Biologist: In Region X, the average horn mass and body length of adult

Question

Biologist:  In Region X, the average horn mass and body length of adult bighorn sheep has dropped over the past several decades.  The cause is probably regulations prohibiting hunting of smaller animals. These regulations have undoubtedly given smaller sheep an advantage in surviving to a reproductive age. Therefore,  genes for smaller adult size most likely have spread through the population.

The two sections in  boldface  play which of the following roles in the biologist's argument?

A The first is the main conclusion; the second is an observation for which a causal explanation is presented.
B The first is a premise supporting the second; the second is the main conclusion, but not the only conclusion.
C The first describes a phenomenon for which the main conclusion presents an explanation; the second is a subsidiary conclusion supporting the main conclusion.
D The first is a subsidiary conclusion that supports the main conclusion; the second is a premise that independently supports the main conclusion.
E The first suggests a causal explanation for a phenomenon described by the main conclusion; the second provides further evidence to support that explanation.

MartyMurray · Accepted Answer

Explanation

Let's go through the passage and label the parts.

Part    Function      Biologist:   author      In Region X, the average horn mass and body length of adult bighorn sheep has dropped over the past several decades.    statement of fact     The cause is probably regulations prohibiting hunting of smaller animals.   main conclusion     These regulations have undoubtedly given smaller sheep an advantage in surviving to a reproductive age.   supporting information     Therefore,  genes for smaller adult size most likely have spread through the population.    intermediate conclusion

It's a little tricky to decide whether "The cause is probably regulations prohibiting hunting of smaller animals," or "Therefore,  genes for smaller adult size most likely have spread through the population, " is the main conclusion.

At the same time, by noticing that "These regulations have undoubtedly given smaller sheep an advantage in surviving to a reproductive age. Therefore,  genes for smaller adult size most likely have spread through the population, " supports "The cause is probably regulations prohibiting hunting of smaller animals," we can decide that "The cause is probably regulations prohibiting hunting of smaller animals," is the main conclusion since it is supported by other statements in the passage but does not support anything else.

A The first is the main conclusion; the second is an observation for which a causal explanation is presented.

We could argue that the second part of this choice is correct since, in a way, " genes for smaller adult size most likely have spread through the population, " is explained by "These regulations have undoubtedly given smaller sheep an advantage in surviving to a reproductive age."

However, this choice has a clear failure point in that the first statement is not a conclusion. It's just a fact about a phenomenon.

Eliminate.

B The first is a premise supporting the second; the second is the main conclusion, but not the only conclusion.

This choice is tricky because the second boldfaced portion could seem to be the main conclusion because it appears at the end of the passage and is preceded by "therefore." So, we could decide that the second boldfaced portion is the main conclusion and that the first boldfaced portion provides support since it's at the beginning of the passage.

However, as we discussed above, the second boldfaced portion is an intermediate conclusion rather than the main conclusion.

Also, the first boldfaced portion merely describes the situation and does not support the second.

Eliminate.

C The first describes a phenomenon for which the main conclusion presents an explanation; the second is a subsidiary conclusion supporting the main conclusion.

The first does describe a phenomenon for which the main conclusion, "The cause is probably regulations prohibiting hunting of smaller animals," presents an explanation.

Also, as we discussed above, the second is an intermediate, or subsidiary, conclusion that supports the main conclusion.

Keep

D The first is a subsidiary conclusion that supports the main conclusion; the second is a premise that independently supports the main conclusion.

This choice is almost completely incorrect since the first is not a subsidiary conclusion and does not support any conclusion and the second is an intermediate conclusion and thus does not support the main conclusion "independently." Rather, it supports the main conclusion by following from "These regulations have undoubtedly given smaller sheep an advantage in surviving to a reproductive age."

However, notice that the question-writer did make this choice a little tricky because the first part of this choice correctly describes the second boldfaced portion and because the second part of this choice is somewhat correct in that the second boldfaced portion does support the main conclusion. So, the question-writer made it possible that, if we're not careful, we could be tempted to choose this choice.

Eliminate.

E The first suggests a causal explanation for a phenomenon described by the main conclusion; the second provides further evidence to support that explanation.

