hard · GRE Verbal

Passage: The discovery of soft tissue in fossilized dinosaur bone was initially dismissed as contamination, and the reflex was reasonable: proteins were thought to degrade within, at most, a million years, and the specimens were tens of millions of years old. What the skeptics underestimated was not the chemistry of decay but the range of conditions under which it operates. Subsequent work showed that iron liberated from the animal's own hemoglobin can cross-link and stabilize proteins, acting rather as formaldehyde does in a laboratory. The original objection was thus not so much wrong as parochial: it generalized from decay rates observed under ordinary conditions to a universal ceiling that the fossil record did not, in fact, respect. The function of the final sentence is to:

1. Concede outright that the skeptics' underlying chemical reasoning about protein decay was fundamentally mistaken
2. Characterize the flaw in the original objection as one of overgeneralization rather than of chemical error
3. Propose iron cross-linking as the sole mechanism by which any soft tissue can survive fossilization
4. Restate the skeptics' contamination position in order to defend it robustly against the new chemical evidence
5. Question anew whether the fossilized soft tissue was ever correctly identified as tissue in the first place

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