How many times have humans been pushed to the brink of extinction?

Question

I know that on several different occasions in our history, humans have been pushed to the brink of extinction, at one point the numbers may have been as low as a couple thousand.

How many different times in our history have we almost been extinct and what were the causes?

Answer 1

Approximately seven.

Answer 2

theres no such thing, the bubionic plague was prety big, but still...theres never been only a few thousand people (unless you beieve in Judaism, Islam, or christianity then you believe that Noah and his family were one of the only people alive)