Male bowerbirds construct elaborately decorated nests, or bowers. Basi

Question

Male bowerbirds construct elaborately decorated nests, or bowers. Basing their judgment on the fact that different local populations of bowerbirds of the same species build bowers that exhibit different building and decorative styles, researchers have concluded that the bowerbirdsâ€™ building styles are a culturally acquired, rather than a genetically transmitted, trait.

Which of the following, if true, would most strengthen the conclusion drawn by the researchers?

Which of the following, if true, would most strengthen the conclusion drawn by the researchers?

(A) There are more common characteristics than there are differences among the bowerbuilding styles of the local bowerbird population that has been studied most extensively.

(B) Young male bowerbirds are inept at bowerbuilding and apparently spend years watching their elders before becoming accomplished in the local bower style.

(C) The bowers of one species of bowerbird lack the towers and ornamentation characteristic of the bowers of most other species of bowerbird.

(D) Bowerbirds are found only in New Guinea and Australia, where local populations of the birds apparently seldom have contact with one another.

(E) It is well known that the song dialects of some songbirds are learned rather than transmitted genetically.

GMATNinja · Accepted Answer

A certain surfing GMAT tutor couldn't resist googling bowerbirds, and he discovered that male bowerbirds really do construct incredibly elaborate nests. Why? Just to impress the lady bowerbirds, apparently.

But as you already know, it's a terrible idea to let any of that outside information enter your mind at all. So back to the fun stuff: let's start by identifying the conclusion of the researchers, which is that "the bowerbirds' building styles are a culturally acquired, rather than a genetically transmitted, trait." In other words, those researchers conclude that bowerbirds are not born with those building styles. Instead, the birds must learn those building styles. Now let's think about the structure of the researchers' argument. How do they arrive at that conclusion? We know that male bowerbirds build elaborately decorated nests, which are called bowers. "Different local populations of bowerbirds of the same species build bowers that exhibit different building and decorative styles." - So the building/decorative styles vary among local groups of these birds. Based on this variation, researchers conclude that the building styles must be a learned ("culturally acquired") trait. After all, if the building styles were genetically transmitted, why wouldn't the different local groups all have similar building/decorative styles? Now we need to find an answer choice that most strengthens the researchers' conclusion, so use process of elimination: Notice that this choice only describes ONE local population (the one that has been studied most extensively). Within that group, there are more common characteristics than there are differences among bower-building styles. Those similar characteristics could have been culturally acquired within the group OR genetically transmitted. We can't tell either way, so choice (A) doesn't strengthen the conclusion. Eliminate this one. Young males have NO bower-building skills and must spend years watching their elders before becoming accomplished (highly skilled). This suggests that the young males must LEARN how to build bowers from their elders. If the skills were genetic transmitted, then the males would probably not need to watch and learn from their elders. Choice (B) suggests that the bowerbirds' building styles are culturally acquired (learned), which supports the conclusion. Hang on to this one. Pay close attention to the details here. Choice (C) compares one species of bowerbird to most other species of bowerbirds. The passage, on the other hand, is concerned with "different local populations of bowerbirds of the same species ." Thus, choice (C) has no bearing on the evidence in the passage or the conclusion. Eliminate (C). We already know that different local populations of bowerbirds of the same species build bowers that exhibit different building and decorative styles. Now we also know that those local populations probably don't have much contact with one another. This suggests that the groups probably don't learn much from one another (little "cultural acquisition" between groups). If the groups had LOTS of contact, that might weaken the conclusion--e.g. if the building styles are culturally acquired and the groups are in constant contact, then why would they have different styles? But choice (D) doesn't help us to understand the observed DIFFERENCES. Are those differences cultural acquired or is there some other explanation (i.e. a genetic explanation)? This information does not help support (or weaken) the conclusion and should be eliminated. Choice (E) does support the idea that learned (i.e. culturally acquired) traits DO exist among some songbirds. But are bowerbirds songbirds? Even if they are, are they one of the songbirds whose song dialects are learned rather than genetically transmitted? Choice (E) certainly doesn't hurt the conclusion. The conclusion is still possible given this new information, but, unlike choice (B), the new information does not do much to strengthen the given argument. Choice (B) is the best choice.

