Over the past three decades, many bird species have altered their migration schedules in response to changing global temperatures. Dr....
GMAT Information and Ideas : (Ideas) Questions
Over the past three decades, many bird species have altered their migration schedules in response to changing global temperatures. Dr. Elena Rodriguez and her research team at the Pacific Flyway Institute conclude that these timing shifts indicate a fundamental adaptation to climate change rather than random behavioral variation. The scientists reached this conclusion after analyzing migration data from over 40 tracking stations across North America, documenting both arrival dates at breeding grounds and departure dates from wintering areas for dozens of species between 1990 and 2020.
Which finding from the research, if true, would most directly support the scientists' conclusion?
Species monitored since 1990 show significantly earlier spring arrivals at northern breeding grounds compared to birds tracked in the 1970s and 1980s.
Migration timing variations among different bird species have remained relatively consistent throughout the three-decade study period.
Among the tracked species, larger birds tend to adjust their migration schedules more gradually than smaller species do.
The arrival dates for spring migration and departure dates for fall migration occur approximately six months apart for most species.
Step 1: Decode and Map the Passage
Create Passage Analysis Table
| Text from Passage | Analysis |
|---|---|
| "Over the past three decades, many bird species have altered their migration schedules in response to changing global temperatures." |
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| "Dr. Elena Rodriguez and her research team at the Pacific Flyway Institute conclude that these timing shifts indicate a fundamental adaptation to climate change rather than random behavioral variation." |
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| "The scientists reached this conclusion after analyzing migration data from over 40 tracking stations across North America, documenting both arrival dates at breeding grounds and departure dates from wintering areas for dozens of species between 1990 and 2020." |
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Provide Passage Architecture & Core Elements
Main Point: Dr. Rodriguez's research team concludes that birds' altered migration timing over the past 30 years represents adaptation to climate change rather than random behavioral variation.
Argument Flow: The passage establishes that bird migration patterns have changed over three decades, then presents Dr. Rodriguez's team's interpretation of these changes as climate adaptation rather than random variation, and finally describes the extensive research methodology that led to this conclusion.
Step 2: Interpret the Question Precisely
This is a fill-in-the-blank question asking us to choose the best logical connector. The answer must create the right relationship between what comes before and after the blank.
Step 3: Prethink the Answer
- The scientists concluded that migration changes represent "fundamental adaptation to climate change rather than random behavioral variation"
- To support this conclusion, we need evidence that shows:
- The changes follow a clear, systematic pattern over time
- The changes align with what we'd expect from climate adaptation
- The changes aren't just random fluctuations
- So the right answer should demonstrate systematic, directional change that supports the adaptation hypothesis rather than suggesting random variation
Species monitored since 1990 show significantly earlier spring arrivals at northern breeding grounds compared to birds tracked in the 1970s and 1980s.
- Shows systematic change over time - earlier spring arrivals comparing recent decades to earlier decades
- Demonstrates exactly the kind of directional, consistent pattern that would indicate adaptation rather than random variation
- Provides the historical comparison needed to show this is a sustained trend, not random fluctuation
Migration timing variations among different bird species have remained relatively consistent throughout the three-decade study period.
- States that timing variations have remained "relatively consistent" throughout the study period
- This actually contradicts the idea of adaptation, since adaptation would involve change over time
Among the tracked species, larger birds tend to adjust their migration schedules more gradually than smaller species do.
- Describes differences between large and small birds in how they adjust schedules
- While interesting, this doesn't address whether the changes represent adaptation vs. random variation
The arrival dates for spring migration and departure dates for fall migration occur approximately six months apart for most species.
- Simply states a timing relationship between spring and fall migration dates
- This is just a general fact about bird migration cycles, not evidence about adaptation vs. random variation