Geoscience Reference
In-Depth Information
CHAPter 6
The Early History of Atmospheric Oxygen:
Biological Evidence
The twelfth-century French philosopher Bernard of Chartres is quoted
as saying:
We are like dwarfs on the shoulders of giants, so that we can see
more than they, and things at a greater distance, not by virtue of
any sharpness of sight on our part, or any physical distinction, but
because we are carried high and raised up their giant size
.
1
This sentiment has endured the centuries, and is as true today as it was
900 years ago. In this chapter we begin our discussion of the history
of atmospheric oxygen through geologic time (see
ig. P.1
for the geo-
logic time scale), and one of the giants in this discussion is Vladimir
Vernadsky, the Ukranian mineralogist turned geochemist and visionary
thinker. Vernadsky was born in 1863 and died in 1945. He therefore
lived through incredible turmoil, including two world wars and the fall
of czarist Russia. In 1926 he published his magnum opus
he Biosphere
,
in which he systemically explored how life works as a geological force.
In this volume, his observations were keen, his reflections were deep,
and his pronouncements were grand. One subject he touched upon was
the history of atmospheric oxygen. He initiated this discussion by stat-
ing the following:
