The following text describes research conducted by marine biologist Dr. Sarah Chen.During a three-year study of coral reef ecosystems in...
GMAT Information and Ideas : (Ideas) Questions
The following text describes research conducted by marine biologist Dr. Sarah Chen.
During a three-year study of coral reef ecosystems in the Pacific, Dr. Chen documented an unexpected pattern in fish behavior. She observed that certain species of reef fish consistently altered their feeding schedules during full moon periods, with \(\mathrm{78\%}\) of observed specimens shifting from daytime to nighttime feeding. Additionally, her underwater cameras revealed that these same fish species exhibited increased schooling behavior during these lunar phases, with group sizes averaging \(\mathrm{40\%}\) larger than during new moon periods. Water quality measurements remained constant throughout the study period, and no seasonal variations in food availability were detected. Dr. Chen also noted that fish reproduction rates peaked during full moon cycles, with spawning activity increasing by \(\mathrm{65\%}\) compared to other lunar phases.
Which choice is most strongly supported by the evidence presented in the text?
Coral reef fish feeding patterns are primarily determined by seasonal changes in water temperature.
The availability of prey species in coral reefs fluctuates significantly based on tidal patterns.
Lunar cycles appear to influence multiple aspects of reef fish behavior and biology.
Marine ecosystems function independently of celestial phenomena like moon phases.
Step 1: Decode and Map the Passage
Part A: Passage Analysis Table
| Text from Passage | Analysis |
|---|---|
| 'During a three-year study of coral reef ecosystems in the Pacific, Dr. Chen documented an unexpected pattern in fish behavior.' |
|
| 'She observed that certain species of reef fish consistently altered their feeding schedules during full moon periods, with 78% of observed specimens shifting from daytime to nighttime feeding.' |
|
| 'Additionally, her underwater cameras revealed that these same fish species exhibited increased schooling behavior during these lunar phases, with group sizes averaging 40% larger than during new moon periods.' |
|
| 'Water quality measurements remained constant throughout the study period, and no seasonal variations in food availability were detected.' |
|
| 'Dr. Chen also noted that fish reproduction rates peaked during full moon cycles, with spawning activity increasing by 65% compared to other lunar phases.' |
|
Part B: Passage Architecture & Core Elements
Main Point: Dr. Chen's research revealed that lunar cycles significantly influence multiple aspects of reef fish behavior, including feeding, schooling, and reproduction patterns.
Argument Flow: The passage presents Dr. Chen's unexpected research findings by first establishing the study context, then systematically presenting three different types of behavioral/biological changes all linked to full moon periods. It strengthens these findings by noting that other potential variables (water quality, seasonal food changes) remained constant, suggesting the lunar cycles themselves drive these patterns.
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 passage presents three distinct findings all connected to the same factor: full moon periods
- We see changes in feeding behavior (78% shift), schooling behavior (40% increase in group size), and reproductive behavior (65% increase in spawning) - all during full moons
- The study controlled for other variables like water quality and food availability
- So the right answer should recognize that lunar cycles appear to influence multiple different aspects of fish behavior and biology, rather than focusing on just one type of behavior or suggesting other causes
Coral reef fish feeding patterns are primarily determined by seasonal changes in water temperature.
✗ Incorrect
- Claims feeding patterns are 'primarily determined by seasonal changes in water temperature' which contradicts the passage showing feeding changes linked to lunar phases, not seasons
The availability of prey species in coral reefs fluctuates significantly based on tidal patterns.
✗ Incorrect
- Focuses on prey availability fluctuating with tidal patterns, but passage shows food availability remained constant throughout the study
Lunar cycles appear to influence multiple aspects of reef fish behavior and biology.
✓ Correct
- States that 'lunar cycles appear to influence multiple aspects of reef fish behavior and biology' which perfectly matches the evidence: feeding behavior (78% shift), schooling behavior (40% larger groups), and reproduction (65% more spawning) all linked to full moon cycles
Marine ecosystems function independently of celestial phenomena like moon phases.
✗ Incorrect
- Claims marine ecosystems function 'independently of celestial phenomena' which directly contradicts the entire study's findings