Like Charles Darwin, Alfred Wegener revolutionized an entire science.

Question

Like Charles Darwin, Alfred Wegener revolutionized an entire science. Unlike Darwin’s ideas, which still stir up much controversy, Wegener’s theory of drifting continents is accepted almost without question, but it did not succeed without a struggle.

In 1912 Wegener suggested that Africa and South America are estranged pieces of a single, ancient supercontinent, Pangaea, that had drifted apart, leaving the Atlantic Ocean between them. However, even Wegener believed that geological wear and tear over the ages would have damaged the fine detail of ancient coastlines, destroying the best evidence for drift. He never tested the fit between African and South American coastlines with any exactitude, and for a time his ideas were  virtually ignored . In 1924 Harold Jeffreys, who would become one of the strongest critics of the theory, dismissed it in his landmark book  The Earth . Apparently after casually observing the shorelines on a globe, Jeffreys concluded that the fit between Africa and South America was  very poor .

Disturbed by Jeffreys’ obviously perfunctory  observation, S. W. Carey used  careful techniques  of geometric proportion to correct, better than most maps do, for the fact that the continents’ margins lie on a sphere rather than on a flat surface. He found a remarkably close fit. At about the same time, Keith Runcorn found other evidence for drift. When volcanic lava cools and hardens into basalt, it is magnetized by the earth’s own magnetic field. The rock’s poles become aligned with the earth’s magnetic poles. Though the Planet’s poles have wandered over the past few hundred million years, the magnetic field of each basalt garment is still aligned the way the earth’s poles were at the rime the rock was formed. Although one would expect that the magnetic fields of rocks of the same age from any continent would all be aligned the same way the earth’s magnetic field was aligned at that time, the magnetic fields of basalts in North America are now aligned quite differently from rocks formed in the same epoch in Europe. Thus, the rocks provided clear evidence that the continents had drifted with respect to each other. True to form, Jeffreys brusquely rejected Runcorn’s studies. His casual disdain for such observational data led some field geologists to suggest that his classic should be retitled  An Earth .

In 1966 compelling proof that the seafloor spreads from the midocean ridges confirmed the hypothesis that molten rock wells up at these ridges from deep within the earth and repaves the seafloor as giant crustal plates move apart. Thus, seafloor spreading not only explained the long-standing puzzle of why the ocean basins are so much younger than the continents, but also provided evidence that the plates, and so the continents on them, move. Overnight, plate tectonic theory, with continental drift, became the  consensus view.    1 
 1) Which of the following best expresses the main idea of the passage?

(A) Confirmation of Wegener’s theory of continental drift came from unexpected sources.
(B) Critics of Wegener’s theory of continental drift provided information that contributed to its final acceptance
(C) The history of the theory of continental drift is similar in a number of ways to the history of Darwin’s most important theory.
(D) Though Wegener’s theory of continental drift is now generally accepted, Wegener himself was unable to provide any evidence of its accuracy.
(E) Though Wegener’s theory of continental drift had significant implications, many years and much effort were required to win its acceptance.

2 
 2. Jeffreys’ approach to Wegener’s theory is most like the approach of which one of the following?

(A) a botanist who concludes that two species are unrelated based on superficial examination of their appearance
(B) a driver who attempts to find a street in an unfamiliar city without a map
(C) a zoologist who studies animal behavior rather than anatomy
(D) a politician who bases the decision to run for office on the findings of a public opinion poll
(E) a psychiatrist who bases treatment decisions on patients’ past histories

3 
 3. According to the passage, evidence of seafloor spreading helped to explain which one of the following?

(A) the reason for the existence of the giant crustal plates on which the continents are found
(B) the reason basalts retain their magnetic field alignments
(C) the reason the earth’s poles have wandered
(D) the composition of the giant crustal plates on which the continents are found
(E) the disparity between the age of the continents and that of the ocean basins

4 
 4. Which one of the following phrases, as used in context, most clearly reveals the author’s opinion about Jeffreys?

