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).
