phys.org | As the floor plan of the living world, DNA guides the composition of animals ranging from unicellular organisms to humans. DNA not only helps shepherd every organism from birth through death, it also plays an essential role in the development of many human diseases.
But it wasn't always so. Long before DNA emerged as the molecule of life, its closely related cousin, RNA (ribonucleic acid), held center stage.
The RNA world refers to a time in earth's distant past when primitive forms used RNA rather than DNA to archive genetic information, pass it along using RNA-based copying machinery and perform biological reactions.
With the emergence of DNA, RNA came to play an intermediary role, copying DNA messages known as genes and translating them into proteins. This pathway from DNA to RNA to protein has become so engrained in the field of biology it is often referred to as "the central dogma."
Recently, however, RNA's strict subservience to DNA has been called into question. New discoveries have prompted an explosion in RNA research, with vital implications for both the foundations of biology and the practice of medicine. (Sidney Altman, who won the Nobel Prize for establishing that RNA can act independently and perform chemical reactions on its own, providing powerful evidence for the RNA world hypothesis, has recently joined ASU's School of Life Sciences).