This choice is incorrect. At the same time, it's interesting to see how the question writer made this choice tricky.

The first boldfaced portion is the phenomenon rather than the explanation for the phenomenon, but if we're not careful, we could see "phenomenon" in this choice and think that it correctly describes the first boldfaced portion.

Also, the second boldfaced portion does help to support the explanation.

So, this choice is a good example of an incorrect boldfaced answer choice that can trip us up if we fail to keep thing straight.

Eliminate.

Correct Answer   C

samarpan.g28 · Answer

In (C), "body length of adult bighorn sheep has dropped over the past several decades" is a phenomenon. "genes for smaller adult size most likely have spread through the population" is the subsidiary conclusion. The conclusion is "These regulations have undoubtedly given smaller sheep an advantage in surviving to a reproductive age". Therefore, option (C) is correct.

Engineer1 · Answer

MartyMurray  Great explanation! I did get this one right. However, I chose C by method of elimination.

Can both of you pease review my answer?  MartyMurray   KarishmaB  Thank you.

A.  the second is an observation for which a causal explanation is presented.   (Incorrect, second is an intermediate / subsidiary conclusion)
B.   The first is a premise supporting the second   (Incorrect, the first one is not a premise) 
D.  the second is a premise that independently supports the main conclusion   (Incorrect, the second one is not a premise either)
E.   the second provides further evidence to support that explanation    (Incorrect, the second one is not an evidence)
C.   the first describes a phenomenon for which the main conclusion presents an explanation; the second is a subsidiary conclusion supporting the main conclusion (Close enough.)

I thought that the first BF is the main conclusion.
"The cause is probably regulations prohibiting hunting of smaller animals" - sounded like the premise to the first BF
"These regulations have undoubtedly given smaller sheep an advantage in surviving to a reproductive age." - further premise.
2nd BF uses "Therefore", definitely a conclusion. In this case, it is an intermediate conclusion.

MartyMurray · Answer

Correct.
 
Correct.
 
Well, the second does provide support for the main conclusion.

However, it's not "a premise that independently supports the main conclusion" because it's an intermediate conclusion, rather than a statement of fact that stands on its own.
 
The second actually does support the explanation, even though the second is itself an intermediate conclusion.

So, what you said here isn't really correct.
 
This choice isn't just "close enough." It's spot on.
 
It's not though. It's a statement of fact about horn mass and body length.
 
This statement about the cause doesn't support the information about the mass and length. So, it's not a premise. We have to consider what supports what logically, rather than consider "sound."
 
This statement doesn't support the statement about the mass and length either.
 
This is correct.

ankit** · Answer

But It seems from the passage that 1st cause is described  and further upon analysis of the cause the author reaches a conculsion.
The conclusion reached is   genes for smaller adult size most likely have spread through the population.

How can we be sure that it is not the main conclusion of the passage
Please explain the gap in my understanding

SergejK · Answer

@  MartyMurray   Are you sure that "In Region X, the average horn mass and body length of adult bighorn sheep has dropped over the past several decades." is the main conclusion? I think it is rather: "These regulations have undoubtedly given smaller sheep an advantage in surviving to a reproductive age." as it is suggested here. It is not presented as supporting information but rather as the author's conclusion which for me is indicated throgh the word "undoubtedly". If we look if the sentence can function as a cause, we see that it actually can't. The other way around it works. These regulations have undoubtedly given smaller sheep an advantage in surviving to a reproductive age BECAUSE of regulations prohibiting hunting of smaller animals LEADING TO genes for smaller adult size spreading through the population.

I learned that explanations for one of the conclusions can never be the main conclusion, it is rather an intermediate conclusion supporting the main conclusion. I initially mistook the last sentence as the main conclusion because I didn't follow this process, therefore got the question wrong. But the process does not work for what you defined as the main conclusion, at least not for me. Would highly appreciate it if you could clear my doubts.

