However, scientists believe that the earliest life forms were single-celled organisms called prokaryotes. These organisms were likely thermophiles - meaning they thrived in extremely hot environments like volcanic vents.
Here's why we believe this:
* Early Earth was very different: The early Earth was extremely hot, with a very different atmosphere than today.
* Fossil evidence: The oldest fossils we have found are of single-celled organisms from about 3.5 billion years ago.
* Genetics: The genetic similarities between all living organisms suggest a common ancestor that was likely a prokaryote.
It's worth noting that there are many different theories about how life first arose on Earth, and the specific details of the first organism are still a mystery!
