Nassim Taleb on on survival of the least fit and their vulnerability to the rare event

Recall that someone with only casual knowledge about the problem of randomness would believe that an animal is at the maximum fitness for the conditions of its time. This is not what evolution means; on average, animals will be fit, but not every single one of them, and not at all times. Just as an animal could have survived because its sample path was lucky, the "best" operators in a given business can come from a subset of operators who survived because of over-fitness to a sample path - a sample path that was free of the evolutionary rare event. One vicious attribute is that the longer these animals can go without encountering the rare event, the more vulnerable they will be to it.

~ Nassim Taleb, Fooled by Randomness, 2nd Edition, p. 92