Q13 - A recent study concludes that

[ccalice21]

I identify the dispute as the inconsistency between growth rings that can only be found in cold blooded animals and the dense blood vessels that indicate, however, that they are warm blooded.

I don't see how E can resolve it. By whatever means the animals abtain dense blood vessels (by having a particular gene or other means), wouldn't the presence of dense blood vessels compel the result that they are warm blooded? Since the last sentence of the question stem phrases it as "had to be"?

I chose D ( though it now seems it doesn't even withstand my own argument above). I think it to some degree undermines the connection between having dense blood vessel and being warm blooded.

Thanks in advance!

[jiyoonsim]

This was a strange question, since you are not only required to resolve the paradox, but also to tip the scale to one of the two sides.

I eliminated D, since I thought it doesn't help resolving the paradox, but actually deepening the mystery.

So this bird has growth rings (cold blood) AND dense blood vessels (warm blood). If D is true, then what is this animal? D explains nothing about the animal's growth rings. This is similar with B, which is what I chose for the answer. B doesn't explain anything about the dense blood vessles.

IMO B and D would have made a pretty good answer if this was just another weakening question or paradox question, but like I wrote before, we have to do resolve the paradox while siding with one of two parties in this question. For that, E works better. It resolves the paradox (now we know why this particular animal has both traits) AND sides with the cold blood party.

That's how I studied this question...hope this helps. If anyone else has better way of understanding this, please share!

[ManhattanPrepLSAT1]

Nice work jiyoonsim!

I don't see how E can resolve it. By whatever means the animals abtain dense blood vessels (by having a particular gene or other means), wouldn't the presence of dense blood vessels compel the result that they are warm blooded? Since the last sentence of the question stem phrases it as "had to be"?

We're asked to select an answer choice that will help resolve the dispute in favor of one of the two parties to the dispute. That will inevitably mean that we will challenge one of the two views. So while the second study does use the words "had to be" we will be attacking one of the two views. The word resolve is used in a different context on this question. Typically on questions that ask you to resolve an apparent discrepancy we want to show how both claims can be true at the same time. However on this question, we want to show how one of the studies is true and the other not. So it's okay to go against the words "had to be."

The dispute is whether these prehistoric birds were warm blooded or cold blooded. Answer choice (E) would suggest that the prehistoric birds were cold blooded (or at least would do more than any of the other answer choices to push in favor of one of two viewpoints). If some cold-blooded animals had a gene that was responsible for both characteristics the studies are using to argue towards different perspectives, that would resolve the discrepancy in favor of the prehistoric birds being cold-blooded. Because now the dense blood vessels would necessarily be indicative of being warm-blooded.

Let's just look at the incorrect answers though:

(A) doesn't address the issue of whether the prehistoric birds were themselves warm-blooded or cold-blooded.
(B) fails to address the dense blood vessels. Of course cold-blooded animals will have other traits than the growth rings, but we need to know that they could also have the dense blood vessels.
(C) doesn't address the issue of whether the prehistoric birds were themselves warm-blooded or cold-blooded.
(D) doesn't go so far as to say that dense blood vessels are sometimes found in cold-blooded animals. Or if it had said that the growth rings are sometimes also found in warm-blooded animals, that might have pushed the argument in the other direction sufficiently.

Hope that helps! Let me know if you have further questions on this one.

[Shiggins]

I am having trouble with what E is generally saying. If the gene responsible for growth rings is also responsible for blood vessels. Could that mean that it brings both terms into play. In that case is it saying that blood vessels can be insufficient in determining that the birds "had to be warm blooded."

Is the last sentence saying that dense blood vessels are sufficient to conclude that the prehistoric creatures were warm blooded. I just felt very confused on this question. Any help would be appreciated.

[ManhattanPrepLSAT1]

The argument is set up to suggest that growth rings would imply that the prehistoric birds were cold-blooded. The dense blood vessels are thought to imply that the prehistoric birds were warm-blooded.

Answer choice (E) suggests that the dense blood vessels do not support the idea that the prehistoric birds were warm-blooded since according to answer choice (E) it's possible that cold-blooded birds could also have dense blood vessels.

Answer choice (E) does not prove that the birds were cold-blooded, but could be used to support that claim. It eliminates the apparently contradictory evidence by suggesting that both characteristics could be associated with cold-blooded animals.

