A MEETING WITH THE UNIVERSE
Amino acids have been synthesized
non-biologically under conditions that
simulate those postulated for the
primitive Earth, followed by the synthesis
of most of the biologically im
A laboratory model was developed
for the evolution of cell structure
from nonbiological precursors.
Ammonia and water molecules were
detected in interstellar space with
radio telescopes, followed by the
discovery of many more important
organic molecules and precursors.
Amino acids and other biologically
significant organic substances have
been found to occur indigenously in
meteorites and to be of nonbiogenic
Analysis of rock and soil samples returned
from the Moon provided no
evidence for past or present life and
only traces of the precursors of amino
Simulations of the atmospheric chem
istry of the outer planets showed that
these atmospheres may be sites where
extensive abiotic synthesis of organic
molecules is presently occurring.
Spectroscopic observation of comets
has revealed the presence of biolog
ically important ions, molecules, and
Viking lander experiments found no
existing life or organic chemicals in
the soil at two locations on Mars.
The Martian soil was found to possess
intriguing chemical properties that
mimic, in some respects, certain reactions
of biological systems.
A third kingdom of microorganisms,
the Archaebacteria, was shown to be
distinct from the prokaryotes and
eukaryotes, thus altering concepts of
the earliest lines of descent of species
on the Earth.
Clay minerals were found to markedly
influence the rate and direction of
chemical evolution processes.
Algae, bacteria, and fungi were discovered
living inside rocks from the
coldest and driest deserts of the Antarctic,
which represent the closest
terrestrial analog to the environment
Microfossils were discovered in rocks
3.5 billion years old, a finding that
pushed back the estimate of the time
when life originated on the Earth to
within the first billion years after the
Earth was formed.
Nucleic acid polymers in the biologica
size range were synthesized in a non-random
manner, under geologically