LSAT and Law School Admissions Forum

Get expert LSAT preparation and law school admissions advice from PowerScore Test Preparation.

 Administrator
PowerScore Staff
  • PowerScore Staff
  • Posts: 8950
  • Joined: Feb 02, 2011
|
#22813
Complete Question Explanation

Weaken. The correct answer choice is (B)

This stimulus presents the “comet theory,” a hypothesis which, according to the author, plausibly explains the extinction of the dinosaurs. This is based on the fact that a collision with a sufficiently large comet could have created a dust cloud covering the planet and, in turn, lead to a cooling of the climate for long enough to kill off the dinosaurs. The argument is fairly straightforward, comprised of a conclusion based on a single premise, as follows:

Premise: A big enough collision could have led to a dust cloud covering the Earth, cooling the climate long enough to kill all of the dinosaurs.

Conclusion: The comet theory is a plausible explanation of the dinosaurs’ extinction.

The stimulus is followed by a Weaken question, so the correct answer choice, when added to the information presented in the stimulus, will hurt the author’s argument, and make the comet theory seem a less plausible explanation of the extinction of the dinosaurs.

Answer choice (A): The author of the stimulus does not make the claim that no other theories exist, but rather that the come theory merely provides a plausible explanation. As such, the fact that another school espouses a different theory would not weaken the author’s argument in this case.

Answer choice (B): This is the correct answer choice. If, as this choice provides, around the time of the dinosaur extinction there were other animals that were physiologically similar to dinosaurs, and lived in similar habitats, one would expect that a global cooling sufficient to kill the dinosaurs would also be able to kill those physiologically similar animals. If such animals did not go extinct at the same time, this would support the notion that something else must have happened to kill off all of the dinosaurs. This is a "Cause, No Effect" form of attack.

Answer choice (C): This choice points to a lack of particular hard evidence to be found from dinosaur bones. A lack of evidence, however, does not disprove a theory, and would not weaken the author’s limited assertion that the comet theory, at the very least, provides a plausible explanation for the disappearance of the dinosaurs.

Answer choice (D): It should not be too surprising that some animals survived during the time that the dinosaurs went extinct. The author’s argument is that a comet could have created a dust cloud big enough to reduce the Earth’s temperature and kill all of the dinosaurs. But the author does not claim that such a cooling would have killed every species on the planet, so this choice does not weaken the author’s argument and should be removed from contention in response to this Weaken question.

Answer choice (E): This choice has no effect on the strength of the author’s argument. The consequences of a comet collision with Earth do not need to be fully understood in order for the author to conclude that the comet theory provides a plausible explanation of the disappearance of the dinosaurs.
 olafimihan.k
  • Posts: 25
  • Joined: Jul 04, 2017
|
#36830
Couldn't the same explanation that went for Answer choice D go for Answer choice B? The species that were similar to them in physiology and habitat were simply similar but not exactly dinosaurs. I could be reading too much into it, but the reason I didn't pick B was because the stimulus specifically mentioned dinosaurs.
 andriana.caban
  • Posts: 142
  • Joined: Jun 23, 2017
|
#36840
For me, I knew that either choice B or choice D was correct. However, I couldn't differentiate between the two. What makes B different from D?

B: 'Various species"

D: 'Many species"

These two differentiations is what threw me off when answering the question, causing me to eliminate the two and instead choose a question choice I knew was wrong, like choice A.
 AthenaDalton
PowerScore Staff
  • PowerScore Staff
  • Posts: 296
  • Joined: May 02, 2017
|
#36917
Hi Andriana,

Answer choice (D) is not as strong as answer choice (B) because it doesn't account for how "many other animal species" could be very dissimilar from dinosaurs. It's possible that weather conditions that are fatal to dinosaurs (cold weather, lack of sun, little available vegetation) would have little impact on other, hardier species that are very dissimilar from dinosaurs.

For answer choice (D), consider that many other animal species alive at the same time as dinosaurs might have thrived in the temporarily cold climate caused by the comet -- perhaps animals that prefer an arctic environment, animals that are very robust and could survive most anything (like cockroaches), or animals that live below ground. The survival of those animals is really irrelevant to the survival of dinosaurs because they don't depend on the same conditions.

By contrast, in answer choice (B), we're told that animals which are physically similar to dinosaurs and presumably depended on the same weather patterns, food sources, etc. survived while dinosaurs did not. This undercuts the comet theory since if animals very similar to dinosaurs survived while dinosaurs did not, perhaps something other than a comet led to the dinosaurs' demise.

I hope this helps! Good luck studying,

Athena Dalton
 jessicamorehead
  • Posts: 84
  • Joined: Jul 07, 2017
|
#37399
I got answer choice C - as I thought that was a data attack, is it not? Why is B correct/ how is it different from D?
 andriana.caban
  • Posts: 142
  • Joined: Jun 23, 2017
|
#37488
Thanks Athena Dalton, it did help!
 Eric Ockert
PowerScore Staff
  • PowerScore Staff
  • Posts: 164
  • Joined: Sep 28, 2011
|
#37726
Jessica

Answer (C) is really talking about a lack of evidence with regard to one potential source. That doesn't hurt the argument. For one, there could be many other sources of evidence for the explanation even if a study of skeletons doesn't show it. In addition, the author never cited dinosaur skeletons as evidence for the theory. So an answer that questions the usefulness of dinosaur skeletons does not really weaken this argument.