KarishmaB · Answer

Lots of different answers here so let's analyze this question:

Premises:

Male bowerbirds construct elaborately decorated bowers. 
Different local populations of bowerbirds of the same species build bowers that exhibit different building and decorative styles,

Conclusion: The bowerbirds' building styles are a culturally acquired, rather than a genetically transmitted, trait

We need to strengthen the conclusion.

A. There are more common characteristics than there are differences among the bowerbuilding styles of the local bowerbird population that has been studied most extensively.

This tells us that there are more similarities than differences. This doesn't strengthen our argument at all. If anything, it weakens it by implying that quite a bit could be genetically transmitted since there are more similarities.

B. Young male bowerbirds are inept at bowerbuilding and apparently spend years watching their elders before becoming accomplished in the local bower style.

If bower building were a genetically transmitted trait, young bowers would have known how to build. But they do not and instead they acquire the skill by watching elders. This strengthens our argument that bower building skill is culturally acquired. Correct.

C. The bowers of one species of bowerbird lack the towers and ornamentation characteristic of the bowers of most other species of bowerbird.

We are not comparing bowers of different species. We are talking about different local populations of the same species. Even if bower building were genetically transmitted, the genes of one species would be different from those of another so genetic transmission would be perfectly valid. Hence this option doesn't help us strengthen our argument that bower building is culturally acquired and not genetically transmitted.

D. Bowerbirds are found only in New Guinea and Australia, where local populations of the birds apparently seldom have contact with one another.

Whether they have contact or not doesn't matter. Whether they are in contact or no would have been useful to know if we were to show why there are similarities in bower building styles (Close contact with other populations could have been the reason for similarities) or if we were to prove that it is a genetically transmitted trait (far apart but similarities could have strengthened the case for genetic acquisition). The building styles are different so it doesn't matter how close or far apart the populations are.

E. It is well known that the song dialects of some songbirds are learned rather than transmitted genetically.
Out of scope.

Answer (B)

rt31 · Answer

I have two questions
a) what all can we pre-think before going to the ans choices
b) I was confused between B and D

pqhai · Answer

Hi rt31

I'm happy to help.

In strengthening question, you should  read the conclusion carefully . A correct answer should strengthen a conclusion by some ways. Please note that strengthening may vary from 1% to 100%. Let analyze the question.

ANALYZE THE STIMULUS: 
 
Fact 1: Male bowerbirds construct elaborately decorated nests, or bowers. 
Fact 2: Different local populations of bowerbirds of the same species build bowers that exhibit different building and decorative styles, 
Conclusion: researchers have concluded that the bowerbirds’ building styles are a culturally acquired, rather than a genetically transmitted, trait.

KEY word : “  culturally acquired,  NOT  genetically transmitted  ”. It means a bowerbird did not know how decorate a net at the time it was born. It has to learn how to decorate a net.

Question: Which of the following, if true, would most strengthen the conclusion drawn by the researchers?

ANALYZE EACH ANSWER: 
 
A. There are more common characteristics than there are differences among the bowerbuilding styles of the local bowerbird population that has been studied most extensively.
  Wrong.   Stick to key words above. Clearly, if the bowerbirds’ building styles are a genetically transmitted, there would be more common characteristics than there are differences among the bowerbuilding styles. Thus, A is wrong.

B. Young male bowerbirds are inept at bowerbuilding and apparently spend years watching their elders before becoming accomplished in the local bower style.
  Correct.   B clearly states the assumption of the conclusion. Bowerbird did not know how decorate a net at the time it was born. It has to learn how to decorate a net.

C. The bowers of one species of bowerbird lack the towers and ornamentation characteristic of the bowers of most other species of bowerbird.
  Wrong.   Out of scope.

