Stromatolite fossils that formed 3.5 billion years ago indicate that

Stromatolite fossils are the oldest known fossils, that formed 3.5 billion years ago when the environments of Earth were too hostile to support life as we know it today. They are layered mounds, columns, and sheet-like sedimentary rocks
Stromatolite fossils  indicate that  life must have arisen quite a bit earlier, perhaps 3.9 billion years ago.

I’m not exactly sure what your trying to ask, but if it’s how an organelle is similar to a body system or a part a nucleus is like a in function. but i don’t fully understand what you’re trying to ask