The golden toad of Costa Rica, whose beauty and rarity inspired

Question

The golden toad of Costa Rica, whose beauty and rarity inspired an unusual degree of human interest from a public generally unconcerned about amphibians, may have been driven to extinction by human activity nevertheless. In the United States, a public relations campaign featuring the toad raised money to purchase and protect the toad’s habitat in Costa Rica, establishing the Monteverde Cloud Forest Preserve in 1972. Although this action seemed to secure the toad’s future, it is now apparent that setting aside habitat was not enough to save this beautiful creature. The toad’s demise in the late 1980s was a harbinger of further species extinction in Costa Rica. Since that time, another twenty of the fifty species of frogs and toads known to once inhabit a 30 square kilometer area near Monteverde have disappeared.

The unexplained, relatively sudden disappearance of amphibians in Costa Rica is not a unique story. Populations of frogs, toads, and salamanders have declined or disappeared the world over. Scientists hypothesize that the more subtle effects of human activities on the world’s ecosystems, such as the build-up of pollutants, the decrease in atmospheric ozone, and changing weather patterns due to global warming, are beginning to take their toll. Perhaps amphibians—whose permeable skin makes them sensitive to environmental changes—are the “canary in the coal mine,” giving us early notification of the deterioration of our environment. If amphibians are the biological harbingers of environmental problems, humans would be wise to heed their warning.   1 
 1. According to the passage, all of the following are true EXCEPT:

(A) Humans are at least partially responsible for changing weather patterns.
(B) Toads, like frogs, have permeable skin.
(C) Human activity is not necessarily responsible for the global decline of amphibious populations.
(D) Costa Rica’s Monteverde Cloud Forest Preserve was not paid for solely by the Costa Rican government.
(E) More frog and toad species than salamander species have disappeared in Costa Rica since the late 1980s.

2 
 2. It can be inferred from the passage that

(A) only thirty species of frogs and toads remain in Costa Rica
(B) humans do not have permeable skin
(C) the build-up of pollutants in the atmosphere causes a decrease in atmospheric ozone
(D) humans do not usually take signals of environmental deterioration seriously
(E) Costa Rica suffers from more serious environmental problems than many other countries

3 
 3. The author uses the adjective “subtle” in the second paragraph most probably to emphasize that

(A) these effects are not easily recognized by sophisticated testing equipment
(B) these effects are difficult to notice because they take place over time on a global scale
(C) these effects are so minimal that they affect only small animal species such as amphibians
(D) these slight effects of human activity are rarely discussed by scientists
(E) these effects are infrequently observed because they affect only specific world regions

4 
 4. The passage implies that

(A) many amphibians are not considered beautiful.
(B) the Monteverde Cloud Forest Preserve was not large enough to protect the golden toad.
(C)) only Costa Rican amphibians living near Monteverde have disappeared since the 1980s.
(D) amphibians sometimes live in coal mines.
(E) no humans yet consider the decline of amphibious populations an indication of a threat to human populations.

5 
 5. The primary purpose of the passage is to

(A) discuss the mysterious disappearance of Costa Rica’s golden toad.
(B) explain why human activity is undoubtedly to blame for the global decline of amphibious populations
(C) convince humans that they must minimize the global output of pollutants.
(D) describe the recent global decline of amphibious populations and hypothesize about its causes.
(E) urge humans to pay careful attention to important environmental changes.

6 
 6. Which of the following best describes the overall organization of the passage?

(A) The first paragraph speculates on the causes of a global phenomenon; the second paragraph describes one specific example of this phenomenon.
(B) The first paragraph explains one environmental consequence of human activity; the second paragraph discusses solutions which might mitigate further environmental damage.
(C) The first paragraph details one instance of an ecological change; the second paragraph discusses the import and global extent of this change.
(D) The first paragraph discusses efforts to protect the habitat of a particular species; the second paragraph advocates for additional habitat protection.
(E) The first paragraph describes the unexplained worldwide disappearance of toads; the second paragraph adds that salamanders and frogs are also disappearing.

