Match each academic argument with the implicit unstated assumption on which its conclusion necessarily depends.
- Computational Linguist: Reconstructions of Proto-Vasconic preserve shared lexicon for animal husbandry but lack cognates for cereal cultivation. Because ancestral vocabularies reliably capture core subsistence activities, speakers of Proto-Vasconic must have subsisted without practicing agriculture.The absence of shared agricultural cognates among descendant languages is not solely the result of post-divergence vocabulary attrition across all surviving lineages.
- Paleoseismologist: Stalagmites in the Mendip cavern network exhibit sudden axis-of-growth shifts dated to approximately 4,200 years ago. Since severe ground motion fractures speleothem bases and alters their orientation, a major regional earthquake must have occurred at that time.The structural realignments of the stalagmites were not produced by non-seismic geomechanical processes, such as localized cavern floor compaction or sediment washout.
- Planetary Scientist: Infrared imaging of Enceladus shows sharp thermal anomalies concentrated along surface fractures. Because cyclic tidal stress generates frictional heating along crustal shear zones, endogenous tidal friction, rather than the crystallization of subsurface water pockets, is the principal heat source powering the cryovolcanic plumes.The observed concentration of thermal anomalies along surface fractures is not primarily an artifact of latent heat escaping from freezing subsurface liquid bodies.
Answer
The argument regarding Proto-Vasconic vocabulary pairs with the assumption that missing cognates are not due to universal daughter-language attrition; the argument regarding cavern stalagmites pairs with the assumption that non-seismic floor shifts did not cause the realignments; the argument regarding Enceladus thermal anomalies pairs with the assumption that fracture heat is not an artifact of latent heat release from subsurface freezing.
Each correctly paired assumption functions as an essential defender. For the linguistic argument, assuming that agricultural terms were not universally lost across all daughter languages is mandatory to conclude that the ancestral speakers lacked agriculture. For the paleoseismological argument, ruling out non-seismic cavern settling is mandatory to infer an earthquake. For the planetary science argument, establishing that fracture heat is not merely vented latent heat is mandatory to conclude tidal friction is the primary heat engine.
Step-by-Step Solution
Key Concept
Application of the Negation Test to identify Defender assumptions that rule out alternative explanations across diverse argument structures.
Estimated Time:2m 30s