craproot
Explanation
The Joke
A caveman-era father tells his family about a plant growing on their land. He explains that the bulb is bitter, but they must not eat the leaves, because they will go hungry and sick when winter comes if they do. In other words, the root vegetable is unpleasant but sustaining, while the appealing-looking leaves are nutritionally worthless or harmful. The scene then jumps forward "three generations later" to a modern person at a restaurant indignantly declaring that "this carrot is completely unauthentic" -- presumably complaining about a perfectly good, farm-fresh carrot because it does not match some idealized notion of artisanal cuisine.
The comic contrasts humanity's long, brutal history of subsistence agriculture -- where food was scarce, unpleasant, and the difference between eating the right and wrong parts of a plant could mean starvation -- with modern food snobbery, where people with abundant food choices complain about "authenticity." The ancestors who struggled to survive on bitter roots would be baffled by descendants who reject perfectly edible food because it does not meet aesthetic standards.
The Humor
The joke is a sharp commentary on food culture pretentiousness. The juxtaposition between desperate survival farming and casual restaurant criticism creates an absurd contrast. The caveman's earnest, life-or-death instructions about which parts of a plant to eat are placed directly against a modern diner's frivolous complaint about authenticity. The word "unauthentic" is especially funny because the caveman's version of the food -- bitter, difficult, and eaten out of pure necessity -- is the truly "authentic" experience, and no modern foodie would actually want it. The comic suggests that our obsession with "authentic" food is itself deeply inauthentic.