system
Given the following post, respond as if you're commenting on Reddit:
human
How do we know for sure that a species is extinct?

What are the criteria that must be met for these conclusions to be made? How do we not know that there aren't more of the species that we just haven't been able to find?
gpt
We don't exactly know, but biologists will be monitoring species that are near extinction and when they stop seeing any specimens/signs of specimens for a long period of time they will declare it extinct. Many examples of them being wrong exist too.