Calvaria major is a rare but once-abundant tree found on the island of

Question

Calvaria major  is a rare but once-abundant tree found on the island of Mauritius, which was also home to the dodo, a large flightless bird that became extinct about three centuries ago. In 1977 Stanley Temple, an ecologist whose investigation of Calvaria major was a sidelight to his research on endangered birds of Mauritius, proposed that the population decline of Calvaria major was linked to the demise of the dodo, a hypothesis that subsequently gained considerable currency. Temple had found only thirteen Calvaria major trees on Mauritius, all overmature and dying, and all estimated by foresters at over 300 years old. These trees produced fruits that appeared fertile but that Temple assumed could no longer germinate, given his failure to find younger trees.

The temporal coincidence between the extinction of the dodo and what Temple considered the last evidence of natural germination of Calvaria major seeds led him to posit a causal connection. Specifically, he hypothesized that the fruit of Calvaria major had developed its extremely thick-walled pit as an evolutionary response to the dodo’s habitual consumption of those fruits, a trait enabling the pits to withstand the abrasive forces exerted on them in the birds’ digestive tracts. This defensive thickness, though, ultimately prevented the seeds within the pits from germinating without the thinning caused by abrasion in the dodo’s gizzard. What had once been adaptive, Temple maintained, became a lethal imprisonment for the seeds after the dodo vanished.

Although direct proof was unattainable, Temple did offer some additional findings in support of his hypothesis, which lent his argument a  semblance of rigor . From studies of other birds, he estimated the abrasive force generated within a dodo’s gizzard. Based on this estimate and on test results determining the crush-resistant strength of Calvaria major pits, he concluded that the pits could probably have withstood a cycle through a dodo’s gizzard. He also fed Calvaria major pits to turkeys, and though many of the pits were destroyed, ten emerged, abraded yet intact. Three of these sprouted when planted, which he saw as vindicating his hypothesis.

Though many scientists found this dramatic and intriguing hypothesis plausible, Temple’s proposals have been strongly challenged by leading specialists in the field. Where Temple had found only thirteen specimens of Calvaria major, Wendy Strahm, the foremost expert on the plant ecology of Mauritius, has identified hundreds, many far younger than three centuries. So Calvaria major seeds have in fact germinated, and the tree’s reproductive cycle has thus continued, since the dodo’s disappearance.

Additional counterevidence comes from horticultural research by Anthony Speke, which shows that while only a minority of unabraded Calvaria major seeds germinate, the number is still probably sufficient to keep this species from becoming extinct. The population decline, while clearly acute, could easily be due to other factors, including disease and damage done by certain nonindigenous animals introduced onto Mauritius in the past few centuries.    1 
 1. Which one of the following most accurately expresses the main point of the passage?

(A) Calvaria major germination, though rare, is probably adequate to avoid extinction of the species.
(B) The appeal of Temple’s hypothesis notwithstanding, the scarcity of Calvaria major is probably not due to the extinction of the dodo.
(C) Temple’s experimentation with Calvaria major pits, though methodologically unsound, nevertheless led to a probable solution to the mystery of the tree’s decline.
(D) Temple’s dramatic but speculative hypothesis, though presented without sufficient supporting research, may nevertheless be correct.
(E) Calvaria major would probably still be scarce today even if the dodo had not become extinct.

2 
 2. The author indicates that Temple’s research on birds of the island of Mauritius

(A) was largely concerned with species facing the threat of extinction
(B) furnished him with the basis for his highly accurate estimates of the crush-resistant strength of Calvaria major pits
(C) provided experimental evidence that some modern birds’ gizzards exert roughly the same amount of abrasive force on their contents as did dodo gizzards
(D) was comprehensive in scope and conducted with methodological precision
(E) was originally inspired by his observation that apparently fertile Calvaria major pits were nevertheless no longer able to germinate

3 
 3. In saying that Temple’s supporting evidence lent his argument a “semblance of rigor” ( Highlighted ), the author most likely intends to indicate that

(A) despite his attempts to use strict scientific methodology, Temple’s experimental findings regarding Calvaria major pits were not carefully derived and thus merely appeared to support his hypothesis
(B) direct proof of a hypothesis of the sort Temple was investigating is virtually impossible to obtain, even with the most exact measurements and observations
(C) in contrast to Temple’s secondhand information concerning the age of the thirteen overmature Calvaria major trees he found, his experiments with turkeys and other birds represented careful and accurate firsthand research
(D) in his experimentation on Calvaria major pits, Temple produced quantitative experimental results that superficially appeared to bolster the scientific credibility of his hypothesis
(E) although the consensus among experts is that Temple’s overall conclusion is mistaken, the scientific precision and the creativity of Temple’s experimentation remain admirable

4 
 4. The passage indicates which one of the following about the abrasion of Calvaria major pit walls?

(A) Thinning through abrasion is not necessary for germination of Calvaria major seeds.
(B) In Temple’s experiment, the abrasion caused by the digestive tracts of turkeys always released Calvaria major seeds, undamaged, from their hard coverings.
(C) Temple was mistaken in believing that the abrasion caused by dodos would have been sufficient to thin the pit walls to any significant degree.
(D) Abrasion of Calvaria major pit walls by the digestive tracts of animals occurred commonly in past centuries but rarely occurs in nature today.
(E) Temple overlooked the fact that other natural environmental forces have been abrading Calvaria major pit walls since the dodo ceased to fulfill this role.

