Which life form has been present on Earth the longest?
A)jawed vertebrates
B)humans
C)microbes such as bacteria
D)single-celled eukaryotes such as protists

Question

Quizplus · Accepted Answer

Microbes such as bacteria have been present on Earth for approximately 3.5 billion years, making them the life form that has been present on Earth the longest. Jawed vertebrates, such as fish and reptiles, have been present for approximately 450 million years, while humans have been present for only about 200,000 years. Single-celled eukaryotes, such as protists, have been present for about 2 billion years, which is still less than the time period of bacteria.

Which Life Form Has Been Present on Earth the Longest