Thursday, November 22, 2012

“Junk” DNA No Longer Junk

More DNA Revealed.
The massive ENCODE project unveiled Sept. 5, 2012 with the simultaneous publication of multiple studies—the effort of hundreds of scientists at 32 institutions from around the world—has unveiled a genome that is much more complex than previously imagined.

Intelligent Attractions.
The area of DNA not coding for proteins previously thought to be “junk,” roughly 98% of the human genome, has now been found to possess over 4 million gene switches which control how and when the 20,000 or so genes that code for proteins are expressed. Until now they have found that 80% of the human genome has at least one function, not the mere 2% previously thought, and they believe they have only scratched the surface. These areas between protein-coding genes are filled with enhancers (DNA that regulates gene expression), promoters (points of initiation of DNA to RNA transcription), and genes that create RNA which then bind to other areas of DNA, even distant ones, to control gene expression.
It is no longer sufficient to examine the genome linearly, in two dimensions, but now a three-dimensional interactive model of the genome needs to form the new paradigm. Complex interactions between distant elements on the genome through three dimensional looping and other mechanisms opens up a whole new mode of thinking about the way the genome works whose principles of function are not yet known.

Better Explanations Required.
As we peel back the layers of the structure and functionality of the human genome, the even-increasing complexity of the system provides further doubt about the adequacy of the classical evolutionary mechanisms of random mutation and natural selection to have produced such a multifaceted and multi-layered system.