Q9 - Some scientists believe that 65

[jasonxu89]

Why E is the correct answer? E merely provide an alternative explanation for the extinction of the dinosaur but not resolve the discrepancy because the hypothesis is that debris blocked the sunlight and dinosaur died without adequate food. I thought the correct answer would be something explaining why although 6 month is too short but it is still can cause food source vanish....

If E is correct, why not D? They both provide a new perspective to explain the extinction.


Thanks in advance!

[geverett]

Hey! This is my first time posting an explanation on these forums, but I will try my best. This was definitely a question that caused me to pause for a moment so you are not alone in the difficulty it presented.

The paradox: Scientists believe an asteroid struck earth 65 million year ago. The asteroids impact could have hurled enough debris to block sunlight and thrust the earth into an ice age which would have caused the extinction of dinosaurs. However, the scientists have also concluded that most of the debris fell to the earth in 6 months which was not a long enough time to remain in the atmosphere to cause an ensuing ice age.

The question: How is it possible that they could believe the asteroid caused the extinction yet still hold the belief that the large amount of debris leading to the ice age did not cause the extinction?

Paraphrase: There must have been something else that the asteroid triggered either through the impact itself or the debris it threw up into the atmosphere in that 6 month period that led to the extinction.

Answer Choices:
A) Talks about loss of herbivores, but offers no explanation for how all the herbivores could have passed away to begin with.
B) Irrelevant. Does not tell us anything about how the dinosaurs could have become extinct.
C) This was a contender for me, but upon 2nd examination we are not given any information on the amount of debris left in the atmosphere after the 6 month period or how much of a temperature drop would be required to cause an ice age.
D) This was also a contender, but the key in this answer choices is the word "many". Just because many of the dinosaurs were killed by the extinction and subsequent tidal wave does not mean that "all" of them were. To qualify as an extinction it would have to lead to the elimination of "all" of the dinosaurs.
E) By eliminating all of those answer choices we are left with this. Of course it has a feeling of vagueness to it, but we must take it at face value. "Dinosaurs were susceptible to fatal . . . " It has no modifier word like "some" or "all" but since it just point blank says "Dinosaurs." it is safe to say they are talking about all dinosaurs and this answer choice presents an alternative possibility besides an ice age for the asteroid impact causing the extinction of the dinosaurs.

Let me know what you like/dislike about the explanation and I will strive for clarification on any ambiguous points or things I might have overlooked.

[ManhattanPrepLSAT2]

Great explanation! The question would have been a bit different if the stated conclusion was that dinosaurs went extinct because of food disappearing, or because of the lack of sunlight, but the author stops short of that.

Again, terrific explanation -- thank you for contributing to the forums!

[joseph.carroll.555]

Hey! This is my first time posting an explanation on these forums, but I will try my best. This was definitely a question that caused me to pause for a moment so you are not alone in the difficulty it presented.

The paradox: Scientists believe an asteroid struck earth 65 million year ago. The asteroids impact could have hurled enough debris to block sunlight and thrust the earth into an ice age which would have caused the extinction of dinosaurs. However, the scientists have also concluded that most of the debris fell to the earth in 6 months which was not a long enough time to remain in the atmosphere to cause an ensuing ice age.

The question: How is it possible that they could believe the asteroid caused the extinction yet still hold the belief that the large amount of debris leading to the ice age did not cause the extinction?

Paraphrase: There must have been something else that the asteroid triggered either through the impact itself or the debris it threw up into the atmosphere in that 6 month period that led to the extinction.

Answer Choices:
A) Talks about loss of herbivores, but offers no explanation for how all the herbivores could have passed away to begin with.
B) Irrelevant. Does not tell us anything about how the dinosaurs could have become extinct.
C) This was a contender for me, but upon 2nd examination we are not given any information on the amount of debris left in the atmosphere after the 6 month period or how much of a temperature drop would be required to cause an ice age.
D) This was also a contender, but the key in this answer choices is the word "many". Just because many of the dinosaurs were killed by the extinction and subsequent tidal wave does not mean that "all" of them were. To qualify as an extinction it would have to lead to the elimination of "all" of the dinosaurs.
E) By eliminating all of those answer choices we are left with this. Of course it has a feeling of vagueness to it, but we must take it at face value. "Dinosaurs were susceptible to fatal . . . " It has no modifier word like "some" or "all" but since it just point blank says "Dinosaurs." it is safe to say they are talking about all dinosaurs and this answer choice presents an alternative possibility besides an ice age for the asteroid impact causing the extinction of the dinosaurs.