Does that answer your question?

[ywan1990]

Can someone help to explain why (d) is incorrect?

(D) basically weakens the argument underlying the second study. In other words, it insists that 'having dense blood vessels' does not necessarily means 'it is a warm-blooded species'. So even the prehistoric birds had dense blood vessels, it does not necessarily follow that they had to be warm-blooded.

So can't we conclude the dispute has been resolved as we have found the 'blood vessel' argument unsound?

Note also, I understand that (e) is correct, but it seems to me that it resolves the dispute also by denying the necessary condition (if dense blood vessels, then must be warm-blooded) underlying the second study.

[sumukh09]

D) doesn't really help favour one theory over the other. Saying all warm blood species do not have dense blood vessels isn't enough to conclude that the birds were cold blooded species. Remember we're looking for an answer choice that helps one of the two views in the stimulus and points us in the direction of favouring one theory over the other. D doesn't give us enough information to do that. All D says is that it's possible that the birds could be cold blooded given that not all warm blooded have dense blood vessels; but do we need ALL warm blooded species to have dense blood vessels? Nope.

E, on the other hand, helps reconcile the stimulus since it takes into account both properties (growth rings and dense blood vessels) but does so in a way that helps us favour the theory that the birds were cold blooded species instead of warm.

[theanswer21324]

Hi Matt

Thanks for the helpful response. The thing that threw me off about (E) was that it said "some cold-blooded species - which sounded a bit vague. It seemed likely that the birds might not have fallen into this category.

For resolve the dispute questions, are you basically saying that a vague answer choice is acceptable since it leaves open the possibility that it could happen? (though not necessarily)

[Mab6q]

I understand that E is the better answer choice, but I cant understand why A would not work as a strengthener if it shows us that this change from cold to warm blooded or vice-versa is possible. Wouldn't that strengthen it just a little?

Obliged,

[WaltGrace1983]

Hi Matt

Thanks for the helpful response. The thing that threw me off about (E) was that it said "some cold-blooded species - which sounded a bit vague. It seemed likely that the birds might not have fallen into this category.

The word "some" is incredibly tricky in strengthen/weaken questions. Read this explanation and the explanation in pink for the details. However, we have to realize that this question has two inherently conditional statements:

(1) Growth Rings → Cold-Blooded
(2) Dense Blood Vessels → Active → Warm-Blooded

One scientist believes that growth rings are enough to ensure cold-blooded while another scientist believes that dense blood vessels is enough to ensure warm-blooded. We have to show, in some way, that either (1) growth rings does NOT necessarily entail cold-blooded or (2) that dense blood vessels does NOT necessarily entail warm-blooded.

For (1), we could say that what these scientists "thought" is not sufficient, i.e. though scientists "thought" that growth rings were found ONLY in cold-blooded animals they were wrong AND we should also probably show that these blood vessels do provide sufficient evidence that this bird was warm-blooded.

For (2), we could show that dense blood vessels could indeed be an aspect of being cold-blooded or perhaps that cold-blooded animals who are NOT active actually had warm-blood or something similar. Also, since we want to tip the scales in one direction, we should probably include something about those growth rings.

Now let's move onto the answer choices...

(A) This is not what the argument hinges upon. It would be different if one side said that "These birds are warm-blooded because they descended from warm-blooded species." However, this simply doesn't do that much because the evidence is based upon either growth rings or blood vessels - not on evolution.


In fairness though, this would VERY SLIGHTLY strengthen the idea that these prehistoric birds could be cold-blooded. However, the "very slight" strengthening this does does not match up with the task of relating an answer choice to the evidence, nor does it really sufficiently strengthen in the first place.


(B) To me, this is just completely useless. So cold-blooded species have other physical traits. So what? We only see that (growth rings) → (cold-blooded). We have no evidence saying that (cold-blooded) → ONLY (growth rings). This simply doesn't answer the question of which group this prehistoric bird belongs to, the cold-blooded or the warm-blooded.

(C) This is similar to (B). It just simply doesn't do anything. We want to know MORE information about this prehistoric bird, NOT less! This just adds to the mystery. In addition, we are concerned with prehistoric birds - not modern birds.

(D) Such a tempting answer! Before I looked at (E), I actually circled this one, thinking that "there is no way (E) is going to be stronger than this." I was wrong!

