by Jack Le Moine
For 4 billion years, the most advanced form of life on Earth was single celled organisms. From the standpoint of life, this seems like a boring period but the planet was undergoing massive changes. The outer crust was settling; the atmosphere was forming; meteors (maybe even whole planets) crashed down from the sky. Mountains formed. Weather changed.
The greatest ice age in the planet’s history occured. Ice and snow covered the entire planet. Then the climate warmed.
And God said, Let the waters bring forth abundantly the moving creature that hath life.
MYA = Million Years Ago
BYA = Billion Years Ago
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