7 
 7. The passage implies that

(A) the Monteverde area may be home to toad or frog species that have not yet been noted by researchers
(B) the Monteverde Cloud Forest Preserve was not large enough to protect the golden toad
(C) only Costa Rican amphibians living near Monteverde have disappeared since the 1980s
(D) if amphibians did not have permeable skin, then they could not act as biological harbingers
(E) more than one third of the world’s amphibian species have become extinct

8 
 8. It can be inferred from the discussion of amphibians that

(A) only thirty species of frogs and toads remain in Costa Rica
(B) relatively few non-amphibious animals have permeable skin 
(C) most have either already become extinct or are in danger of extinction
(D) humans do not usually take signals of environmental deterioration seriously
(E) the extinction of so many amphibian species supports the contention that humans are responsible for the situation

Carcass · Accepted Answer

Official Explanation:

1. "Except" questions require us to test the five answer choices to determine the "odd one out." It is beneficial to use the True / False technique: label each answer choice with a T or an F and look for the odd one out (which, in this case, we should expect to be an F).

(A) True. The third sentence of the second paragraph characterizes changing weather patterns due to global warming as a subtle effect of human activities.

(B) True. The first two sentences of the second paragraph classify both toads and frogs as amphibians. Later in the second paragraph, the passage explains that amphibians have permeable skin.

(C) True. The third sentence of the second paragraph states explicitly that scientists “hypothesize” that human activity is responsible for the global decline of amphibious populations. Since a hypothesis is an educated guess rather than a fact, it is true that human activity may not be responsible for the decline.

(D) True. The second sentence of the first paragraph states that money was raised in the United States to establish the Monteverde Cloud Forest Preserve.

(E) CORRECT. False. The passage offers no information about the number of salamander species in Costa Rica that have disappeared since the late 1980s. We cannot assume that this omission indicates a lesser number than either toad or frog species.

2. The correct answer to an inference question on the GMAT must be supported by evidence from the text without need for external information.

(A) The passage states that twenty of the fifty species of frogs and toads known to once inhabit a 30-square-kilometer area near Monteverde have disappeared.

Nothing is implied about the areas of Costa Rica farther from Monteverde.

(B) CORRECT. The passage suggests that amphibians are able to offer humans early notification of the deterioration of the environment because of the amphibians’ permeable skin. Thus, permeable skin must be a characteristic that humans do not possess.

(C) No causal relationship between the build-up of pollutants in the atmosphere and a decrease in atmospheric ozone is suggested in the passage.

(D) The author states that humans would be wise to heed the warning offered by the decline of amphibious populations, but nothing suggests that humans normally do not take signals of environmental deterioration seriously.

(E) The passage does not compare Costa Rica’s environmental problems to those of other countries.

3. In the second paragraph, the author mentions “the more subtle effects of human activity on the world's ecosystems,” and then lists three of these effects: the build-up of pollutants, the decrease in atmospheric ozone, and changing weather patterns due to global warming, all of which, scientists hypothesize, “are beginning to take their toll.” The key to answering this question correctly is to recognize, in context, what these effects have in common.

(A) Nowhere does the passage suggest or imply that these changes are not easily recognized by sophisticated testing equipment.

(B) CORRECT. All of these effects happen on a global scale, so their immediate consequences on specific ecosystems are difficult to recognize. Furthermore, the passage states these effects are “beginning to take their toll,” indicating that the effects happen over time.

(C) Scientists hypothesize that these effects do affect amphibians, but nothing in the passage indicates that only small animal species such as amphibians are affected.

In fact, the final sentence of the passage indicates that humans too might be affected by these environmental changes.

(D) The passage states that scientists hypothesize about the consequences of these subtle effects; this indicates that scientists do in fact discuss these effects.

(E) The passage indicates that the consequences of these effects are global, causing disruptions in amphibious populations “the world over.”

4. This question is really just a disguised inference question. The correct answer to an inference question must be directly supported by evidence from the text.

(A) CORRECT. The first sentence of the passage states that the beauty of Costa Rica’s golden toad was one factor that generated interest from a public normally unconcerned with amphibians. Thus, many amphibians must not be considered beautiful.

(B) The passage indicates that habitat preservation in isolation - no matter the size of the habitat - was not enough to save the golden toad. Instead, scientists theorize that broader ecological issues are harming the world’s amphibious populations.

(C) The second paragraph tells us that amphibian populations have been declining around the world.

(D) This is a misinterpretation of the analogy used in the second paragraph. The author is implying that amphibians may provide humans an early warning for detrimental changes to the environment, just as canaries provide humans an indication of detrimental conditions in coal mines.

