Question 94·200 Super-Hard SAT Reading Questions·Information and Ideas
The Dietary Diversity Hypothesis (DDH) posits that animals inhabiting more seasonal environments mitigate periodic food shortages by adopting broader diets. Using data from more than 900 bird species worldwide, Marta Álvarez and colleagues quantified environmental seasonality with index (higher indicates greater seasonality) and characterized diet breadth with two positive measures—prey taxonomic richness () and foraging versatility (). They argue that their results are inconsistent with the DDH.
Which finding, if true, would most directly support Álvarez and colleagues’ claim?
For questions asking which finding best supports a claim about a hypothesis, restate the hypothesis as a clear directional prediction (e.g., “as increases, and should increase”). Then interpret the claim (“inconsistent with the hypothesis” means the predicted pattern should fail). Eliminate choices that match the predicted pattern or don’t address the relevant variables, and pick the option that most directly contradicts the prediction on the key measures.
Hints
Clarify the role of each variable
Identify what , , and each represent and how changes in and relate to diet breadth.
Turn the hypothesis into a direction of change
If DDH says more seasonality leads to broader diets, what direction of relationship between and each diet variable ( and ) should you expect?
Link “inconsistent” to what you should look for
You want a finding that goes against the DDH’s expected pattern and that directly involves with both measures of diet breadth, and .
Step-by-step Explanation
Restate what the DDH predicts
The Dietary Diversity Hypothesis (DDH) says that animals in more seasonal environments cope with food shortages by eating a broader variety of foods.
In this study:
- = how seasonal the environment is (higher → more seasonal)
- and are positive measures of diet breadth (higher or → broader diet)
So, if the DDH is correct, then as increases, and should also increase.
Translate the hypothesis into correlations
"More → broader diet" implies:
- and should be positively correlated.
- and should be positively correlated.
A positive correlation means the two values tend to move in the same direction; a negative correlation means they tend to move in opposite directions.
Use the authors’ claim (“inconsistent with the DDH”)
If Álvarez and colleagues are right that their results are inconsistent with the DDH, then their data should fail to show the DDH’s predicted positive relationships between and both measures of diet breadth ( and ).
Evaluate the choices against the DDH prediction
- A result that is negative for both – and – most directly contradicts the DDH (it suggests more seasonality goes with narrower diets on both measures).
- Results showing no relationship or mixed directions (one measure contradicts DDH, the other does not) are less direct because they don’t cleanly oppose the DDH across both measures.
Therefore, the correct answer is: “Álvarez and colleagues’ analysis revealed a consistently negative correlation between and and between and .”