Life is Sweet
A controversial
theory that sugar-related molecules may
have seeded life on earth has been boosted
by GC-mass spectrometry studies of
meteorites. This space rock arrived on the
infant earth around four billion years ago
leading to the growth of bacteria that
evolved into primitive life forms.
So-called
polyhydroxylated compounds (polyols) have
been found in carbon-rich asteroid
fragments discovered last century in
Australia and the United States, by a team
from NASA's Ames Research Center. It is
concluded that polyols were present on the
early earth and therefore, at least
available for incorporation into the first
forms of life.
The idea of life's
ingredients arriving on meteorites gained
ground among space scientists after they
were found to contain amino acids, the
basics of proteins. Additional experiments
showed that these acids could be
chemically produced in the laboratory by
combining methane and ammonia.
The polyols are a
family of carbon compounds that comprise
sugar, sugar alcohols and sugar acids.
Polyols provide the "skeleton" for many
other molecules as well as a vital energy
source for cells.
The study's samples
came from the Murchison meteorite, found
near Melbourne, Australia in 1969, and the
Murray meteorite located around 1930 on a
farm in Oklahoma. Gas chromatography-mass
spectrometry (GC-MS) was used to ionise
and identity the polyols.
The study appears in
Nature (December 2001) Volume 414, 879 -
883.