Digital RNA regulation of complex organisms

Proteins and their products are the analog components of cells. However the number of protein-coding genes in humans is not markedly different from that of a simple nematode worm, despite the vast differences in their developmental complexity. On the other hand, most of the human genome is transcribed, mainly into non-protein-coding RNAs. Both logic and emerging evidence suggest that these RNAs are not junk, but form an extensive regulatory network that was a necessary adaptation to solve the vastly expanded regulatory requirements of complex organisms, and that these RNAs now comprise a hidden layer of feed-forward control signals that direct the epigenetic trajectories of differentiation and development.