This answer is decent because it shows that ~(dense blood vessels → warm-blooded). In other words, dense blood vessels does not necessarily entail warm-blooded. (D) seems to say, "hey scientist #2. You know that evidence you have for why this prehistoric bird was warm-blooded. Well it doesn't really tell us much because some warm-blooded species do not have dense blood vessels." This seems like a good weakener for scientist #2. But is it a strengthener for scientist #1?

No.

Do you geeks agree with all of that in blue? ^^^

(E) is a bit better. Why? Because it matches our task. Our task is to strengthen one side over the other. (D) weakens one side but fails to strengthen one side. Look at (E) and you can see why this is better.

It says that there are some animals that have growth rings (thus are cold blooded) AND dense blood vessels. So basically, here is what is going on:


(some) cold-blooded animals → (growth rings & dense blood vessels)


So what is exactly going on?

(1) If we know that there are some species that are cold-blooded and have dense blood vessels. We know that there are some animals with dense blood vessels who are ~(warm-blooded). This weakens scientist #2 in the same way that (D) does.

(2) If there are growth rings, the scientists safely assume that the animal is cold-blooded. We have growth rings in this prehistoric bird, thus we can assume that this animal is cold-blooded. This strengthens scientist #1.

(3) It explains the discrepancy, showing why a prehistoric bird can have both dense blood vessels AND growth rings and not be both warm-blooded and cold-blooded (because, that is impossible btw)

An analysis of "Some": 29.1.16

Taken from that thread...

A Discussion of "Some"

I could be wrong. However, I think I have figured out the frame of mind for helping one to decide when "some" is relevant.

Think about this like the negation test. I think many people (and I am totally guilty of this too ) totally misunderstand the negation test. I'll post an example Christine gave that very succinctly shows what's up with that "negation test" (you'll see why this is relevant...assuming my thoughts are good ones!)

Christine wrote:
The negation test is unfortunately very often misunderstood. To "destroy an argument", the negation of a necessary assumption does not have to make the conclusion categorically false, it merely has to make it unsupported. In other words, the 'destruction' is not so much the conclusion as it is the link between the premise and the conclusion.

Take a crazy simple example:
PREMISE: All boys like sports.
CONCLUSION: Andy likes sports.

This argument is clearly assuming that Andy is a boy. That's necessary to the argument. If we negate it, we get "Andy is not a boy". Now, if Andy is a girl, it is still possible that she likes sports, right? If Andy is a girl, we have NO IDEA about her sports preference, and there would be zero connection between the premise and the conclusion. The conclusion would not be definitively false, but it would be wholly unsupported.


With that in mind, I think "some" might work in a similar fashion here. Let's go back to the argument with the new answer choice inserted:

Proto-Indo-European (PIE) lacks a word for "sea"
+
PIE has a word for "winter" and "snow"
+
But some languages lack words for prominent elements of the environments of their speakers
→
People who spoke (PIE) lived in a climate that was (1) cold; (2) isolated from the ocean or sea

Uh oh. This would basically invalidate the connection between the premises and the conclusion! This wouldn't make the conclusion completely defunct - far from it actually. However, if we say, "you know those premises you have there? Well we cannot really form an argument on them. Why? Well because it is actually the case that some languages simply don't include prominent elements of the environment of their speakers." If we say this, all of a sudden our argument falls apart.

Again, it doesn't INVALIDATE the argument, but it makes the conclusion NOT FOLLOW from the premises that are meant to support it.

Notice what's really happening in the assumption - the argument is assuming that language is enough information to allow us to draw a conclusion about environment. The assumption is inherently a conditional! "If [language] then [environment]". We want to damage that conditional. What do we need to call a conditional statement a liar? All we need to do is show that sometimes it doesn't work.

In other words, if an argument makes an assumption that one thing is enough to guarantee the conclusion, then showing that things just don't ALWAYS work that way absolutely damages that assumption.

[pewals13]

How should the core be isolated? How should we know the dispute is about evidence and not about the ultimate competing conclusions?

[tommywallach]

Hey Pewals,

There isn't really a core here in the typical sense. And the correct answer only has to be the one that accomplishes the task at hand (i.e. resolve the paradox and tilt it in the appropriate direction), so whether the correct answer is about the evidence or the conclusions, it should accomplish that (but given that we're trying to argue towards a conclusion, the odds are good we will be doing that through evidence).

-t