For a table-based command-of-evidence question, break the claim into all of its required components and make the same comparison in every relevant condition. Prefer the choice that directly compares the experimental groups and supports the claim's full scope; reject choices that use accurate but incomplete within-group comparisons.
Hints
- Hint 1
Separate the claim
Look for evidence of both a disadvantage under predictable conditions and an advantage under changing conditions.
- Hint 2
Use consistent comparisons
For each test condition, compare the fluctuating-history rate directly with the constant-history rate.
- Hint 3
Interpret the differences
Consider what a negative or positive fluctuating-minus-constant difference would indicate in each condition.
Step-by-step
- Step 1
Identify the required comparisons
The claim has two components: fluctuating-history populations should perform worse when salinity remains predictable but better than constant-history populations after either kind of abrupt shift.
- Step 2
Calculate the between-history differences
Subtract the constant-history rate from the fluctuating-history rate in each condition. The differences are under unchanged salinity, after an increase, and after a decrease.
- Step 3
Interpret the signs
The negative first difference represents lower growth under predictable conditions, while both positive shift-condition differences represent higher growth after abrupt changes. Therefore, the correct answer is The fluctuating-history rate minus the constant-history rate was under unchanged salinity, after an increase, and after a decrease.