“Scientists rightly resist invoking the supernatural in scientific explanations for fear of committing a god-of-the-gaps fallacy (the fallacy of using God as a stop-gap for ignorance). Yet without some restriction on the use of chance, scientists are in danger of committing a logically equivalent fallacy-one we may call the “chance-of-the-gaps fallacy.” Chance, like God, can become a stop-gap for ignorance.”