What evidence suggests that life was common on Earth within a billion years of its formation?
A)Life must have formed early in order to produce the variety of lifeforms seen today.
B)rocks older than 3.85 billion years with the carbon- 12 to carbon- 13 ratio typical of living organisms
C)3)5 billion year old rock structures formed by microbes called stromatolites
D)A and C
E)B and C

Question

Quizplus · Accepted Answer

Option E provides two pieces of evidence to support the idea that life was common on Earth within a billion years of its formation. The presence of 3.5 billion-year-old stromatolites, which are structures formed by microbes, indicates that life was already present and thriving at that time. Additionally, the discovery of rocks with a carbon-12 to carbon-13 ratio typical of living organisms that are older than 3.85 billion years suggests that life had already evolved and was using carbon as a building block. The fact that life must have formed early on to produce the diversity of lifeforms we see today supports the concept that life was common on Earth within a billion years of its formation.

What Evidence Suggests That Life Was Common on Earth Within