5 
 5. It can be most logically inferred from the passage that the author regards Temple’s hypothesis that the extinction of the dodo was the cause of Calvaria major’s seeming loss of the ability to reproduce as which one of the following?

(A) essentially correct, but containing some inaccurate details
(B) initially implausible, but vindicated by his empirical findings
(C) an example of a valuable scientific achievement outside a researcher’s primary area of expertise
(D) laudable for its precise formulation and its attention to historical detail
(E) an attempt to explain a state of affairs that did not in fact exist

6 
 6. Based on the passage, it can be inferred that the author would be likely to agree with each of the following statements about Calvaria major EXCEPT:

(A) The causes of the evolution of the tree’s particularly durable pit wall have not been definitively identified by Temple’s critics.
(B) The notion that the thickness of the pit wall in the tree’s fruit has been a factor contributing to the decline of the tree has not been definitively discredited.
(C) In light of the current rate of germination of seeds of the species, it is surprising that the tree has not been abundant since the dodo’s disappearance.
(D) There is good reason to believe that the tree is not threatened with imminent extinction.
(E) Calvaria major seeds can germinate even if they do not first pass through a bird’s digestive system.

HarshaBujji · Accepted Answer

The overall Summary of the passage is as follows : Para 1 Summary: A proposal by an ecologist, Relation b/w 2 species on the occurrence of a phenomenon. Para 2 Summary: Yeah, Coincidence -> Hypothesis with some data.

Para 3 Summary: Yeah as expected, No solid proof but some findings to support… Not a foolproof theory

Para 4 It’s a sad ending

, where the author presents research that contradicts the ecologist's hypothesis. He gave 2 theories to counter the initial hypothesis. Overall Summary : Some coincidence ->Some Hypothesis -> Data/Findings to back it -> Finally data to counter the hypothesis. Main Point: The initial hypothesis that Calvaria's major extension occurred due to the dodo extinction of the ecologist is probably not correct, There are counterarguments for the initial hypothesis. (A) Calvaria major germination, though rare, is probably adequate to avoid extinction of the species. Opposite to the data in the passage. Nowhere in the passage this is mentioned (B) The appeal of Temple’s hypothesis notwithstanding, the scarcity of Calvaria major is probably not due to the extinction of the dodo. Hmm, Let's hold it as it talks about Temple’s hypothesis X (C) Temple’s experimentation with Calvaria major pits, though methodologically unsound, nevertheless led to a probable solution to the mystery of the tree’s decline. Yeah true, But not the main idea. Para 4 provides counter-arguments which are missed in this idea. (D) Temple’s dramatic but speculative hypothesis, though presented without sufficient supporting research, may nevertheless be correct. Temple hypothesis is questioned in the passage, hence option is against the Main point (E) Calvaria major would probably still be scarce today even if the dodo had not become extinct. Hmm, Some relation b/w CM and Dodo.. Seems to be correct in 1st go Now we are left with B & E (B versus E is a tricky battle. One can easily overlook and mark E. B) The appeal of Temple’s hypothesis notwithstanding, the scarcity of Calvaria major is probably not due to the extinction of the dodo. Yeah Hypothesis not not 100% correct, The use of probably makes it a perfect choice. This is the instant of the final para and the main point E) Calvaria major would probably still be scarce today even if the dodo had not become extinct. We can say that dodo's extinction didn't cause CM's scarcity.But we can say that the vice-versa be true. IMO B. Eg: If dodo is not extinct then CM generation/reproduction could be way more the the new ext. factor that is causing the degrowth

Sajjad1994 · Answer

Explanation

2. The author indicates that Temple’s research on birds of the island of Mauritius

Difficulty Level:   700

Explanation

The correct answer will be a statement within the passage text.

A.  Yes.   In  line 6   (Calvaria major was a sidelight to his research on endangered birds of Mauritius) , the passage state’s that Temple’s focus was endangered birds.

B. No.  This answer choice is extreme. The author does not contend that Temple’s tests were  “highly accurate.”

C. No.  While Temple did tests with turkeys, there is not a contention that the turkey’s gizzard exerted the same abrasive force.

D. No.  The passage does not go into any detail about Temple’s bird research.

E. No.  The passage states that the research into Calvaria major was a  “sidelight”  to Temple’s bird research.

Answer: A

Sajjad1994 · Answer

Explanation

4. The passage indicates which one of the following about the abrasion of Calvaria major pit walls?

Difficulty Level:   700

Explanation

The correct answer will be a statement within the passage text.

A.  Yes.   This is supported at the end of the fourth paragraph. The passage states that a minority of unabraded seeds germinate.

