Answer:
Cyanobacteria would be the first living thing on earth.
Step-by-step explanation:
This would make sense because bacteria is always lurking somewhere even if it isn't in any organism. Bacteria can live in rocks or sand. So it would make sense that some type of bacteria would be the oldest thing.
Bacteria could be also one of the last living thing on earth as well.
If you have any questions feel free to ask in the comments - Mark
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