Argument question

kovacs
Posts: 33
Joined: Fri Jun 10, 2011 5:29 pm

Argument question

Postby kovacs » Fri Jun 10, 2011 5:41 pm

Hi guys,

This is my first posting so I'm saying hello! I'm studying for the upcoming LSATs and would like some help on an argument question found on the 2011 Princeton Review LSAT study book.

The question:

A study was conducted to determine what impact, if any, last year's aggressive shark-fishing campaign had on the local seal population. Since the campaign began, the seal population has increased by 25 percent. Thus, the removal of large numbers of sharks from the ecosystem allowed the population of seals to increase.

Which of the following, if true, most seriously weakens the argument?

(A) A previously unidentified virus was responsible for the deaths of a large number of sharks in the same area in the last year.
(B) Sharks prey on many species of fish as well as seals.
(C) Excess bait used to lure the sharks provided the seals with a plentiful source of nutrition.
(D) The shark-fishing campaign included many different shark species.
(E) Reducing the shark population has a number of negative side effects on the ecosystem as a whole.

Answer choices B, D, and E are obviously incorrect. But, between A and C, it seems to me like it's a toss up. The correct answer is (C), but why? The Princeton Review states that it is a better answer because (A) addresses the premise, whereas (C) addresses the conclusion. However, I beg to differ. Doesn't (A), the virus that kills a large number of sharks, imply less feasting on seals, so there are relatively a greater number of seals than years past? In other words, the answer should address the INCREASE in seals. Is it because (A) the death of sharks does not necessarily mean an increase in sharks, but just less killing? IF the increase in seals is relative to last year, then how can (A) be a relatively worse answer than (C)?

delusional
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Joined: Thu Jul 15, 2010 7:57 pm

Re: Argument question

Postby delusional » Fri Jun 10, 2011 5:47 pm

kovacs wrote:Hi guys,

This is my first posting so I'm saying hello! I'm studying for the upcoming LSATs and would like some help on an argument question found on the 2011 Princeton Review LSAT study book.

The question:

A study was conducted to determine what impact, if any, last year's aggressive shark-fishing campaign had on the local seal population. Since the campaign began, the seal population has increased by 25 percent. Thus, the removal of large numbers of sharks from the ecosystem allowed the population of seals to increase.

Which of the following, if true, most seriously weakens the argument?

(A) A previously unidentified virus was responsible for the deaths of a large number of sharks in the same area in the last year.
(B) Sharks prey on many species of fish as well as seals.
(C) Excess bait used to lure the sharks provided the seals with a plentiful source of nutrition.
(D) The shark-fishing campaign included many different shark species.
(E) Reducing the shark population has a number of negative side effects on the ecosystem as a whole.

Answer choices B, D, and E are obviously incorrect. But, between A and C, it seems to me like it's a toss up. The correct answer is (C), but why? The Princeton Review states that it is a better answer because (A) addresses the premise, whereas (C) addresses the conclusion. However, I beg to differ. Doesn't (A), the virus that kills a large number of sharks, imply less feasting on seals, so there are relatively a greater number of seals than years past? In other words, the answer should address the INCREASE in seals. Is it because (A) the death of sharks does not necessarily mean an increase in sharks, but just less killing? IF the increase in seals is relative to last year, then how can (A) be a relatively worse answer than (C)?

A is wrong because the way the question is phrased, the shark disease is just another way to get sharks out of the ecosystem. In a way, it would even strengthen the argument. But even without that, C potentially could account for the entire increase, while diminishment by disease is no different than manual removal, so it would weaken the argument more.

redwings15
Posts: 26
Joined: Mon Mar 07, 2011 2:23 am

Re: Argument question

Postby redwings15 » Fri Jun 10, 2011 5:51 pm

(C) makes sense. This is a cause and effect question. Seals increased not because of the shark removal campaign but because of the bait.

kovacs
Posts: 33
Joined: Fri Jun 10, 2011 5:29 pm

Re: Argument question

Postby kovacs » Fri Jun 10, 2011 5:57 pm

I got it to sink after I posted; but thanks for the QUICK responses! You guys are awesome!

Here is what I am thinking: (A) does not address the seals prosperity (increase in population), only the sharks' diminishing population. After the virus kills off most of the sharks, the seals' population may just remain the same as it was before. Whereas, (C) gives us a reason as to why the seal population increased explicitly.

User avatar
Yeshia90
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Joined: Sun Apr 03, 2011 12:23 am

Re: Argument question

Postby Yeshia90 » Fri Jun 10, 2011 6:00 pm

Argument: Removing sharks increased seal population.