(A) “virtually ignored”
(B) “very poor”
(C) “obviously perfunctory”
(D) “careful techniques”
(E) “consensus view”

5 
 5. The author’s mention of the fact that some field geologists suggested calling Jeffreys’ work  An Earth  serves to

(A) contrast two of Jeffreys’ ideas
(B) justify criticisms of Jeffreys’ work
(C) emphasize an opinion of Jeffreys’ work
(D) explain the reasons for Jeffreys’ conflict with Wegener
(E) support an assertion about Jeffreys’ crticis

6 
 6. It can be inferred that Carey believed Jeffreys’ 1924 appraisal to be

(A) authoritative and supported by indirect evidence
(B) obvious but in need of interpretation
(C) accurate but in need of validation
(D) unquestionably based on insufficient research
(E) so deficient as to be unworthy of investigation

7 
 7. The information in the passage suggests that which one of the following findings would most clearly undermine evidence for the theory of continental drift?

(A) It is discovered that the ocean basins are actually older than the continents
(B) New techniques of geometric projection are discovered that make much more accurate mapping possible
(C) It is determined that the magnetic fields of some basalts magnetized in Europe and North America during the twentieth century have the same magnetic field alignment
(D) It is found that the magnetic fields of some contemporaneous basalts in Africa and South America have different magnetic fields
(E) It is determined that Jeffreys had performed careful observational studies of geological phenomena
 A

auradediligodo · Accepted Answer

Hi,

took me 17 minutes of which 6 minutes for reading, making paragraphs summaries and main point formulation. Got 7/7 correct.

P1:Proving W'theory was not easy
P2: present W'theory and critics from J
P3: K and R's theories in opposition to J's theory
P4: How W's theory was fully explained through seafloor spreading

MP: present W's theory along with opposing, supporting views and an explanation for the theory

1)  Which of the following best expresses the main idea of the passage?

prethinking:  refer to the main point formulation above

(A) Confirmation of Wegener’s theory of continental drift came from unexpected sources.  the seafloor spreading evidence is not unexpected. plus the confirmation of W's theory is only related to last paragraph 
(B) Critics of Wegener’s theory of continental drift provided information that contributed to its final acceptance  here the critics are represented by J who does not provide any evidence in support of W's theory 
(C) The history of the theory of continental drift is similar in a number of ways to the history of Darwin’s most important theory.  it is not similar, hence incorrect 
(D) Though Wegener’s theory of continental drift is now generally accepted, Wegener himself was unable to provide any evidence of its accuracy.  in P2it is written that W was puzzled about his theory but the passage is not only about this! Hence incorrect 
(E) Though Wegener’s theory of continental drift had significant implications, many years and much effort were required to win its acceptance.  yes. even tough it is not worded exactly as our MP there are some similarities.

2.  Jeffreys’ approach to Wegener’s theory is most like the approach of which one of the following?

Pre-thinking:  refer to P2. I would say that Jeffrey approach is superficial and not willing to evaluate other options

(A) a botanist who concludes that two species are unrelated based on superficial examination of their appearance  Yes. In P2 it is written that just because he could not see a perfect match between south america and Africa he rejected the validity of W's theory  
(B) a driver who attempts to find a street in an unfamiliar city without a map  in this AC we lack of two elements of comparisons and the superficial behaviour 
(C) a zoologist who studies animal behavior rather than anatomy  this AC would suggest that J studied a different topic which is not true... hence incorrect  
(D) a politician who bases the decision to run for office on the findings of a public opinion poll  this behavior seems rational and based on a detailed research. this behavior just doesn't match with J's 
(E) a psychiatrist who bases treatment decisions on patients’ past histories  Jeffrey doesn't base his judgement on past proof. hence incorrect

3 . According to the passage, evidence of seafloor spreading helped to explain which one of the following?

Prethinking:  refer to the last paragraph here."seafloor spreading not only explained the long-standing puzzle of  why the ocean basins are so much younger than the continents , but also provided evidence that the  plates, and so the continents on them, move . Any Answer choice along the lines of the underlined portion of the passage should work

(A) the reason for the existence of the giant crustal plates on which the continents are found  incorrect 
(B) the reason basalts retain their magnetic field alignments  incorrect 
(C) the reason the earth’s poles have wandered  incorrect 
(D) the composition of the giant crustal plates on which the continents are found  incorrect 
(E) the disparity between the age of the continents and that of the ocean basins  yes and in line with our prethinking

Please note that most of the other answer choices were either out of context or inconsistent here

