Given a scientific passage and an answer, generate a question for the given answer.
One example: Passage: A frameshift mutation is a deletion or insertion of one or more nucleotides that changes the reading frame of the base sequence. Deletions remove nucleotides, and insertions add nucleotides. Consider the following sequence of bases in RNA:. Answer: nucleotides.
Solution is here: A frameshift mutation is a deletion or insertion of one or more of what that changes the reading frame of the base sequence?
Explanation: The science passage defines frame mutation and the main compoment here is nucleotides. Hence the generated question is apt.

Now, solve this: Passage: For the first 4 billion years of Earth history there is only a little evidence of life. Organisms were tiny and soft and did not fossilize well. But scientists use a variety of ways to figure out what this early life was like. Note that the period from Earth's origin to the beginning of the Phanerozoic is called the Precambrian. Answer: precambrian
Solution:
What is the period from earth's origin to the beginning of the phanerozoic eon?