A doesn't contradict that at all. It proposes an alternate cause for a removal of sharks from the ecosystem, but not for the increase in seal population.

TMC116
Posts: 287
Joined: Mon Jun 06, 2011 6:08 pm

Re: Argument question

Postby TMC116 » Fri Jun 10, 2011 6:01 pm

Well, for starters, the argument presented is weak because it assumes a causal relationship between the initiative and the change in population. Since the argument is causal, you need to make it less likely that the removal of sharks caused the population of seals to increase.

While it is true that answer choice (A) doesn't relate to the shark fishing campaign (the premise), it still may cause the removal of sharks (the conclusion). So (A) would weaken the initiative mentioned in the premise over the specific cause but it does not weaken the more general cause-effect argument made in the conclusion. The removal of sharks, by the virus, may allow the population of seals to increase by the removal of the shark population. That is, it still may induce the cause mentioned in the stimulus. So, in short, answer choice (A) affirms the causal argument made by the author but simply disagrees over what the cause is.

In that sense, answer choice (A) strengthens the argument.

Answer choice (C), on the other hand, attacks the cause-and-effect argument. It's harder to spot. I guess if there was more bait available then seals would have more access to nutrients. Increased access to bait could allow them to thrive and the population to increase. Answer choice (C) offers an alternative explanation for the increase in seal population. Thus, (C) weakens the causal argument presented by the author

Anyway, that's just my interpretation of those 2 answer choices. I might be off on that so feel free to correct me...

TMC116
Posts: 287
Joined: Mon Jun 06, 2011 6:08 pm

Re: Argument question

Postby TMC116 » Fri Jun 10, 2011 6:06 pm

Haha sorry i didn't see your response about finding the answer.

If i had, i wouldn't posted the long explanation above :oops:

kovacs
Posts: 33
Joined: Fri Jun 10, 2011 5:29 pm

Re: Argument question

Postby kovacs » Fri Jun 10, 2011 6:20 pm

Thanks all explanations help! ^^^^ You've made it clearer!

OK, I'm having more trouble :?
Another question:

In 1940 archaeologists in Costa Rica found a number of huge, human-made stone spheres of apparently ancient origin, but since then little has been learned about them. A primary reason for this is that, after 1940, the spheres became valued as decorations or status symbols, and most have since been moved. This is why the discovery of several spheres in a newly excavated burial site is so important. The same site included gold jewelry in a style that is not known to have existed earlier than 1000 AD, leading some archaeologists to conclude that the stone spheres were will being made as recently as a thousand years ago.

Which one of the following facts, if known, would most strongly support the conclusion of the archaeologists described in the argument?

(C) Archaeological evidence indicates that the spheres were in place before the burial structure in which they were found was erected around them.

(E) Other burial sites similar to the one newly excavated have been definitively dated to within the past thousand years and include depressions that indicate something heavy since stood there but has since been moved.

The correct answer is (E), but why?? (C) states that the spheres existed prior to the burial structure; one burial structure included gold jewelry that is at least 1,000 years old. Thus, should the spheres' age (of at least 1,000 years old) be supported by C? Am I missing something here?

TMC116
Posts: 287
Joined: Mon Jun 06, 2011 6:08 pm

Re: Argument question

Postby TMC116 » Fri Jun 10, 2011 6:33 pm

One thing to note is that the conclusion relates to how recently the stones were made. You are interested in proving that this happened within the last 1000 years

If you look closely, you can match "have since been moved" from the stimulus to "has since been moved" in letter choice (E).

(E) tells us about other sites dated within the 1000 period we're looking for AND it those sites show evidence that something (such as jewelry) was recently moved.

That answer choice, if true, would strengthen the archeologists' argument

kovacs
Posts: 33
Joined: Fri Jun 10, 2011 5:29 pm

Re: Argument question

Postby kovacs » Fri Jun 10, 2011 6:40 pm

I GOT IT! I misinterpreted "included gold jewelry in a style that is not known to have existed earlier than 1000 AD" in the author's passage as meaning that the gold is now being recorded as existed later than 1000 AD. Silly me. It means that the gold is most likely to exist within the last 1,000 years. Thus, the correct answer must support the conclusion and be consistent with WITHIN the last 1,000 years.

Thanks again, TMC116! I'm afraid that there will be more questions to come... :? :roll: :lol: :cry: I find that all of those emoticons are necessary.




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