The eye of the Sahara is most probably a geologic dome, entirely earth-made, and it appeared before there was
any life on earth. Its contemporary appearance is due to erosion.
https://geologyscience.com/gallery/e...hat-structure/
Which does not mean that some exterior impact event could not wipe out the better part of life on earth anytime, as well as some supervolcano could, from the Phlegraean Fields to Yellowstone.
Or a nuclear war, or a biological one, or a plague. We have a lot to choose from