(E) The final sentence of the passage indicates that humans would be wise to recognize the potential environmental deterioration signified by declining amphibious population, but it is too extreme to infer that no humans consider this decline a threat to humans. In fact, the author of the passage seems to consider it a threat!

5. The first paragraph of the passage discusses a specific case in which a particular amphibian mysteriously disappeared from its habitat and suggests that humans may have been in some way responsible for its demise. The second paragraph explains that declining amphibious populations are actually a global trend and hypothesizes that a variety of human activities are harming these environmentally sensitive animals.

(A) The example of the golden toad is too narrow and specific to be the primary purpose of the passage. Instead, the golden toad is used as an example of a much larger trend.

(B) Though this answer choice is on the right track, it is too extreme to say that human activity is “undoubtedly” to blame for the global decline of amphibian populations. Instead the passage indicates that scientists “hypothesize” that human activity is responsible.

(C) An attempt to convince humans to minimize the output of pollutants is never mentioned in the passage.

(D) CORRECT. The passage discusses the mysterious disappearance of amphibious populations worldwide and hypothesizes that subtle effects on ecosystems resulting from human activity may be responsible for these disappearances.

(E) The final sentence of the passage does urge humans to pay attention to declining amphibian populations, but this is not the primary purpose of the passage. Moreover, the passage specifically discusses amphibians, while this answer choice broadly mentions “important environmental changes” rather than focusing on amphibians.

Bharath99 · Answer

Hi,

he word implies indicates that this is an inference question. The correct answer will not be stated explicitly in the passage; nevertheless, the information must be true according to information given somewhere in the passage. Wrong answers will often go “too far,” asserting something that might be plausible in the real world but is not directly supported by any specific information given in the passage.

(A) CORRECT. The last sentence of the first paragraph says that a certain proportion of the species of frogs and toads known to once inhabit an area near Monteverde have disappeared. The language known to indicates that the author is hedging: a total of fifty species are known to live there, but others might exist that have not yet been found or formally catalogued.

(B) The passage says only that preserving the habitat was not enough to save the species. The passage does not indicate why—whether this was related to size or some other factor.

(C) The first sentence of the second paragraph indicates that amphibian populations have been declining around the world.

(D) The last sentence of the second paragraph suggests that amphibians might be biological harbingers and implies that the quality of permeable skin has something to do with this designation. The passage does not indicate, though, that permeable skin is the only possible way in which amphibians could be considered harbingers. There might be other reasons or qualities that would still allow amphibians to be designated in this way.

(E) The beginning of the second paragraph indicates that between one third and one half of the world’s amphibian species have declined or disappeared. A decline is not the same thing as extinction; it is possible that less than one third have become extinct and the rest have merely declined.

Kinjo17 · Answer

Please your help with Q7:

7. The passage implies that
A) the Monteverde area may be home to toad or frog species that have not yet been noted by researchers
B) the Monteverde Cloud Forest Preserve was not large enough to protect the golden toad
C) only Costa Rican amphibians living near Monteverde have disappeared since the 1980s
D) if amphibians did not have permeable skin, then they could not act as biological harbingers
E) more than one third of the world’s amphibian species have become extinct

How can A be correct? The passage says:

"Since that time, another twenty of the fifty species of frogs and toads known to once inhabit a 30 square kilometer area  near  Monteverde have disappeared".

It doesn't say that it was actually in the Monteverde area. Probably the Monteverde area was much more studied that the surrounding areas, so the existence of unknowned frogs and toads near Monteverde doesn't imply that there are unknowned frogs inside Monteverde. I know frogs and toads can move, but if I think like that, I would be considering that Monteverde is surrounded by no limits or by limits which frogs and toads can trespass, which we don't know.

prags1989 · Answer

for que 8 - author has no where mentioned about Permeable skin of non-amphibians, then why B is right ?

XyLan · Answer

8. It can be inferred from the discussion of amphibians that 
Inference Qs in RC are  masterstrokes  by GMAT, as the test taker needs to be  decisively  precise and accurate.

Answer choice analysis:  
  
Excerpt from the passage: 
  Since that time, another twenty of the fifty species of frogs and toads  KNOWN  to once inhabit a 30 square kilometer area  near Monteverde  have disappeared.