4.  Which one of the following phrases, as used in context, most clearly reveals the author’s opinion about Jeffreys?

Pre-thinking: For this question refer to the end of P2 and the beginning of P3. J is considered as extremely superficial and not willing to evaluate other options

(A) “virtually ignored”  it was not ignored as for the beginning of P2 
(B) “very poor”  Not poor but superficial 
(C) “obviously perfunctory”  perfunctory is the same word used in P2 
(D) “careful techniques”  out of context here. careful techniques refer to C 
(E) “consensus view”  also out of context. consensus view refers to another theory

5 . The author’s mention of the fact that some field geologists suggested calling Jeffreys’ work An Earth serves to

Pre-thinking: An earth is used to denote: "His casual disdain for such observational data.". It seems that other scientists see his work as something describing another planet and as something based on some interpretations that don't seem really convincing

(A) contrast two of Jeffreys’ ideas  the title itself does not contrast with J's ideas. Incorrect 
(B) justify criticisms of Jeffreys’ work  again the title itself can't justify anything of the sort. Incorrect 
(C) emphasize an opinion of Jeffreys’ work  this is very close because the scientists who refer to J's work think that his work is based on observations that are not really well researched. So according to them J's work is no more than an opinion, IE not based on sure proofs. Also pay attention to the use of the article "an": it implies that there could be other earths (=opinion) 
(D) explain the reasons for Jeffreys’ conflict with Wegener  the title can not really convey this idea just by itslef 
(E) support an assertion about Jeffreys’ crticis  again not in line with the scientists view on J

6 . It can be inferred that Carey believed Jeffreys’ 1924 appraisal to be

Pre-thinking:refer to the beginning of P2: according to this portion C is disturbed by the extremely superficial behavior of J

(A) authoritative and supported by indirect evidence  J's work is not authoritative and no indirect evidence is cited 
(B) obvious but in need of interpretation   obviously  C believes that J'theory is wrong 
(C) accurate but in need of validation  quite opposite here 
(D) unquestionably based on insufficient research  yes as any superficial work might be. Correct 
(E) so deficient as to be unworthy of investigation  although J'theory s considered generally wrong it is never classified as deficient or unworthy of investigation. As a Matter o fact C is so disturbed that he works on his theory to disprove J's

7 . The information in the passage suggests that which one of the following findings would most clearly undermine evidence for the theory of continental drift?

Pre-Thinking:  In order to undermine a theory it is important to know what is the evidence that confirms the theory. So refer to the last paragraph and to the outcomes of the research of seafloor spreading. Two results come out of it: #1:ocean basins are so much younger than the continents. #2:the plates, and so the continents on them, move. Now try to weaken these two facts

(A) It is discovered that the ocean basins are actually older than the continents  in line with our prethinking and hence correct 
(B) New techniques of geometric projection are discovered that make much more accurate mapping possible  this would not undermine the theory as for the fact that mapping is insufficient evidence anyhow 
(C) It is determined that the magnetic fields of some basalts magnetized in Europe and North America during the twentieth century have the same magnetic field alignment  I'd say wrong here because it talks about sediments which are contemporary whether the analysis in the passage talks about older sediments 
(D) It is found that the magnetic fields of some contemporaneous basalts in Africa and South America have different magnetic fields  again the contemporary issue here 
(E) It is determined that Jeffreys had performed careful observational studies of geological phenomena  J made his conclusions just by observing maps so whether he made accurate geological studies is not of our concern

RusskiyLev · Answer

Please could you explain, why in the question 1 answer B is wrong?

Thanks.

generis · Answer

RusskiyLev  , sure.

The passage mentions only one critic of Wegener's theory, Harold Jeffreys.

He does not provide evidence that supports Wegener's theory.
In fact, in addition to providing zero evidence in support of the theory, Jeffrey's dismisses Wegener's theory—twice.

The first time that Jeffreys dismissed the theory, he took a careless look at a map and decided that South America and Africa did not appear to fit very well together (as puzzle pieces might).

The second time that Jeffreys dismissed the theory, a  supporter  of Wegener, Keith Runcorn,  had  discovered compelling evidence of continental drift:
 True to form, Jeffreys brusquely rejected Runcorn’s studies. His casual disdain for such observational data led some field geologists to suggest that his classic should be retitled An Earth.  (Para 3)

The critic, Jeffreys, did not provide  any  information that led to the acceptance of Wegener's theory.

