Passage Summary: Scientists tested whether sea butterflies stay safe because of their taste by putting their chemicals into fish food. Since the fish ate the chemical-flavored food anyway, the scientists decided the chemicals don't help the butterflies avoid predators.

Conclusion: The chemical compounds produced by sea butterflies are not the reason they avoid being eaten.

Reasoning: When individual chemicals were added to food pellets, predators still consumed them, suggesting the chemicals do not act as a deterrent.

Analysis: The ecologist's argument suffers from a classic composition error. They assume that because individual chemical compounds failed to deter predators, the compounds collectively—or in their natural concentration—must also be ineffective. In the world of biology, the whole is often greater than the sum of its parts. Look for an answer choice that points out the possibility that these chemicals might only work when combined or when presented in a different way than a single-compound pellet.