For many years, the human genome was viewed as a book of life in which sections of great eloquence and economy of expression were interspersed with vast stretches of gibberish. The legible sections contained the code for making cell proteins; the other regions, representing about 90% of the entire genome, were dismissed as “junk DNA,” having no discernable purpose.
Research has taught scientists otherwise. Far from being useless filler, many non-coding sections have been shown to play a key role in regulating gene activity — increasing or decreasing it as needed.
