#11 - Recently discovered fossil evidence casts doubt on the

[Administrator]

Complete Question Explanation

Method of Reasoning. The correct answer choice is (E)

The argument starts off by asserting the conclusion that fossil evidence casts doubt on the theory that dinosaurs are more closely related to reptiles than other classes of animals. The argument then supplies observations that fossils indicate characteristics similar to those of birds, and in general to those of warm-blooded animals.

You are asked to identify the method of reasoning, and should focus on the fact that the argument proceeds by making a case for similarities, even though the argument does not convincingly challenge the theory that dinosaurs are more closely related to reptiles, because the argument might only dwell on a small amount fraction of the data.

Answer choice (A) The argument does not discuss the error in any information, only the addition of new information.

Answer choice (B) The argument does not establish any general principle (which would be equivalent to proving that the theory is definitely questionable) and certainly uses no principle to discuss specific cases. In a way, this choice is a Mistaken Reversal of the flow of argumentation, because the argument uses specific cases to attempt to suggest a general principle.

Answer choice (C) Casting doubt on a theory is not the same as dismissing the theory, so this choice is far too extreme and should be immediately eliminated. Furthermore, if you thought that the choice was referring to the actual condition of dinosaurs today, that is a bit absurd for various reasons, and besides the use of the present tense is merely a convention used to discuss literature, theory, classification and so on.

Answer choice (D) The argument does not claim that dinosaurs are definitely warm-blooded, only that because of shared characteristics they may be more like certain warm-blooded animals than cold-blooded animals. Furthermore, this choice is too broad in referring to "all things," because the argument discusses only dinosaurs and birds, and therefore needs not make assumptions about "all things."

Answer choice (E): This is the correct answer choice. Most of the evidence concerns similarities to warm-blooded animals, and overall the argument is geared toward showing that dinosaurs may be more similar to a class of non-reptiles than to reptiles, so either way the argument presents evidence that a past creature was more similar to one group of creatures than to another.

[cmouell]

This is the Method of Reasoning question pertaining to whether or not dinosaurs are closely related to reptiles. The correct answer is E: "presenting evidence that a past phenomenon is more similar to one rather than the other of two present-day phenomena." I just don't follow the answer choice; I can't seem to follow what is being referred to as the two present-day phenomena. In short, I had a tough time unpacking this answer and translating it to the structure of the question stem. I chose answer choice D and am not clear as to why that is incorrect. Thanks.

Very Respectfully, Chris O.

[Dave Killoran]

Hi Chris,

Thanks for the question. Did you happen to check the online explanation for this question? It does reference the reasoning behind the correct answer. Nevertheless, let's take a closer look at what's happening here.

The past phenomenon is dinosaurs (odd to call them a "phenomenon," but that's what they chose to do). Then, once they referred to animals as phenomena, they continued the trend, and the two present-day phenomena are warm-blooded and cold-blooded creatures. the argument goes on at length about how dinosaurs have a bunch of traits of warm-blooded creatures and one that isn't like a cold-blooded creature, justifying the use of "more similar to one" of the phenomena.

With (D), this goes to far and is too absolute. For (D) to be true, the author would have had to say that because all warm-blooded creatures have a certain trait (say, hollow bones) and dinosaurs had that certain trait, then dinosaurs had to be warm-blooded. But, the author is really careful, and never goes nearly that far, instead stating in the opening lines that the new evidence only "casts doubt" on the theory that dinosaurs are more closely related to reptiles.

Please let me know if that helps. Thanks!

[Kelly R]

Hi PS,

Just want to verify that the reasoning I used to eliminate D holds. In general, D seems to be far too absolute in language to describe an otherwise relatively noncommittal argument. More specifically, though, it does not seem as if the author assumes that ALL warm-blooded animals have the warm-blooded traits mentioned in the stimulus (an arched mouth, hollow bones, etc), but instead that these traits are only found in warm-blooded animals. This seems uniquely different from the claim that all warm-blooded animals possess these features. Further, the argument never assumes that ALL dinosaurs possess these warm-blooded traits and are thus warm-blooded creatures, but instead only claims that "some" of the dinosaurs possess these traits. Collectively, then, it seems that the author is only suggesting that dinosaurs might be more closely related to warm-blooded animals than previously assumed. Thanks!

[Paul Marsh]

Hi Kelly! Your reasoning for eliminating (D) looks right on the money. Nice going!

[sdb606]

I'm still having trouble rationalizing away D. I interpret D as saying: "If all dogs have tails, then all things with tails are dogs." Therefore:

• If all dinosaurs are more closely related to non-reptiles, then all animals more closely related to non-reptiles are dinosaurs. The argument does not do this so eliminate D.

• If all birds have hollow bones, all animals with hollow bones must be birds. The argument does not do this so eliminate D.

• If all animals in category A have characteristics B, C, and D, then if a new animal in an unknown category has characteristic D, it must also have B and C and be in category A. If all birds are warm blooded and have hollow bones, then if a dinosaur has hollow bones, it must also be warm-blooded, and therefore less related to reptiles than previously thought. The argument says that only some dinosaurs fit the category of having hollow bones, therefore D is too extreme because D insists on all dinosaurs having a certain characteristic.

Are all of the above points reasons to eliminate D?

[Adam Tyson]

All of that is good and true, sdb606, but there is a faster and easier way to eliminate that answer, and it all comes down to the first word: "assuming." Was the author method of reasoning to make assumptions? Or, was it to present multiple pieces of evidence that collectively support the conclusion that there is some reason to doubt an earlier theory? It sure looks like the latter to me, not the former. The argument isn't about the author's assumption but about their evidence. That made me ready to reject answer D with the first word!

Consider your prephrase, too. Ideally, you would have thought to yourself "the author listed a bunch of specific examples that each individually challenged the theory," or something like that. Answer D shouldn't sound or feel anything like your prephrase, and rather than spend time and effort trying to disprove it you should just reject it for that reason alone. E matches the prephrase, D isn't even close, so E is better. Done!