Question 90·Hard·Inferences
Ecologists studying artificial light’s impact on nighttime pollination monitored two plots of the same alpine flower species. One plot was illuminated nightly by low-intensity LED streetlights, while the other remained in natural darkness. Over four weeks, flowers in the lit plot received 62 percent fewer visits from moths yet ultimately produced about the same number of seeds as flowers in darkness. Subsequent observations revealed that small beetles, rarely seen at the dark plot, foraged frequently on the illuminated flowers. According to the researchers, these findings indicate that ______
Which choice most logically completes the text?
For inference questions describing studies, track (1) what changes between conditions, (2) what outcome stays the same, and (3) any added observation offered as an explanation. Then choose the option that connects those facts with the smallest necessary inference, avoiding answers that introduce new causes or make broad claims beyond the study.
Hints
Locate the key comparison
Focus on the comparison between the lit plot and the dark plot: how do moth visits differ, and how does seed production differ?
Connect moth visits to seed production
If moth visits go down by 62%, what would you normally expect to happen to seed production? Then notice what the study actually reports.
Use the beetle information
Beetles are rarely seen in one plot but frequent in the other. How could that help explain why seed production stays about the same?
Avoid claims that go beyond the study
Be cautious of choices that explain the results by adding a new mechanism (like crowding-out) or making broad claims about what happens in all conditions.
Step-by-step Explanation
Summarize the key facts from the experiment
First, restate the important details in your own words:
- There are two plots of the same alpine flower: one lit by low-intensity LED streetlights, one left dark.
- In the lit plot, flowers received 62% fewer moth visits than in the dark plot.
- Despite this, the lit flowers produced about the same number of seeds as the dark flowers.
- Later observations showed that small beetles (rare in the dark plot) visited frequently in the lit plot.
These are the clues you must connect when choosing the researchers’ conclusion.
Notice the surprising pattern
If moths visit much less often, you might expect fewer seeds.
But the passage says seed production is about the same in both plots. That means something is likely making up for the reduced moth visitation in the lit plot.
Use the beetle observation to explain how seeds stay steady
The passage adds a key follow-up observation: beetles were rarely seen at the dark plot but foraged frequently on illuminated flowers.
That shift suggests that when moth visitation decreases under artificial light, another pollinator group becomes more active on those flowers, helping maintain seed production.
Select the choice that matches all evidence without adding unsupported claims
The best completion is the one that links (1) fewer moth visits, (2) more beetle foraging in the lit plot, and (3) similar seed production.
Therefore, the best answer is:
changes caused by artificial light can prompt other pollinator species to compensate for reduced moth activity, thereby sustaining seed production.