D. Bowerbirds are found only in New Guinea and Australia, where local populations of the birds apparently seldom have contact with one another. 
  Wrong.   Let see an example: a bowerbird A is found in New Guinea; a bowerbird B is found in Australia; A and B have different bowerbirds’ building styles. But what if a bowerbird A’s building styles are acquired through genetic transmitted  from its parents . The same pattern is true for B. Clearly, it is possible that bowerbirds’ building styles are a genetically transmitted. Thus, D is wrong.

E. It is well known that the song dialects of some songbirds are learned rather than transmitted genetically.
  Wrong.   Out of scope.

Hope it helps.

RaviChandra · Answer

This is how I approach a CR Problem :

Premise : Different local populations of bowerbirds of the same species build different kind of nests.
Conclusion : So Researchers have concluded that the bowerbirds' building styles are a culturally acquired, rather than a genetically transmitted, trait

A Potential Answer For this question should ideally talk about

a) The Reason why the Styles are different(Supporting the point that they are not acquired genetically).

A. There are more common characteristics than there are differences among the bowerbuilding styles of the local bowerbird population that has been studied most extensively.
 
  This option says that the building Styles differ only slightly: This option is Neutral doesnt Really provide any information to support/Weaken the argument  
 
B. Young male bowerbirds are inept at bowerbuilding and apparently spend years watching their elders before becoming accomplished in the local bower style.
 
  This option Clearly says that these birds acquire this skill after they are born: By saying this it eliminates the possibility that the skill is genetically acquired:
 So strengthens 
 
C. The bowers of one species of bowerbird lack the towers and ornamentation characteristic of the bowers of most other species of bowerbird.
  The Argument is about Same Species bowerbirds So definitely out of scope 
 
D. Bowerbirds are found only in New Guinea and Australia, where local populations of the birds apparently seldom have contact with one another.
  Weakens the Conclusion

E. It is well known that the song dialects of some songbirds are learned rather than transmitted genetically. 
  Totally irrelevant

abhishekdadarwal2009 · Answer

Male bowerbirds construct elaborately decorated nests, or bowers. Basing their judgment on the fact that different local populations of bowerbirds of the same species build bowers that exhibit different building and decorative styles, researchers have concluded that the bowerbirdsâ€™ building styles are a culturally acquired, rather than a genetically transmitted, trait.

Which of the following, if true, would most strengthen the conclusion drawn by the researchers?

Which of the following, if true, would most strengthen the conclusion drawn by the researchers?

A. There are more common characteristics than there are differences among the bowerbuilding styles of the local bowerbird population that has been studied most extensively. 
This weakens the argument.
 B. Young male bowerbirds are inept at bowerbuilding and apparently spend years watching their elders before becoming accomplished in the local bower style. 
Correct answer because it supports the claim that the young bowerbirds do not know how to make the nests while they learn it by watching their elders and that's the only source of learning for them.
 C. The bowers of one species of bowerbird lack the towers and ornamentation characteristic of the bowers of most other species of bowerbird. 
This could be a supporting point for the given argument but this may also be due to the local availability of the resources and not just the bird's skills.
 D. Bowerbirds are found only in New Guinea and Australia, where local populations of the birds apparently seldom have contact with one another.
 
does not support the argument.
 E. It is well known that the song dialects of some songbirds are learned rather than transmitted genetically.  
song dialects is out of scope.

s8kadian · Answer

Male bowerbirds construct elaborately decorated nests, or bowers. Basing their judgment on the fact that different local populations of bowerbirds of the same species build bowers that exhibit different building and decorative styles, researchers have concluded that the bowerbirdsâ€™ building styles are a culturally acquired, rather than a genetically transmitted, trait.

Which of the following, if true, would most strengthen the conclusion drawn by the researchers?

Which of the following, if true, would most strengthen the conclusion drawn by the researchers?

