PT102.S3.Q9

PrepTest 102 - Section 3 - Question 9

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Ornithologist: Support The curvature of the claws of modern tree-dwelling birds enables them to perch in trees. ███ █████ ██ █████████████ ███ ████████ █████ ████████ █████████ ████ ███████ █████████ ████ ████ ████ ███████ ███ ████████ ██ █████ ██ ████ ██████ ██████████ ████████████ ███ ████████ █ █████████████ █████████

███████████████ ███ ███ ███████ ██ █████ ██ █████ ██ ███ ████ ████████ ████ ████████████ ███ █ █████████████ █████ ████████ ████ █████ ████ ███████ ██ ██████ ███ ████████ ███ █████████ ████████████████

Analysis: Counter-Argument

The ornithologist points out that the curvature of the claws of modern tree-dwelling birds is what allows them to perch in trees, and Archeopteryx's claws had a similar curvature. The ornithologist concludes that Archeopteryx was a tree-dwelling creature. The paleontologist counters that Archeopteryx's ability to perch in trees is not sufficient to show that it was tree-dwelling. As evidence, the paleontologist points to the case of chickens, which spend time perched in trees, but are primarily ground-dwelling birds.

Notice why the paleontologist's response works. The ornithologist argues that because Archeopteryx, like these modern tree-dwelling birds, had curved claws allowing it to perch in trees, Archeopteryx must also share the trait of dwelling in trees (notice that this is a form of argument by analogy). This assumes that just being able to perch in trees necessarily means a creature dwells in trees, and the paleontologist undermines this assumption by providing a counterexample: chickens can perch in trees and yet are mostly ground-dwelling. This example undermines the analogy the ornithologist draws.

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9.

Which one of the following ██ ██ ██████████ ██ █████ ███ ███████████████ █████████ ████████

a

Modern tree-dwelling birds ███ ███ ██████ ███████████ ██ █████████████
Incorrect. The ornithologist's argument isn't based on modern tree-dwelling birds and Archeopteryx being directly related.
6%
b

Archeopteryx made use ██ ███ █████████ ██ ███ ██████
Correct. The ornithologist's assumption is that because Archeopteryx had the ability to perch in trees, it must have dwelt in trees (i.e., made use of that ability). If we negate (B) to say that Archeopteryx did not make use of the curvature of its claws to perch in trees, the ornithologist's argument falls apart.
56%
c

There have never ████ █████████████ █████ ███████ ██████ ██████
Incorrect. This is a tricky answer choice, but imagine negating it: "There have been some tree-dwelling birds without curved claws." Even if this is true, it doesn't matter to the ornithologist's argument, which is only about birds or birdlike creatures with curved claws, like Archeopteryx. The argument isn't about birds without curved claws, so any information about birds without curved claws is irrelevant to the argument. The assumption in the argument isn't that all tree-dwelling birds must have curved claws (tree-dwelling → curved claws), but that having curved claws that allow perching in trees establishes that a creature was tree-dwelling (curved claws → tree-dwelling).
19%
d

Archeopteryx was in ████ ███ ████████ ████████ █████████
Incorrect. The ornithologist's argument wouldn't be undermined even if Archeopteryx were not the earliest birdlike creature.
1%
e

The curvature of ███ █████ ██ ███ ████ █████████ ████████ ███ ███ █████ ████ ████████████ ███ ██████████████
Incorrect. The ornithologist never says that the curvature of the claws is the only evidence that Archeopteryx was tree-dwelling. Her argument is that the curvature of the claws alone is sufficient evidence to show that Archeopteryx is tree-dwelling, and the paleontologist rejects this argument. There could be other evidence that Archeopteryx was tree-dwelling, which neither the ornithologist nor the paleontologist has mentioned.
17%

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