ASBOG Practice Exam

The supereon before the first macro-life appeared is known as what?

1. Phanerozoic

2. Precambrian

3. Hadean

4. Proterozoic

The correct answer is: Precambrian

The period known as the Precambrian represents a vast span of time in Earth's history, specifically before the abundant fossil evidence of macro-life became visible. This time frame encompasses three major divisions: the Hadean, Archaean, and Proterozoic eons. It is significant for setting the stage for the development of life, with conditions evolving to support more complex organisms. During the Precambrian era, the Earth saw the formation of its initial crust, the emergence of simple life forms such as bacteria and algae, and critical atmospheric changes, like the Great Oxidation Event, which eventually paved the way for the proliferation of more complex life forms in the subsequent Phanerozoic eon. Therefore, identifying the Precambrian is correct as it encapsulates the time before the advent of macro-life, making it a fundamental period in geological and biological history.