If I am missing something, please tag me and let me know.

Hope that helps.

RusskiyLev · Answer

generis ,

Thank you for the explanation. My main problem was the wrong interpretation of the word "critic". I thought that it is not only the person who gives a back feedback about the work of another author, but also people who justify it and bring some positive feedback on the work. So, I was thinking that it was not only Jeffries, but also Carey and Runcorn.

generis · Answer

RusskiyLev  , now I understand: you were thinking of the second meaning of the word "critic."

In North America and the UK, that second meaning is used routinely only in one area, namely, the arts, especially the fine arts and film. 
"Art critic" and "film critic" are neutral, with connotations that match the way you understood the word.

Reviewer  of any kind, in any area, is neutral.

On the GMAT, as far as I recall, when we see "critic" in a passage about science,  especially  when scientists or scholars have opposing views of a person's work, a  critic  is someone who disagrees with or is hostile towards the person's work.

this source  does so:  supporter, adherent, devotee, praiser, enthusiast,  and  apologist  are antonyms of critic that we might see on the GMAT. I don't know much about that source. In this case, it's accurate.]

Kumar Utkarsh · Answer

hi, 
D-incorrect as nowehere it is mentioned in passage about the wegner's effort to prove his theory so we don't know if he did or didn't have any proof
E- Correct as it is clear from the last line of first para. Implications are the effects it had directly or indirectly on other studies and researches.

zoezhuyan · Answer

I cannot get this quesiton, anyone can help ?

as the sentence from passage,i did not figure that It seems that other scientists see his work as something describing another planet and as something based on some interpretations that don't seem really convincing

auradediligodo · Answer

I'm happy to help here

Scientists in general think about Jeffrey as a superficial person that even when presented with good and reasonable evidence doesn't change his ideas and sticks with his beliefs. So when scientists look at his work they don't believe it is credible and based on concrete facts because they believe in facts, proofs and evidence. Hence it is reasonable to say that they believe Jeffrey's work to be much of an opinion rather than something supported by proof, evidence and facts. Hope this helps!

hero_with_1000_faces · Answer

Hey  auradediligodo  hope you are doing great.

I think "C" is incorrect because of the presence of  some . without "some" it would be a strong contender.

Refer the correct passage area here

Dhruv1212 · Answer

Can someone explain answer 5

Posted from my mobile device

Sajjad1994 · Answer

Explanation

5. The author’s mention of the fact that some field geologists suggested calling Jeffreys’ work An Earth serves to

Difficulty Level:   Vary Hard

Explanation

The author's mention of the fact that some field geologists suggested calling Jeffreys' work  "An Earth"  serves to emphasize an opinion of Jeffreys' work. The phrase  "An Earth"  is likely intended as a sarcastic play on words, suggesting that Jeffreys' work was more focused on theoretical ideas about the Earth rather than being grounded in observational data. This sarcastic suggestion highlights the author's perspective that Jeffreys was dismissive of observational data, as indicated by his casual disdain for evidence such as Runcorn's studies on the alignment of magnetic fields in rocks.

Option (A)  is incorrect because the passage does not contrast two of Jeffreys' ideas; rather, it discusses Jeffreys' dismissal of Wegener's theory and Runcorn's studies.

Option (B)  is not the primary purpose of mentioning the suggestion to rename Jeffreys' work. The mention serves to emphasize an opinion but not necessarily to justify criticisms of Jeffreys' work.

Option (D)  is incorrect because the passage does not provide information about Jeffreys' conflict with Wegener. It mainly focuses on Jeffreys' dismissal of Wegener's theory and Runcorn's studies.

Option (E)  is not the primary purpose of mentioning the suggestion to rename Jeffreys' work. The mention serves to emphasize an opinion but not specifically to support an assertion about Jeffreys' criticisms.

Answer: C

SmileAndSolve · Answer

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Like Charles Darwin, Alfred Wegener revolutionized an entire science.

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Like Charles Darwin, Alfred Wegener revolutionized an entire science.

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615 to 715 in 15 Days (Ria's Strategies)

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