- Tue Nov 10, 2015 6:16 pm
Here's why Answer Choice A (the correct answer choice) does support the idea that plumage variation does not signal individual status.
The author spends roughly lines 16-24 putting forth Rohwer's conclusion, claims, and supporting data. Then, in Line 25, the author turns on Rohwer's conclusion, stating that it is not supported by Rohwer's data (and then proceeds to give data from Rohwer that works against Rohwer's conclusion that "almost without exception birds with darker throats win conflicts with individuals having lighter plumage (line 20).") Lines 30-35 go on to say that it's not so much that dark throat necessarily indicate fighting ability (see the particular data the author used from Rohwer referenced just above), but that dark throats is an indication of age with is an indication of high status (than the lighter throated juveniles).
So, we get back to the question: Why does the author refer to the fact that adult Harris sparrows are usually dark throated (lines 31-32)? Well, it's to show that dark plumage doesn't indicate fighting ability (Rohwer's conclusion) - which would be an individual status signaler, but rather something else, age, which would be a group status signaler.
Hope that helps,