A. There are more common characteristics than there are differences among the bower-building styles of the local bowerbird population that has been  studied  most extensively.
-  irrelevant

B. Young male bowerbirds are inept at bower-building and apparently spend years watching their elders before becoming accomplished in the local bower style. -  Correct

C. The bowers of one species of bowerbird lack the  towers and ornamentation  characteristic of the bowers of most other species of bowerbird.
-  irrelevant

D. Bowerbirds are found only in New Guinea and Australia, where local populations of the birds apparently  seldom have contact  with one another.
-  Weakens the argument

E. It is well known that the  song dialects  of some songbirds are learned rather than transmitted genetically. 
-  irrelevant

GmatDaddy · Answer

A. There are more common characteristics than there are differences among the bowerbuilding styles of the local bowerbird population that has been studied most extensively.
This shows nothing to prove that characateristics are culaturally acquired, even if they had been genetically acquired, there would be lesser differences than common  characteristics. Drop it.

B. Young male bowerbirds are inept at bowerbuilding and apparently spend years watching their elders before becoming accomplished in the local bower style.
 Had the characterisitcs transferred genetically, there would have been no need for bowerbirds to learn local bower style. Keep it.

C. The bowers of one species of bowerbird lack the towers and ornamentation characteristic of the bowers of most other species of bowerbird.
 Repeats the premise. Drop it.

D. Bowerbirds are found only in New Guinea and Australia, where local populations of the birds apparently seldom have contact with one another.
 Irrelevant. It does not affect our conclusion i any way. Drop it.

E. It is well known that the song dialects of some songbirds are learned rather than transmitted genetically.
 Irrelevant. Drop it.

Answer: B

kornn · Answer

Dear  AjiteshArun   DmitryFarber   IanStewart   MartyTargetTestPrep   VeritasPrepBrian   GMATNinja   GMATNinjaTwo   GMATGuruNY   AnthonyRitz  ,

I have some questions on choice D.

Q1. If local populations of the birds have LITTLE contact with one another and if the building styles are GENETICALLY acquired, then one would expect NO different building styles because the styles are in their blood! 
But the passage already says the building styles of the same species are different. So, the building styles should instead be CULTURALLY acquired.

It's like twins grown up in different geographic areas (i.e. in the jungle vs. in the city) have a different lifestyle and speak different language because of the  culture  differences around them. Like Tazan and his lost twin!

Why is my thinking wrong?

Q2. Choice D. is talking about the  same  species or  different  species of different local populations?

Q3. Why does the OE say this on choice D.?
 
The passage clearly provides that 
 
The explanation seems to contradict the passage.

GMATGuruNY · Answer

It is just as likely that each local species of bowerbird is genetically UNIQUE, resulting in a different building style for each local species.

Option D offers no information about species.

D offers no information about the number of species on each island.
It could be that local populations in New Guinea are all of the species, while those in Australia are of different species.

kornn · Answer

Dear  GMATGuruNY   VeritasKarishma ,

(D)  Bowerbirds are found only in New Guinea and Australia, where  local populations of the birds apparently seldom have contact with one another.

I have one question on the highlighted part. Does it refer to contact within the same island or the contact between the 2 islands -- i.e., between New Guinea and Australia?

GMATGuruNY · Answer

Conveyed meaning:
Each population in New Guinea has no contact with any other population in New Guinea.
Each population in Australia has no contact with any other population in Australia.

sgaaa · Answer

This is a CORRELATION vs. CAUSATION argument. Because building styles vary from location to location, the author concludes that the building styles are culturally acquired. The assumption is that genetically transmitted traits are not location-specific for this species of birds, and thus would not account for the difference. Option D states that local populations seldom have contact with one another. This would imply that they do not share cultural practice (supporting the argument), but it would equally support the contention that these groups might not share all genetically transmitted traits (weakening the argument).

VerbalBot · Answer

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Male bowerbirds construct elaborately decorated nests, or bowers. Basi

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