Examkin

Question

Difficulty: HardArgument Analysis and Evaluating Claims

Recent investigations into the foraging strategies of the desert harvester ant (*Veromessor pergandei*) challenge the long-held assumption that seed selection is strictly optimized for caloric yield per unit of handling time. Researchers observed that when presented with two seed species of equal handling effort—one rich in lipids and another in carbohydrates—colonies consistently favored carbohydrate-dense seeds during periods of low ambient humidity, despite lipid-dense seeds offering twice the total energy per mass. The researchers hypothesized that this preference reflects an adaptive mechanism to mitigate physiological desiccation, as the metabolic catabolism of carbohydrates yields significantly more metabolic water per unit of oxygen consumed than does lipid oxidation. However, critics counter that colonies inhabiting subterranean nest chambers display an identical seasonal shift toward carbohydrate-dense seeds despite residing deep underground where ambient temperatures remain stable.

Which of the following, if true, would most weaken the critics' objection to the researchers' hypothesis?

  1. Subterranean nest chambers experience pronounced drops in internal relative humidity during dry seasons as dry surface air circulates through the colony's extensive ventilation shafts.Answer
  2. B
    Lipid-dense seeds contain secondary chemical compounds that reduce metabolic efficiency in harvester ants during high-temperature periods.
  3. C
    Harvester ant colonies with higher overall caloric intake produce significantly more reproductive offspring than colonies that prioritize water preservation.
  4. D
    Carbohydrate catabolism provides immediate glucose necessary for sustained high-intensity foraging excursions across hot desert surface soils.
  5. E
    Colonies residing in coastal regions with constant high humidity do not exhibit any seasonal shift in seed selection.

Answer

The statement explaining that subterranean nest chambers experience pronounced drops in relative humidity during dry seasons due to surface air circulation weakens the critics' objection.
The critics object to the desiccation hypothesis by claiming that subterranean ants live in stable underground environments and thus would not need metabolic water. The correct choice demonstrates that subterranean nests actually undergo significant reductions in humidity during dry seasons because surface air circulates through ventilation shafts. By showing that underground ants are also subject to desiccation risks, this fact disproves the premise of the critics' objection and reinforces the researchers' original hypothesis.

Step-by-Step Solution

1
Identify the researchers' hypothesis and the critics' counterargument.
Researchers argue that ants prefer carbohydrates in dry periods to produce metabolic water against desiccation. Critics object by noting that subterranean colonies show the same preference despite stable underground temperatures.
Understanding the logic of the objection is necessary to determine how to undermine it.
2
Evaluate the underlying assumption of the critics' objection.
The critics assume that residing deep underground insulates the colonies from seasonal humidity drops and desiccation stress.
Attacking an unstated or flawed assumption in an objection invalidates the objection itself.
3
Select the option that shows subterranean colonies do in fact experience desiccation risk during dry seasons.
Demonstrating that surface airflow reduces humidity in subterranean chambers shows that underground colonies also face desiccation stress, neutralizing the critics' counterevidence.
This directly reconciles the subterranean ants' behavior with the researchers' desiccation-mitigation hypothesis.

Key Concept

Evaluating Arguments and Weakening Objections
Rate this question

Topics

Argument Analysis and Evaluating Claims

More questions from this topic