Birds of many species ingest foods containing carotenoids, pigmented molecules that are converted into feather coloration. Coloration tends to be...
GMAT Information and Ideas : (Ideas) Questions
Birds of many species ingest foods containing carotenoids, pigmented molecules that are converted into feather coloration. Coloration tends to be especially saturated in male birds' feathers, and because carotenoids also confer health benefits, the deeply saturated colors generally serve to communicate what is known as an honest signal of a bird's overall fitness to potential mates. However, ornithologist Allison J. Shultz and others have found that males in several species of the tanager genus Ramphocelus use microstructures in their feathers to manipulate light, creating the appearance of deeper saturation without the birds necessarily having to maintain a carotenoid-rich diet. These findings suggest that ______
Which choice most logically completes the text?
individual male tanagers can engage in honest signaling without relying on carotenoid consumption.
feather microstructures may be less effective than deeply saturated feathers for signaling overall fitness.
scientists have yet to determine why tanagers have a preference for mates with colorful appearances.
a male tanager's appearance may function as a dishonest signal of the individual's overall fitness.
Step 1: Decode and Map the Passage
Part A: Create Passage Analysis Table
| Text from Passage | Analysis |
|---|---|
| "Birds of many species ingest foods containing carotenoids, pigmented molecules that are converted into feather coloration." |
|
| "Coloration tends to be especially saturated in male birds' feathers, and because carotenoids also confer health benefits, the deeply saturated colors generally serve to communicate what is known as an honest signal of a bird's overall fitness to potential mates." |
|
| "However, ornithologist Allison J. Shultz and others have found that males in several species of the tanager genus Ramphocelus use microstructures in their feathers to manipulate light, creating the appearance of deeper saturation without the birds necessarily having to maintain a carotenoid-rich diet." |
|
Part B: Provide Passage Architecture & Core Elements
Main Point: Some tanager species can create the appearance of deep coloration without the dietary investment that would make such coloration an honest signal of fitness.
Argument Flow: The passage establishes that deeply saturated bird coloration typically represents honest signaling because it requires carotenoid consumption that provides health benefits. However, new research shows some tanagers can achieve the appearance of deep saturation through structural manipulation rather than diet, which disrupts this honest signaling system.
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 traditional system depends on honest signaling - deep colors reflect actual carotenoid consumption and health benefits
- But Shultz found tanagers can create deep-looking colors WITHOUT the carotenoid diet
- This means their appearance doesn't necessarily reflect their actual fitness level
- The logical conclusion is that this creates the potential for dishonest signaling
individual male tanagers can engage in honest signaling without relying on carotenoid consumption.
- Claims tanagers can do honest signaling without carotenoids
- This misses the point - honest signaling requires the actual health benefits from carotenoid consumption
feather microstructures may be less effective than deeply saturated feathers for signaling overall fitness.
- Suggests microstructures are less effective than deeply saturated feathers for signaling
- The passage doesn't compare effectiveness - it shows microstructures can create the same appearance
scientists have yet to determine why tanagers have a preference for mates with colorful appearances.
- Claims scientists haven't determined why tanagers prefer colorful mates
- The passage already explains this - deep colors signal fitness to potential mates
a male tanager's appearance may function as a dishonest signal of the individual's overall fitness.
- Recognizes that if appearance doesn't reflect actual carotenoid consumption/health benefits, it's dishonest signaling
- This directly follows from the logic presented