The first living cells may have evolved around how long ago?
2.2 billion years
900,000 years
6 billion years
4 billion years
The Precambrian Supereon (4.6 billion–544 million years ago) is the first major division of the geologic time scale. The first living cells may have evolved around 4 billion years ago. By 1 million years ago, the first multicellular eukaryotes had evolved. The Precambrian ended with the first of six mass extinctions that occurred during Earth’s history.