The argument is trying to disprove the hypothesis that flight first developed from marine reptiles since they have scales, which are thought to have developed into feathers.
Why? Other biologists have pointed out that bats have no scales and that non-marine reptiles also have scales. Some insist that tree-dwelling reptiles developed wings to assist their leaps from branch to branch.
So the statement that non-marine reptiles have scales is used as evidence to show that flight did not necessarily first develop from marine reptiles due to their scales, since non-marine reptiles also have scales, i.e. answer choice (A): "It is cited as evidence against the claim that the capacity for flight first developed in marine reptiles."
Hope that was helpful! Please let us know if you have any other questions.
AlexApril 28, 2015
Please explain why not E? Thank you.
NazApril 30, 2015
The first line tells us that some biologists surmise that the capacity for flight first developed in marine reptiles--their feathers having "clearly" developed from scales. However, in the next line we are given two examples as to why "other biologists rightly reject" the suggestion in the first line: (1) "bats have no scales," and (2) "non-marine reptiles also have scales."
The first example rejects the suggestion in the first line because bats have the capacity for flight, but they don't have scales. The second example rejects the suggestion in the first line because non-marine reptiles have scales and non-marine reptiles cannot fly.
We are asked what role is played by the claim that non-marine reptiles have scales, i.e. what role does the second example play?
Well, as discussed above, that specific claim merely gives us an example as to why the biologists from the first line may have been mistaken in their suggestion that the capacity for flight first developed in marine reptiles--their scales having developed into feathers. How exactly does the second example reject this? Again, it gives us an example of an animal that does have scales, i.e. non-marine reptiles, but does not have the capacity to fly.
Thus, answer choice (E) is not correct, because this specific claim--that non-marine reptiles have scales--has nothing to do with mammals without scales. Therefore, this claim cannot "corroborate the observation that some mammals without scales, such as bats, developed the capacity to fly," as answer choice (E) suggests.
Hope that clears things up! Please let us know if you have any other questions.
