Passage Summary: Archaeologists found evidence that Neanderthals burned smoky plants like grass and lichen, leading them to believe these ancient humans were smoking meat to keep it from spoiling.

Conclusion: Neanderthals likely used smoke as a method for preserving meat.

Reasoning: Fireplaces used by Neanderthals contained remains of lichen and grass, materials that produce significant smoke but very little heat or light.

Analysis: To weaken this argument, we need to find an alternative reason why Neanderthals would intentionally create a smoky, low-heat fire. The archaeologist assumes that smoke equals meat preservation, but smoke has many other uses. Look for an answer that suggests these fires were used for something else, such as repelling insects, signaling, or perhaps that lichen was simply the only fuel available in that environment. Any evidence that breaks the exclusive link between 'smoky fuel' and 'meat preservation' will do the trick.