For answers (B) and (D) I would just point to Athena's previous explanation in this thread, as my explanation would simply reiterate her points. But the bottom line is that (B) has everything (D) has, and then some additional information that shows these animal species to be comparable to dinosaurs. That undoubtedly makes (B) a BETTER answer than (D).

Hope that helps!
 JayI
  • Posts: 4
  • Joined: Jul 27, 2017
|
#38452
Administrator wrote:Complete Question Explanation

Weaken. The correct answer choice is (B)

This stimulus presents the “comet theory,” a hypothesis which, according to the author, plausibly explains the extinction of the dinosaurs. This is based on the fact that a collision with a sufficiently large comet could have created a dust cloud covering the planet and, in turn, lead to a cooling of the climate for long enough to kill off the dinosaurs. The argument is fairly straightforward, comprised of a conclusion based on a single premise, as follows:

Premise: A big enough collision could have led to a dust cloud covering the Earth, cooling the climate long enough to kill all of the dinosaurs.

Conclusion: The comet theory is a plausible explanation of the dinosaurs’ extinction.

The stimulus is followed by a Weaken question, so the correct answer choice, when added to the information presented in the stimulus, will hurt the author’s argument, and make the comet theory seem a less plausible explanation of the extinction of the dinosaurs.

Answer choice (A): The author of the stimulus does not make the claim that no other theories exist, but rather that the come theory merely provides a plausible explanation. As such, the fact that another school espouses a different theory would not weaken the author’s argument in this case.

Answer choice (B): This is the correct answer choice. If, as this choice provides, around the time of the dinosaur extinction there were other animals that were physiologically similar to dinosaurs, and lived in similar habitats, one would expect that a global cooling sufficient to kill the dinosaurs would also be able to kill those physiologically similar animals. If such animals did not go extinct at the same time, this would support the notion that something else must have happened to kill off all of the dinosaurs. This is a "Cause, No Effect" form of attack.

Answer choice (C): This choice points to a lack of particular hard evidence to be found from dinosaur bones. A lack of evidence, however, does not disprove a theory, and would not weaken the author’s limited assertion that the comet theory, at the very least, provides a plausible explanation for the disappearance of the dinosaurs.

Answer choice (D): It should not be too surprising that some animals survived during the time that the dinosaurs went extinct. The author’s argument is that a comet could have created a dust cloud big enough to reduce the Earth’s temperature and kill all of the dinosaurs. But the author does not claim that such a cooling would have killed every species on the planet, so this choice does not weaken the author’s argument and should be removed from contention in response to this Weaken question.

Answer choice (E): This choice has no effect on the strength of the author’s argument. The consequences of a comet collision with Earth do not need to be fully understood in order for the author to conclude that the comet theory provides a plausible explanation of the disappearance of the dinosaurs.
Hi,

I have a question about appropriate scope. I have selected D because it challenged the data "specific to dinosaur extinction". While I understand what was mentioned about B being the correct choice, I thought of it (and D) as out of scope since it does not talk about Dinosaurs. How should I approach determining scope for answer choices as they relate to the stimulus?

Thank you.
 AthenaDalton
PowerScore Staff
  • PowerScore Staff
  • Posts: 296
  • Joined: May 02, 2017
|
#38479
Hi Jay,

Good question!

The question stem here says we are to assume that the facts in each answer choice are true, and then assess their impact on the argument. For this type of question, you can expect that the new information provided will be beyond the scope of what's mentioned in the stimulus. So don't automatically discard an answer if it brings in new information! :)

The argument is using causal reasoning, essentially that:

Cause :arrow: Effect
Dust Cloud :arrow: Dinosaur Extinction

This argument can be attacked by showing that the cause occurred without the effect. Both answer choices (B) and (D) are discussing situations where the dust cloud (cause) occurred during the same period of the dinosaurs' extinction, but extinction (effect) did not occur.

If it were true that a really similar species to dinosaurs experienced the same dust cloud environment at the same time as the dinosaurs, yet survived, we would be less likely to credit the dust cloud for causing the dinosaurs' extinction. So even though (B) isn't specifically discussing dinosaurs, it is discussing information that's relevant to the argument about their extinction (same dust cloud, same time period, etc).

I hope this clears things up. Good luck studying!

Athena
 jessamynlockard
  • Posts: 42
  • Joined: Jan 15, 2018
|
#44714
Should we be skeptical of answer choices like A that don't contain any real argument/don't engage with the argument and are just making an appeal to the authorities?

Get the most out of your LSAT Prep Plus subscription.

Analyze and track your performance with our Testing and Analytics Package.