Each passage below presents an academic argument that depends on an unstated foundational premise. Match each numbered argument with the implicit assumption on which its conclusion strictly depends.
- Archaeogeneticist: DNA extracted from Bronze Age human remains reveals ancestral strains of the bacterium Yersinia pestis that lacked the ymt gene, which enables flea-borne vector transmission. Because flea-borne transmission is necessary for the rapid transmission rates characteristic of historical bubonic pandemics, these prehistoric bacterial strains could not have caused widespread outbreaks across dispersed geographic settlements.Human migration and direct physical contact in the Bronze Age were insufficient on their own to propagate Yersinia pestis infections between distant population centers at epidemic scales.
- Financial Econometrician: High-frequency algorithmic trading firms deploy line-of-sight microwave relay networks between electronic exchanges because microwaves propagate roughly 30 percent faster through air than laser pulses do through fiber-optic lines. Consequently, algorithmic firms that rely exclusively on fiber-optic cables will be completely unable to execute profitable statistical arbitrage orders.Profitable statistical arbitrage strategies cannot be sustained on execution horizons long enough to render sub-millisecond telecommunication latency advantages inconsequential.
- Atmospheric Chemist: Proposed solar geoengineering programs plan to inject sulfur dioxide into the stratosphere to reflect solar radiation; however, high concentrations of sulfate aerosols catalyze ozone-destroying reactions on the surfaces of polar stratospheric clouds. Therefore, implementing stratospheric aerosol injection on a planetary scale will inevitably produce severe thinning of the global ozone shield.Sulfate aerosols dispersed into non-polar stratospheric regions will catalyze significant net ozone depletion even in the absence of polar stratospheric cloud formations.
- Cognitive Ethologist: Bottlenose dolphins emit individual-specific signature whistles. When acoustic playback experiments broadcast synthetic copies of these signature whistles, dolphins respond preferentially to the synthesized calls of maternal relatives rather than familiar non-kin. Thus, dolphin kin recognition is mediated primarily by the frequency contour of signature whistles rather than by subtle variations in individualized vocal timbre.The acoustic synthesis process used in the playback experiments did not preserve the individualized vocal timbre of the dolphins whose whistles were recorded.
Answer
Argument 1 matches the assumption regarding non-vector human transmission mechanisms; Argument 2 matches the assumption regarding the nonexistence of viable long-horizon arbitrage strategies; Argument 3 matches the assumption regarding ozone catalysis outside polar stratospheric cloud conditions; Argument 4 matches the assumption regarding the acoustic elimination of vocal timbre in synthesized playbacks.
Each correctly matched pair identifies a foundational unstated bridge or defender assumption. In every case, applying the Negation Test reveals that denying the matched premise destroys the inferential link between the stated premises and the author's specific conclusion.
Step-by-Step Solution
Key Concept
Necessary Assumption: Identifying unstated premises required by an argument's logic via the Negation Test.