Let me know what you like/dislike about the explanation and I will strive for clarification on any ambiguous points or things I might have overlooked.

Sorry this explanation isn't clicking for me, because I don't see how D is any different from E. For E, just because dinosaurs are susceptible to fatal respiratory problems does not mean that ALL dinosaurs will experience fatal respiratory problems, although it could. And for D, just because an asteroid is large enough to kill many dinosaurs, does not mean that ALL dinosaurs will be killed, although it could. So E then has the same logical force as D, does it not?

[ohthatpatrick]

You're definitely correct that (D) leaves open the possibility that ALL the dinosaurs died from the impact and tidal waves and (E) leaves open the possibility that NONE of the dinosaurs actually contracted fatal respiratory disease.

But on Strengthen, Weaken, Resolve/Explain, we're asked which "most justifies/undermines/explains", so the correct answer normally fails to prove or refute.

How can/should we compare (D)'s ability to explain the extinction of the dinosaurs vs. (E)'s?

(D) gives us certain death in the local vicinity, over a short, but immediate timeframe.

(E) gives us possible death in a global vicinity, over a prolonged, indefinite timeframe.

Given that we're trying to explain global extinction, we have to lean towards (E).

It helps guide your intuition if you know the LSAT pattern of using "many" on incorrect answers on Strengthen, Weaken, and Resolve/Explain.

As soon as I see "many" on any of those question types, I start raising a skeptical eyebrow. Even though 'many' is compatible with 'all', as you said, its actual force is really weak because it's so unspecific.

And, as the original responder noted, (E) applies to dinosaurs generally, so it has the definitive scope of ALL dinosaurs.

I realize ultimately you'll probably still be mad at this problem, which is fair. We don't have to like the credited response; we just have to make peace with why LSAT thinks it's the credited response so we can judge accordingly later.

Hope this helps.

[joseph.carroll.555]

Awesome explanation. Very helpful. Thanks.

[hyl387]

I thought respiratory problems are out of scope as the debris all settled on the ground... Was that a thought too extraneous?

[ohthatpatrick]

It says that the debris settled to the ground within six months, which implies that prior to six months the debris was not on the ground (i.e. in the air).

So (E) would be saying that 6 months of breathing this debris could have caused a respiratory problem.

Hope that helps.

[ganbayou]

So the third sentence starting with "Without adequate sunlight..." is not actually the things the scientists say? It's just a fact or phenomenon the author explains? ( I was confused thinking this third sentence is also explained by the scientists, so when I saw E I thought "but the scientists did not say this is the cause, the cause is due to lack of food..." and eliminated it.)

[ohthatpatrick]

The first two sentences are setting up a POTENTIAL CAUSE for the dinosaurs' demise:
asteroid strikes -> debris goes into atmosphere -> sunlight is blocked and atmosphere is cooled

This stuff DID happen.

What MIGHT have happened as a result was this:
Blocked sunlight -> plants die from no sunlight (killing herbivorous, plant-eating, dinosaurs)
Atmosphere cooled -> prolonged period of low temps -> all dinos die

In that 3rd sentence, there is a conditional verb tense "Without X, food for dinosaurs would have disappeared".

That's a hypothetical. I could say "If John McCain had NOT chosen Sarah Palin as a running mate, he would have won the election."

If the 3rd sentence were reporting fact, it would just use the past tense: "Without X, food for dinosaurs disappeared."

When the question stem asks us to reconcile the scientists' beliefs, we should look for specific words about what the scientists believe.

The 1st sentence says "scientists believe that .. an asteroid struck, ... thereby causing extinction of the dinosaurs."

That belief doesn't specify HOW the asteroid caused the extinction.

One theory would be that it caused the extinction by blocking sunlight from plants and cooling temperatures too much. The problem with that theory is that the debris would only have had those effects for six months, too soon for plants to die or dinos to freeze.

The beginning of that last sentence says that "these same scientists" realize the debris would NOT have killed the plants or frozen the dinos.

(E) is correct because it shows a different way that the asteroid could cause the extinction: breathing in asteroid dust.

[Djkrd92]

Hey Everyone,

Don't forget that the LSAT Logical Reasoning is all about Premises and Conclusions! Almost all questions involve doing SOMETHING to that relationship.

