Answers:
1. Imagine the entire history of Earth as a single calendar year. By March 3, the first
evidence of ___________________ is found.
C: single-celled bacteria
2. Ediacaran fauna, the first multicellular organism, came along on:
D: November 11
3. What is the "Cambrian Explosion of Life"?
B: When all modern phyla started to appear
4. If we compare geologic time to your life from when you were born to when you
started high school . . .
B: 12 years old
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4 Geologic Time Scale Answer Key
