Passage - General Questions

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Passage Discussion

Paragraph One:

Most science passages begin by outlining some unexplained phenomenon or unresolved question, and this one is no exception. Here, the question is why the Calvaria major, a once-abundant tree found on the island of Mauritius, is now almost extinct. One ecologist, Stanley Temple, blames the dodo bird. He points to the unusual coincidence between the time the dodo bird became extinct and the age of the only surviving Calvaria major trees today, arguing that the extinction of the dodo bird prevented the tree from reproducing.

Paragraph Two:

The second paragraph elaborates on Temple’s hypothesis by describing exactly how the extinction of the dodo led to the scarcity of Calvaria major trees. His logic goes like this: The dodo used to eat the fruits of Calvaria major, as a result of which their pits evolved a thick wall meant to withstand the abrasive forces in the bird’s digestive tract. The seeds inside the pit could still germinate upon exit, because the abrasion caused thinning of the pit wall, but with the dodo now extinct these seeds get trapped inside the thick-walled pit. As a result, the seeds can no longer germinate.

Paragraph Three:

The third paragraph presents additional findings in support of Temple’s theory, but suggests that their credibility is somewhat suspect. Temple used other birds such as turkeys to determine whether the pits of the Calvaria major could have withstood the dodo’s digestive system, and found some evidence supporting his position. Nevertheless, the author describes Temple’s hypothesis as having only a “semblance of rigor” (lines 33-34), suggesting that a critique will follow in the next paragraph.

Paragraph Four:

The fourth paragraph indicates that Temple’s proposal is disputed by “leading specialists in the field” (lines 46-47), and introduces several arguments against it. One ecologist (Strahm) found evidence suggesting that Calvaria major seeds can germinate without the dodo’s help. Another expert (Speke) speculated that Calvaria major germination, though rare, is probably adequate enough to prevent the species from becoming extinct. The author accepts these findings as evidence that the population decline of the Calvaria major tree could have easily resulted from factors other than the extinction of the dodo bird. The last sentence of this paragraph summarizes the main point of the passage.

VIEWSTAMP Analysis

There are three viewpoints outlined in this passage: those of Temple, the leading specialists—including Strahm and Speke—and the author’s. The bulk of this passage discusses Temple’s hypothesis, which the leading specialists challenge in the fourth paragraph. The author implicitly agrees with the specialists’ position that the dodo was not necessary for the survival of Calvaria major, but her views are not explicitly stated until the fourth paragraph.

The Structure of the passage is as follows:

• Paragraph 1: Introduce Stanley Temple and his theory.
  
  Paragraph 2: Elaborate on the causal reasoning underlying Temple’s hypothesis.
  
  Paragraph 3: Describe additional findings supporting Temple’s position, but suggest that his argument may not be rigorous enough.
  
  Paragraph 4: Attack Temple’s hypothesis and summarize the main point of the passage.

The author’s Tone can most accurately be described as skeptical: she regards Temple’s hypothesis as initially plausible (line 45), but ultimately unconvincing (lines 46-62).

The passage presents two central Arguments. One of them is Temple’s, which attributes the present-day scarcity of Calvaria major trees to the disappearance of the dodo bird:

• Cause Effect
  V Temple: Dodo extinction Decline of Calvaria major

The counterargument is that of the author, who challenges Temple’s hypothesis by describing the recent findings of various experts in the field. Due to their explanatory potential, both Temple’s and the author’s arguments are inherently causal, as they present competing causes for the same effect.

The Main Point of the passage is that the scarcity of Calvaria major is probably due to factors other than the disappearance of the dodo bird, in spite of Temple’s claims to the contrary. The author alludes to her suspicion that Temple’s hypothesis is not credible in the third paragraph, but does not explicitly reject it until the very end of the passage. This passage structure severely penalizes test-takers who try to save time by skimming at the end, and is quite common in Reading Comprehension passages.

Purpose:

Broadly speaking, the purpose of the passage is to outline and reject a scientific hypothesis.

[lsat2016]

How can you conclude that the LSAT author is also disagreeing with the explanation? Is it because of paragraph 3?

In PT 77 passage 4, the author seems to dispute the evidence regarding Lamarckism but the main point question doesn't seem to reflect this because the author attributes the suspicion to other biologists. These two passages seem to have the same structure, yet the answer choice for this passage's main point question is much more stronger "is probably NOT due to the extinction of the dodo".

Thank you!!

[Adam Tyson]

The last paragraph certainly is an important part of the main point here, lsat2016, and makes clear that the author does not agree with Temple's conclusions, but there is evidence elsewhere in the passage that should suggest his doubts long before that point. The author said that Temple "assumed" the seeds could no longer germinate (line 14), and that sounds like our author thinks perhaps Temple was making a bad assumption. Shortly after that the author tells us that a "temporal coincidence" led Temple to a causal conclusion - in other words, the author is telling us that it IS just a coincidence, and that Temple is wrong. Later still, he says that Temple's arguments had "a semblance of rigor", and if that isn't a backhanded compliment I don't know what is! In other words, they weren't REALLY rigorous, but they looked that way to the casual observer.

Our author was sowing seeds of doubt throughout the early parts of the passage, which then germinated and grew in the final paragraph, where we learn that Temple was completely wrong about the number of trees and their ages and their ability to germinate. Experts in the field provide plenty of evidence of this.

The structure of the Lamarckism passage is actually very different than this one, and I would point you to that thread to see how:

lsat/viewforum.php?f=716

Basically, that passage is NOT about discrediting Lamarck, but about looking at how some recent studies might actually support some of Lamarck's ideas despite some possible alternate explanations and skepticism. Check out the discussion of that passage and you'll see the difference.