A favored theory to explain the extinction of dinosaurs, together with

Question

A favored theory to explain the extinction of dinosaurs, together with many other species, has been the globally catastrophic collision of a large asteroid with the Earth. Supporting evidence is an extraterrestrial chemical element in a layer of dust found worldwide at a geological level laid down contemporaneously with the supported event. A new competing theory contends that any asteroid impact was irrelevant, because it was massive volcanic activity that caused the extinctions by putting enough dust into the atmosphere to cool the planet. The Deccan region of India contains extensive volcanic flows that occurred within the same time period as the supposed asteroid impact and the extinctions.

The new theory assumes that

(A) the massive volcanic activity was not caused by the impact of an asteroid 
(B) no individual dinosaurs survived the impact of the asteroid, if it occurred 
(C) the extinctions took place over a longer time period than they would have if caused by the impact of an asteroid 
(D) other volcanic eruptions were not occurring at the same time as those in the Decean region 
(E) it is not possible to determine which would have occurred first, the volcanic flows in the Decean region or the supposed impact of an asteroid

Source: LSAT

Same passage with different stem question:  LINK

abhishekdadarwal2009 · Accepted Answer

The new theory assumes that

(A) the massive volcanic activity was not caused by the impact of an asteroid 
(B) no individual dinosaurs survived the impact of the asteroid, if it occurred 
(C) the extinctions took place over a longer time period than they would have if caused by the impact of an asteroid 
(D) other volcanic eruptions were not occurring at the same time as those in the Decean region 
(E) it is not possible to determine which would have occurred first, the volcanic flows in the Decean region or the supposed impact of an asteroid

The alternate theroy provides an alternate reason for the extinction of the dianosours and to provide an alternate reason the theorist whould have to belive and expalin that the two events were not interdependent to each other and the astroid did not cause the eruption of the volcano in this case.If the two are interdependent then the argument would break and the conclusion could not be reached. so we much select a choice that addresses this that the erruption of the volcano was not due to the astroid collision.

Option A is corretly addressing the fact mentioned above and is the correct choice.

Option A is corretly addressing the fact mentioned above and is the correct choice.

AkshdeepS · Answer

The new theory assumes that

(A) the massive volcanic activity was not caused by the impact of an asteroid

(B)  no individual dinosaurs survived the impact  of the asteroid, if it occurred

(C) the  extinctions took place over a longer time period  than they would have if caused by the impact of an asteroid

(D)  other volcanic eruptions were not occurring  at the same time as those in the Deccan region

(E) it is  not possible to determine which would have occurred first , the volcanic flows in the Decean region or the supposed impact of an asteroid

A. New theory says extinction had occurred due to volcano, therefore they must have assumed that volcano was
 
not caused by the impact of asteroid. Otherwise, if they don't assume this, it would be considered that main cause was ASTEROID

IMPACT and VOLCANIC ERUPTIONS was secondary complementary activity.

B,C, D, and E all are irrelevant in context.

vasuca10 · Answer

Hi  vikasp99

I would like to help you out with this question

Conclusion : A new competing theory contends that any asteroid impact was irrelevant.

Volcanic activity caused extinction of dinosaurs and other species and asteroid did not caused any kind of extinction of dinosaurs and other species

Premise : The Deccan region of India contains extensive volcanic flows that occurred within the same time period as the supposed asteroid impact and the extinctions.

Answer choice A is the correct answer choice as it eliminated linking of two theories and if we negate A it falsifies the conclusion that the impact of asteroids is irrelevant.

Now lets look at other answer choices as well

(B) no individual dinosaurs survived the impact of the asteroid, if it occurred - INCORRECT as even if some individual dinosaurs survived the impact of asteroid our conclusion is not impacted

(C) the extinctions took place over a longer time period than they would have if caused by the impact of an asteroid -  IRRELEVANT, time period is not what we are concerned with. Our main focus is cause of extinction of dinosaur whether asteroid impact or massive volcanic activity

(D) other volcanic eruptions were not occurring at the same time as those in the Decean region -  OUT OF SCOPE, other colcanic eruptions

(E) it is not possible to determine which would have occurred first, the volcanic flows in the Decean region or the supposed impact of an asteroid -  INCORRECT as timing of occurence is not what we are concerned with

David nguyen · Answer

A favored theory to explain the extinction of dinosaurs, together with many other species, has been the globally catastrophic collision of a large asteroid with the Earth. Supporting evidence is an extraterrestrial chemical element in a layer of dust found worldwide at a geological level laid down contemporaneously with the supported event. A new competing theory contends that any asteroid impact was irrelevant, because it was massive volcanic activity that caused the extinctions by putting enough dust into the atmosphere to cool the planet. The Deccan region of India contains extensive volcanic flows that occurred within the same time period as the supposed asteroid impact and the extinctions.

Logical Chain: 
A causes C ( Asteroids depleted dinosaurs)
No, B causes C (Volcano depleted dinosaurs

In order for this chain to whole true, A must have not caused B to happen and vice and versa.

The new theory assumes that

A was not caused by B. This matches our thought. Keep it.
 
This does not explain whether Volcano killed the dinosaurs. (B) is out.
 
Duration is irrelevant. We only need to know which one was the cause.
 
Other volcanic eruptions are irrelevant. The reasoning is only concerned with 1 massive volcano.
 
If both can't be determined so how did the author come to the conclusion? Non-sense. (E) is out

A is left. A is the answer.

unraveled · Answer

A favored theory to explain the extinction of dinosaurs, together with many other species, has been the globally catastrophic collision of a large asteroid with the Earth. Supporting evidence is an extraterrestrial chemical element in a layer of dust found worldwide at a geological level laid down contemporaneously with the supported event. A new competing theory contends that any asteroid impact was irrelevant, because it was massive volcanic activity that caused the extinctions by putting enough dust into the atmosphere to cool the planet. The Deccan region of India contains extensive volcanic flows that occurred within the same time period as the supposed asteroid impact and the extinctions.

The new theory assumes that

(A) the massive  volcanic activity was not caused by the impact of an asteroid  - CORRECT. POE helps. But the two events as discussed are supposed to be independent of each other. If not then things change and passage flow is disrupted. 
(B)  no individual dinosaurs survived  the impact of the asteroid, if it occurred - WRONG. There can be exceptions but this is at best irrelevant.
(C) the  extinctions took place over a longer time period than  they would have if caused by the impact of an asteroid - WRONG. Time period is irrelevant as we are seeking for the cause of the extinction and not a comparison.
(D)  other volcanic eruptions were not occurring  at the same time as those in the Decean region - WRONG. Does not let's us assess the cause of the extinction. Irrelevant.
(E) it is not possible to determine  which would have occurred first , the volcanic flows in the Decean region or the supposed impact of an asteroid - WRONG. Not which occurred first but which one caused the extinction is the question here.

Answer A.

FATT · Answer

(A) the massive volcanic activity was not caused by the impact of an asteroid

Applying negation to above we get - the massive volcanic activity  was caused  by impact of an asteroid

this breaks the new theory mentioned in passage which says the asteroid was irrelevant and it was the volcanic activity (Deccan) did the killing via atmospheric dust.

hence A

A favored theory to explain the extinction of dinosaurs, together with

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A favored theory to explain the extinction of dinosaurs, together with

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