Passage Summary: Just because we now know that ancient food rules were healthy or helpful doesn't mean that's why the ancients made them, because they didn't have our modern science to figure that out.

Conclusion: Modern data regarding the functions of ancient food prohibitions cannot explain why those prohibitions were originally created.

Reasoning: The ancient people who established these rules did not have access to the scientific and anthropological data that modern researchers use to identify the rules' benefits.

Analysis: The author assumes that in order for a benefit to explain the *origin* of a practice, the people starting that practice must have been aware of that benefit. This is the 'Gap.' To find the necessary assumption, we need a statement that links the reason for a rule's creation to the conscious knowledge of its creators. If it were possible for a rule to be created for a reason that the creators didn't fully understand scientifically, the author's argument would fall apart. Therefore, the argument requires the belief that conscious knowledge is a prerequisite for functional origins.