PS: But you seem to be correct regarding the cause-effect explanation from a prior question regarding identifying the conclusion. Considering this, and also the fact that "probably" was used, it is more likely that the sentence "The cause is probably regulations prohibiting hunting of smaller animals" is the main conclusion, for which the sentence directly after provides the explanation. I think comparing main conclusion with subsidiariy conclusions, cause-effect could help to identify the main conclusion. But according to my new understanding, the cause itself can also be a conclusion. Correct?

SergejK · Answer

Biologist:  In Region X, the average horn mass and body length of adult bighorn sheep has dropped over the past several decades . The cause is probably regulations prohibiting hunting of smaller animals. These regulations have undoubtedly given smaller sheep an advantage in surviving to a reproductive age. Therefore,  genes for smaller adult size most likely have spread through the population.

The two sections in boldface play which of the following roles in the biologist's argument?

A The first is the main conclusion; the second is an observation for which a causal explanation is presented.
B The first is a premise supporting the second; the second is the main conclusion, but not the only conclusion.
C The first describes a phenomenon for which the main conclusion presents an explanation; the second is a subsidiary conclusion supporting the main conclusion.
D The first is a subsidiary conclusion that supports the main conclusion; the second is a premise that independently supports the main conclusion.
E The first suggests a causal explanation for a phenomenon described by the main conclusion; the second provides further evidence to support that explanation.

I think I got it now:

We are dealing here with a 3-part conclusion.
1. The cause is probably regulations prohibiting hunting of smaller animals.
2. These regulations have undoubtedly given smaller sheep an advantage in surviving to a reproductive age.
3. Therefore, genes for smaller adult size most likely have spread through the population.
All 3 statements are based upon the premise in the first boldfaced part and are worded not like a premise but like an opinion.To decide which one is the main conclusion, I thought looking at what is his main point, what the biologists advocates for, could lead me to the main conclusion. And I decided for the strongest statement, which all the others must support. In my opinion, the word 'undoubtedly' similarly to 'clearly', sounds like the final conclusion that the biologist drew and the narrative he pushes. Also, when we have several separate conclusions, one can try the A because of B trick, with A being the main conclusion that is supported by B and in this case also C.  A  "These regulations have undoubtedly given smaller sheep an advantage in surviving to a reproductive age" because  B  "genes for smaller adult size most likely have spread through the population" caused by  C  " regulations prohibiting hunting of smaller animals." So the 2 intermediate conclusion clearly provide support for the main conclusion which is: "These regulations have undoubtedly given smaller sheep an advantage in surviving to a reproductive age". Also, 'therefore' can also function as a synonym for because so it's not always a main conclusion marker. Similarly to the first conclusion that clearly presents itself as a cause, which in itself cannot be the main conclusion.

So it is clear that first boldfaced part is the premise, so that we can eliminate A, D, and E, as A and D misidentify it as conclusion and E misidentifies it as causal explanation, which is incorrect as first boldbaces poses simply as premise without creating a causal link. Equally, we can decide against B as it suggests that first boldfaced supports the second, which is not the case. B is also incorrect as it misidentifies second boldfaced as the main conclusion. We are left with C, which is the correct answer choice.

A_Nishith · Answer

Argument Structure:
 First boldface:  "The cause is probably regulations prohibiting hunting of smaller animals."
This statement presents a causal explanation for the observed phenomenon (i.e., the reduction in average horn mass and body length of the sheep).
 Second boldface:  "Genes for smaller adult size most likely have spread through the population."
This statement is a subsidiary conclusion drawn from the causal explanation. It helps explain why the smaller sheep now have a reproductive advantage.

Reanalysis of Option C: 
The first describes a phenomenon for which the main conclusion presents an explanation; the second is a subsidiary conclusion supporting the main conclusion.
The first boldface indeed describes the phenomenon (regulations affecting the survival of smaller sheep) for which the overall argument (spread of smaller size genes) provides an explanation. This makes it part of the explanation process.
The second boldface is a subsidiary conclusion, supporting the main argument that the smaller sheep's genes are spreading.
 
Why C is Correct: 
The first boldface is not the ultimate conclusion but rather sets up the explanation (i.e., why smaller sheep survive and reproduce).
The second boldface serves as a subsidiary conclusion that provides further support for the main idea.