The passage talks about the specis  near Monteverde .
Moreover, 20 out of 50  KNOWN  species have disappeared.
Does that imply that ONLY 30 species live in Costa Rica.
 No.  Cannot  say with 100% confidence. However, had the statement been -  ONLY 30 KNOWN species live  - It would have made sense. 
 Look at this way  -  
Statement says: The scientists have found 30 KNOWN species in Iceland.
Does it imply that ONLY 30 species live in Iceland?
 No.  Cannot  say with 100% confidence because there is STILL possibility of OTHER species, which are NOT found yet.  
  - It's Dicey -----> OUT   
   -I accept that B is an interesting answer choice. However, the other answer choices contain a SURESHOT error. Thus, by PoE, B is the champ!

Excerpt from the passage:
  The unexplained, relatively sudden disappearance of amphibians in Costa Rica is not a unique story.  Populations  of frogs, toads, and salamanders have declined or disappeared the world over.   The passage asserts ONLY about the different   populations  .
A really STRONG claim.  CANNOT  substantiate that more than  50%  of the species have either already become  extinct  or are in  danger of extinction .

Excerpt from the passage:
  If amphibians are the biological harbingers of environmental problems, humans would be wise to heed their warning. 
 In the last line, the author suggests that humans SHOULD heed to those warnings. Whether they do is  NOWHERE  discussed in the passage,  let alone seriously.

Excerpt from the passage:
  Scientists  hypothesize  that the more subtle effects of human activities on the world’s ecosystems, such as the build-up of pollutants, the decrease in atmospheric ozone, and changing weather patterns due to global warming, are beginning to take their toll.  
It's a mere  hypothesis .  CANNOT  say with 100% confidence.
  - It's Dicey -----> OUT

Harsh2111s · Answer

MentorTutoring   AjiteshArun   VeritasKarishma

In above explanation for option A "the Monteverde area may be home to toad or frog species  that have not yet been noted by researchers ".
The last sentence of the first paragraph says that a certain proportion of the species of frogs and toads known to once inhabit an area near Monteverde have disappeared.

How we can say that it is not noted by researchers yet ?
It seems researcher already knew this.

Kindly help.

Harsh2111s · Answer

carcass  -The above explanation for Q1 is most absurd way to present.

How can you assume two opposite things from single statement ?

MentorTutoring   AjiteshArun   VeritasKarishma 
Dear experts,
Can you explain how A and C can be true at same time or the question itself is wrong ?

AndrewN · Answer

Hello,  Harsh2111s . I had to look over that question twice before the process of elimination led me to (A). The line you paraphrased above, relative to answer (A), has a dual meaning. How about we look at the actual line and answer choice before we tease out the two interpretations?

Passage :  Since that time, another twenty of the fifty species of frogs and toads known to once inhabit a 30 square kilometer area near Monteverde have disappeared .

Answer : (A) the Monteverde area may be home to toad or frog species that have not yet been noted by researchers

Interpretation #1 : Researchers have not been able to locate thirty of the fifty species of frogs and toads once known to inhabit the area, so it is true that, at present, the area may, in fact, house more species, some of which may not have been documented in many years. Since the search for these species is ongoing,  not yet been noted  is qualified.

Interpretation #2 : Researchers had at one point in time  noted  the thirty missing species, so  not yet been noted  is unqualified, period.

Your line of thought traced path #2, and I will admit that my mind went in that direction at first, too. However, when I was able to disprove the other answers, I reexamined (A) and saw that the first interpretation is just as valid. This was a tricky question, but it can be used to illustrate why you should not settle on an answer you know you can disprove when another answer just makes you uncertain. Choice (A), despite its ambiguity, is the best of the lot.

I hope that helps. If you have further questions, feel free to ask.

- Andrew

AndrewN · Answer

Hello again,  Harsh2111s . If anything, this question underlines the importance of reading over each answer choice, time permitting. As soon as I reached (E), I thought,  Eureka!  To answer your question, though, I agree that choices (A) and (C) are mutually exclusive, and, furthermore, that (A) is the more problematic of the two. Whatever the source of the question may be, I propose a tweak for (A) to make it justifiable:

(A) Humans  may be  at least partially responsible for changing weather patterns.

This way, the definitive cause-and-effect relationship no longer holds, and choices (A) and (C) can both be supported by the passage. A hypothesis, indeed, is not an accepted fact. If you chose (A), I would suggest only that you read the other answer choices, since (E) is complete speculation and is the obvious candidate for the exception.

