important element of the Darwinian evolution paradigm.
Just one decade of post-genome biology has exploded that view. Biology's new glimpse at a universe of non-coding DNA -- what used to be called 'junk' DNA -- has been fascinating and befuddling. Researchers from an international collaborative project called the Encyclopedia of DNA Elements (ENCODE) showed that in a selected portion of the genome containing just a few per cent of protein-coding sequence, between 74% and 93% of DNA was transcribed into RNA2. Much non-coding DNA has a regulatory role; small RNAs of different varieties seem to control gene expression at the level of both DNA and RNA transcripts in ways that are still only beginning to become clear. "Just the sheer existence of these exotic regulators suggests that our understanding about the most basic things -- such as how a cell turns on and off -- is incredibly naive," says Joshua Plotkin, a mathematical biologist at the University of Pennsylvania in Philadelphia.The question now seems to be whether Ayala, Dawkins, Collins, Falk and other junk DNA proponents will continue to defend junk DNA, whatever they call it?