With that in mind let's look at this questions in particular: While everyone did fantastic work on explaining, the thing that made me choose E over D was that D did almost NOTHING to the premise/conclusion relationship in the prompt. Remember, the prompt's discrepancy was the although Scientists believed that the asteroid could've caused a dinosaur extinction BECAUSE of the debris (simplifying it.), but the debris seems to have settled to soon to cause freezing or extinction of plants. So immediately, you should think "hmm then there's probably another reason why the debris could've caused an extinction besides plant extinction and freezing the Earth.

Choice D does NOTHING to this relationship. It's tempting but if you discipline yourself to only look for choices that relate to the premise/conclusion process, you'll eliminate it. It simply mentions nothing about the debris!

Chose E: Voila. Another reason why debris from the asteroid could've caused an extinction. If you plug this into what they gave you, it definitely makes sense that scientists believe debris caused extinction without freezing the Earth or causing plants to do. Debris could've suffocated them!

Hope this helped!

[mitrakhanom1]

When I read the question I assumed that the debris hurled into the atmosphere causing the blocking of the sun and extinction of the dinosaurs was only in the Yucatan Peninsula. Which is why answer choice B was attractive and I picked it rather than answer choice E. I understand why E is correct, but can somebody explain why or how I should have assumed the debris from the asteroid was around the world versus just affecting the Yucatan Peninsula?

[ohthatpatrick]

There aren't really strong textual clues for that. I think LSAT was relying on a little outside awareness.

Since we know that dinosaurs don't exist ANYWHERE on Earth anymore, to say that an asteroid strike caused the extinction of the dinosaurs means that the asteroid strike killed ALL dinosaurs on Earth, not just in the Peninsula.

When they say debris was hurled into "the atmosphere", thereby cooling "the atmosphere", they're referring to Earth's atmosphere.

Even though the atmosphere has different densities at different places on Earth, it's still all one big thing. Different regions of the globe don't have their own atmosphere.

Perhaps more importantly, you should be thinking about your pre-phrase for this paradox question.

How did you structure your
GIVEN THAT ______________ , WHY IS IT THAT _____________ ?

I was thinking
GIVEN THAT the asteroid debris would have settled before plants had disappeared or dinosaurs had frozen
WHY IS IT THAT scientists believe that the asteroid killed the dinosaurs?

Since we're really looking for an explanation for that 2nd half, we're scanning these answers looking for a way that the asteroid could have killed the dinosaurs.

(B) is the opposite of a dino-killer, because it's saying that most dinos lived elsewhere.

The correct answer, (E), IS a dino-killer.

So it's less important that you had the right picture of where the debris was / wasn't ... it's more important that you had organized the paragraph correctly so that you knew you were looking for a story in which dinosaurs WERE killed by the asteroid.

[Emmeline Ndongue]

You're definitely correct that (D) leaves open the possibility that ALL the dinosaurs died from the impact and tidal waves and (E) leaves open the possibility that NONE of the dinosaurs actually contracted fatal respiratory disease.

But on Strengthen, Weaken, Resolve/Explain, we're asked which "most justifies/undermines/explains", so the correct answer normally fails to prove or refute.

How can/should we compare (D)'s ability to explain the extinction of the dinosaurs vs. (E)'s?

(D) gives us certain death in the local vicinity, over a short, but immediate timeframe.

(E) gives us possible death in a global vicinity, over a prolonged, indefinite timeframe.

Given that we're trying to explain global extinction, we have to lean towards (E).

It helps guide your intuition if you know the LSAT pattern of using "many" on incorrect answers on Strengthen, Weaken, and Resolve/Explain.

As soon as I see "many" on any of those question types, I start raising a skeptical eyebrow. Even though 'many' is compatible with 'all', as you said, its actual force is really weak because it's so unspecific.

And, as the original responder noted, (E) applies to dinosaurs generally, so it has the definitive scope of ALL dinosaurs.

I realize ultimately you'll probably still be mad at this problem, which is fair. We don't have to like the credited response; we just have to make peace with why LSAT thinks it's the credited response so we can judge accordingly later.

Hope this helps.

I agree with the local/global vicinity but the "timeframe" thing to me is weird. How do you know when the air problem in E is going to end? in D, yes the debris fell on the ground and ended, however we still don't know how long the subsequent "tidal waves" lasted. I don't think this "timeframe" thing is a clear-cut comparison?