- Andrew

KarishmaB · Answer

Option (A) is correct because of the use of the word "may". Had it said "the Monteverde area is home to toad or frog species that have not yet been noted by researchers", it would be incorrect because it is not implied by the passage.
'May' adds uncertainty and as long as the passage doesn't say "there are no unknown species", the sentence with 'may' is true.

When you say 'there are 50 known species of frogs", you are implying that there MAY be some unknown species too.

The only relevant part of the sentence you mentioned is this: 
Since that time, another twenty of the  fifty species of frogs and toads known  to once inhabit a 30 square kilometer area near Monteverde have disappeared.

Perhaps there were/are some unknown species too.

KarishmaB · Answer

Yes, (A) and (C) both can be true at the same time. Read that one critical sentence carefully.

"Scientists hypothesize that the more subtle effects of human activities on the world’s ecosystems, such as the build-up of pollutants, the decrease in atmospheric ozone, and changing weather patterns due to global warming, are beginning to take their toll."

Scientists hypothesise - so this is a hypothesis, NOT an established fact.
What is the hypothesis? That the more subtle effects of human activities are beginning to take their toll.

Hence, (C) is true: Human activity is not necessarily responsible for the global decline of amphibious populations.

What are the human activities that we are talking about? the build-up of pollutants, the decrease in atmospheric ozone, and changing weather patterns due to global warming
The passage tells us that these are human activities - that weather patterns are changing due to global warming (due to human activity) - this is not a hypothesis

Hence (A) is correct: Humans are at least partially responsible for changing weather patterns.

(A) and (C) are different implications from the same sentence and both hold.

AndrewN · Answer

I see the point you are making,  VeritasKarishma , and I hold your views in high regard. At the same time, I believe a dual interpretation of the sentence in question still holds, namely the following:

1) The hypothesis resolves, exactly as you have outlined above:  the more subtle effects of human activities are beginning to take their toll . The examples following  such as  are  established   effects of human activities .

2) The hypothesis never resolves, but encompasses the entire sentence, examples and all. That is, scientists are  hypothesizing  that human activities,  such as...  A, B, and C,  are beginning to take their toll .

The structure of the sentence does not direct me to one interpretation or the other. I still advocate choice (E) as the clearcut exception, but I have read and considered the sentence from the passage quite carefully, and, as I have outlined above, I feel as though the evidence justifying choice (A) is ambiguous.

Thank you for your response. You are an asset to the community, I think everyone would agree.

- Andrew

jabhatta2 · Answer

GMATNinja ,  SajjadAhmad ,  GMATNinjaTwo ,  bm2201

Follow-up on question 6

While i understand why A / B /D and E are wrong -- i don't understand how C can be right

One word threw me off in choice C , That is the word "import"

I thought of this as  importing  of an idea.

Nowhere in the passage is there any discussion on "importing" or "import" of any idea or hypothesis (from Costa Rica i presume)

Please let us know your thoughts on the word "import"

bM22 · Answer

Hi  jabhatta@umail.iu.edu ,

I'll share, what I think import here means.
Import in literal terms means bringing in something, could be goods, thoughts or some changes. Import depending on the sentence can also be used for indicating something or showing significance of something. Here is mostly used in " changes brought about " context.

Now purpose of 2nd para: explanation using hypothesis as to what could have caused the unexplained sudden disappearance of amphibians in Costa Rica, implying that it discusses  what brought on this change  and what is the global extent of the same.

Let me know if this helps.
Thanks.

HansJK · Answer

This strikes my as a type of answer that would most often be correct: if amphibians did not have permeable skin, then they could not act as biological harbingers (7d). Because it stood out to me, I jumped the gun and did not see the better alternative, a. Am i correct in thinking that this sort of choice would most often be the correct answer? Thank you!!

MBAB123 · Answer

Hey HansJK , I made the same mistake as you. I hardly spent 20 seconds on the question and picked D. However, I now realise why D is wrong and it has nothing to do with option A. See if my this helps - Having permeable skin makes the bio harbingers, but is that the only feature that would make something a bio harbinger? We can't say for sure. It's just one of the features that makes a specie a bio harbinger. There may or may not be more features that do so. If a similar question came up in CR, I would have definitely ruled out D for assuming that permeable skin is the only feature that makes a specie a bio harbinger. The skill set needed for each of the 3 verbal sections definitely overlaps and more evidently so in the 700 level questions. I hope I can realise this more often than not.

VerbalBot · Answer

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