Conclusion:
Answer is C. The first boldface describes the phenomenon, and the second is a supporting conclusion.

JuniqueLid · Answer

Hi Marty, thanks for your explanations.

I found myself confused with the application of the "because" test to identify the main conclusion. I understand the principle idea of the "because" test is to see which conclusion candidate does not support any other premises - the part before "because" in a logically sound arrangement of the two statements should be the main conclusion.

In this question, applying the "because" test gives us:
1.  Genes for smaller adult size have spread through the population (Part A)  because  regulations prohibiting hunting of smaller animals (Part B) . >> Makeses logic senses. Therefore, B supports A. A should be the main conclusion.
2.  Regulations prohibited hunting of smaller animals (Part B)  because  genes for smaller adult size have spread (Part A) . >> Does not make sense. Therefoere, A does not support B. A should be the main conclusion.

This is clearly contradicting the OA and your reasoning. Could you, or someone else, please point out where I got it wrong?
PS: I think my application of the test is done correctly because using another example:”People should eat more vegitables because vegitables are full of vitamins." - here it is clear "people should eat more vegitables" (the part before the "because") is the conclusion.

Many thanks!

MartyMurray · Answer

Here's the issue.

What you've written above is not some support and a conclusion that follows from the support. Rather, it's two statements that present a description of a cause-effect relationship.

regulations prohibiting hunting of smaller animals  has CAUSED  Genes for smaller adult size have spread through the population

"Because" logically connects the statements because "because" has multiple meanings and uses.

In what you put together above, "because" is used to indicate that the second caused the first, similarly to how "because is used in the following sentence:

John is very good at public speaking because he has practiced a lot.

That sentence describes a situation in which practicing a lot has caused John to be good at public speaking.

Notice that, in the passage, the fact that there are  regulations prohibiting hunting of smaller animals  does not act as support for the idea that  genes for smaller adult size have spread through the population . In fact, there isn't a statement in the passage that says simply, "Genes for smaller adult size have spread through the population.

Rather, there is a different statement, the following:

The cause  is probably regulations prohibiting hunting of smaller animals.

That fact about "the cause" of the reduction in size of bighorn sheep does not support the idea that "genes for smaller adult size have probably spread through the population." Rather, it follows from that idea. In other words, that idea about genes is why it's believable that the cause of the reduction in size of bighorn sheep is regulations prohibiting hunting of smaller animals.

JuniqueLid · Answer

Thanks Marty, this is very clear and a brilliant explanation. Thank you for putting in your time clarifying.

KarishmaB · Answer

Here is a video explaining this somewhat tricky CR question:
 https://www.youtube.com/watch?v=0XVVkCCaEoE

kartickdey · Answer

This is a really a tricky question which enriches logical understanding.

Usernamevisible · Answer

What is the problem?

“size has dropped”

Your brain should ask:
WHY did size drop?

Which sentence answers that WHY?

“The cause is probably regulations...”

This is directly answering the question.
✔ So this = main conclusion

Step 3: Then what is this?
“genes for smaller size have spread”

Ask:
Is this answering why size dropped?
No

It’s explaining how the cause works

Super simple analogy
“People are getting fatter” (fact)
“Because of fast food” (main conclusion)
“Fast food has high calories” (support)

“high calories” sounds technical — but it’s NOT the main point

Final simplification
Main conclusion = WHY
Genes sentence = HOW the why works

One line to remember
 If you can say
“THIS is the reason for the phenomenon” → main conclusion

Only one sentence in the passage does that:
✔ “The cause is probably regulations”

Biologist: In Region X, the average horn mass and body length of adult

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Part	Function
Biologist:	author
In Region X, the average horn mass and body length of adult bighorn sheep has dropped over the past several decades.	statement of fact
The cause is probably regulations prohibiting hunting of smaller animals.	main conclusion
These regulations have undoubtedly given smaller sheep an advantage in surviving to a reproductive age.	supporting information
Therefore, genes for smaller adult size most likely have spread through the population.	intermediate conclusion

GMAT Critical Reasoning (CR) Questions

Biologist: In Region X, the average horn mass and body length of adult

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