Good Things Come In Small
Packages
During the next 1.96 billion
years, known as the Proterozoic Eon (42.6 yards long on the "100 Yard
Model"), several major milestones come to pass:
The Earth cools enough for the
water vapor in the atmosphere to condense into liquid and solid forms.
The oceans are formed.
The hydrologic (water) cycle
begins. This starts the weathering and erosion of
landforms.
This is very important for wearing down mountain ranges and
depositing
layers of sediments that will form sedimentary rocks.
The first life forms develop in
the primordial oceans. These would consist only of single celled
organisms until the very end of the Precambrian Period when
multicellular life appears.
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Cellular Life |
The first life forms on Earth were most likely single celled organisms.
Image
credit:
Wilhelm Foissner, Institute of Zoology, University of Salzburg for the
Bureau of Land Management, U.S. Dept. of the Interior
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