B. No.  This is contradicted by the third paragraph.

C. No.  The author does not dispute the contention that abrasion by the dodos could have thinned the pit walls.

D. No.  There is no support for a claim about how often abrasion happened.

E. No.  There is do discussion of other causes of abrasion.

Answer: A

Sajjad1994 · Answer

Explanation

6. Based on the passage, it can be inferred that the author would be likely to agree with each of the following statements about Calvaria major EXCEPT:

Difficulty Level:   700

Explanation

Four of the answer choices will be consistent with or supported by the text and the credited response will not.

A. No.  This is consistent with the passage. The paragraph about the critics does not discuss the evolution of the durable pit wall.

B. No.  This is consistent with the passage. The critics do not address the thickness of the pit wall.

C.  Yes.   The passage discusses that there is acute population decline due to a variety of potential factors.

D. No.  This is consistent with the passage. The passage states that the current rate of germination is probably sufficient to keep the species from becoming extinct.

E. No.  This is consistent with the passage. The last paragraph indicates that unabraded seeds can sprout.

Answer: C

Sajjad1994 · Answer

Explanation

3. In saying that Temple’s supporting evidence lent his argument a “semblance of rigor” (Highlighted), the author most likely intends to indicate that

Difficulty Level:   700

Explanation

The credited response will be consistent with what the author says about Temple’s research.

A. No.  The author concludes that Temple’s hypothesis is likely incorrect based on the research of others, rather than a lack of strict methodology on Temple’s part.

B. No.  The author is indicating possible validity of Temple’s research in spite of a lack of direct proof.

C. No.  The author does not compare the sources of information regarding the trees and birds.

D.  Yes.   The author is arguing that this research lent credibility to Temple’s hypothesis.

E. No.  The passage does not indicate what the consensus of experts is.

Answer: D

Sajjad1994 · Answer

Explanation

5. It can be most logically inferred from the passage that the author regards Temple’s hypothesis that the extinction of the dodo was the cause of Calvaria major’s seeming loss of the ability to reproduce as which one of the following?

Difficulty Level:   700

Explanation

The credited response will be consistent with what the author says about Temple’s research.

A. No.  The author concludes that Temple is likely incorrect.

B. No.  The author concludes that Temple is likely incorrect.

C. No.  The author does not claim that Temple’s research is a valuable scientific achievement.

D. No.  The author does not discuss Temple’s precision and ultimately casts doubt on his conclusion.

E.  Yes.   The author concludes that Temple’s hypothesis is likely incorrect.

Answer: E

Sajjad1994 · Answer

Explanation

1. Which one of the following most accurately expresses the main point of the passage?

Difficulty Level:   700

Explanation

Use your Bottom Line of the passage to help you to evaluate the choices. The correct answer will describe the author’s overall point.

A. No.  This choice does not mention Temple’s hypothesis.

B.  Yes.   This is a good paraphrase of the Bottom Line.

C. No.  The author neither accuses Temple of being methodologically unsound, nor does he or she concur with Temple.

D. No.  The author concludes that Temple is probably incorrect.

E. No.  The passage does not discuss this hypothetical.

Answer: C

Alka10 · Answer

Thanks  Sajjad1994  , I had gone through the soln, however, my doubt is different -

IN the passage, we have contradicting statements present for this ans choice, I rejected it on the basis of statement given in 1 below:

1.  Para 2 - Line 9 - Temple's hypothesis  : This defensive thickness, though, ultimately prevented the seeds within the pits from germinating without the thinning caused by abrasion in the dodo’s gizzard. -   It states germinating without thinning by abrasion was not witnessed.

2.  Last para first line -  Additional counterevidence comes from horticultural research by Anthony Speke, which shows that while only a minority of unabraded Calvaria major seeds germinate, the number is still probably sufficient to keep this species from becoming extinct. -   It states germinating was witnessed even without abrasion.

So, I had rejected this choice on the basis of temple's hypothesis, so in such questions which evidence should we consider to mark our ans?

Thanks
Alka

Sajjad1994 · Answer

While Temple's hypothesis suggests that the thinning caused by abrasion in the dodo's gizzard was necessary for the germination of Calvaria major seeds, the subsequent information presents a different perspective.

The evidence from the passage that supports the answer can be found in the  last paragraph , where it is mentioned that  "Wendy Strahm, the foremost expert on the plant ecology of Mauritius, has identified hundreds, many far younger than three centuries."  This statement indicates that Calvaria major seeds have indeed germinated and that the tree's reproductive cycle has continued even after the disappearance of the dodo. This finding contradicts Temple's hypothesis, suggesting that thinning through abrasion is not necessary for the germination of Calvaria major seeds.

While Temple's hypothesis seemed plausible based on his observations, the subsequent data from Wendy Strahm's research directly contradicts his assumption. The fact that many younger trees have been identified and the species' reproductive cycle has continued without the presence of dodos indicates that seed germination can occur without the thinning caused by dodos' gizzards.

The other pieces of evidence provided in the passage, such as Temple's experiments with turkeys and Anthony Speke's horticultural research, also contribute to the overall understanding that seed germination can occur without the specific abrasion caused by dodos. These findings collectively lead to the conclusion that answer  choice (A)  is the most accurate interpretation of the evidence provided in the passage.

Calvaria major is a rare but once-abundant tree found on the island of

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Calvaria major is a rare but once-abundant tree found on the island of

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