It would take at least 500 survivors to repopulate the earth (without creating major issues because of inbreeding) after an apocalypse.
CDC has an actual “Zombie Plan” in place. It was started as a joke campaign, but actually evolved into real training and countermeasures because “if you’re well equipped to deal with a zombie apocalypse you will be prepared for a hurricane, pandemic, earthquake, or terrorist attack.”
The world was ending in 1806 because someone wrote “Christ is coming” on eggs and stuffed them back into the hen.
There is currently a community of people living on top of a mountain in France. They believe that on December 21, aliens will emerge from the mountain to save them from the apocalypse.