How did life begin?
Answers
At the time it was widely agreed that stromatolites were oldest known lifeform on Earth which had left a record of its existence. Therefore, if life originated on Earth, this happened sometime between 4.4 billion years ago, when water vapor first liquefied, and 3.5 billion years ago.
the origin of life is considered as a unique event in history of universe
Explanation:
many theories have been proposed to explain origin of life. most of them are of historical importance.
A)THEORY OF SPECIAL CREATION
it is purely a mythological belief that states that all living organisms are created by god,(a divine power) in 6 days which is also written in bible.
B)COSMOZOIC THEORY or PANSPERMIA:
It says that life existed all over universe (cosmos) in the form of resistant spores.early Greek thinkers like Aristotle, etc. believed that these spores were transferred to different planets including earth.It is a concept favourable to astronomers.