Sign up to star your favorites LSAT 142 - Section 4 - Question 10
January 10, 2015In 2005, paleontologist Mary Schweitzer made headlines when she reported finding preserved soft tissue in the bones of a Tyrannosaurus rex dinosaur. Analysis of the collagen proteins from the T. rex showed them to be similar to the collagen proteins in modern-day chickens. Schweitzer’s discovery therefore adds to the mountain of evidence that dinosaurs are closely related to birds.
Summarize Argument
The author concludes that dinosaurs are closely related to birds. This is due to, among other evidence, a paleontologist’s discovery: that T. rex had collagen proteins similar to those found in modern chickens.
Notable Assumptions
The author assumes that dinosaurs and chickens having similar collagen proteins adds to the evidence that dinosaurs and birds are similar. This means the author believes such collagen proteins aren’t common to a whole host of totally unrelated animals. This also means he believes two dissimilar animals won’t share collagen proteins.
A
How rare is it to find preserved soft tissue in the bones of a dinosaur?
Irrelevant. Whether it’s very rare or very common to find soft tissue in dinosaur bones tells us nothing about the author’s argument: that collagen proteins in dinosaurs tells us dinosaurs are closely related to birds.
B
Is there any evidence at all against the claim that dinosaurs are closely related to birds?
The author never claims that all evidence points to dinosaurs and birds being closely related. He simply claims that shared collagens adds to the “mountain of evidence” that dinosaurs and birds are related.
C
How likely is it for animals that are not closely related to each other to have similar collagen proteins?
If it’s highly likely for animals that aren’t closely related to share collagens, then shared collagens between dinosaurs and chickens wouldn’t signify a close relation—a weakener. If it’s highly unlikely, then collagens likely do signify a close relation—a strengthener.
D
Is it possible that T. rex is more closely related to modern-day chickens than to certain other types of dinosaurs?
Irrelevant. Even if it were “possible,” that wouldn’t tell us that dinosaurs and birds are in fact closely related.
E
Before Schweitzer’s discovery, did researchers suppose that the collagen proteins in T. rex and chickens might be similar?
We don’t care what researchers had hypothesized before this discovery. We’re interested in if the study constitutes evidence that dinosaurs and birds are closely related.
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October 31, 2014Sign up to star your favorites LSAT 141 - Section 4 - Question 10
October 31, 2014Vacuum cleaner salesperson: To prove that this Super XL vacuum cleaner is better than your old vacuum cleaner, I ran your old vacuum once over this dirty carpet. Then I ran the Super XL over the same area. All that dirt that the Super XL picked up is dirt your old vacuum left behind, proving the Super XL is the better vacuum.
Summarize Argument
The salesperson concludes that the Super XL is the better vacuum because it picked up dirt that the old vacuum missed after both were used on the same area of carpet. The Super XL was used second.
Identify and Describe Flaw
The salesperson's argument is vulnerable to criticism because the vacuums weren't tested under the same conditions. Just because the Super XL picked up some dirt that the old vacuum missed doesn't necessarily suggest that the Super XL is better. In fact, the Super XL might have missed just as much dirt if it had been used first. The salesperson should have tested both vacuums individually to compare how much dirt they each collected on their first pass over equally dirty areas of carpet.
A
ignores the possibility that dirt remained in the carpet even after the Super XL had been used in the test
The salesperson never assumes that the Super XL picked up all the dirt in the carpet. Presumably at least a little bit of dirt remained in the carpet after the Super XL was used, but this doesn't change the fact that it picked up dirt that the old vacuum left behind.
B
takes for granted that the Super XL will still perform better than the old vacuum cleaner when it is the same age as the old vacuum cleaner
The salesperson argues that the Super XL is the better vacuum right now. He never assumes that it will still perform better in 10 years.
C
takes for granted that because the Super XL outperforms one vacuum cleaner it is the best vacuum cleaner available
The salesperson never claimed that the Super XL is the best vacuum cleaner available, just that it’s better than the old vacuum.
D
ignores the possibility that the amount of dirt removed in the test by the old vacuum cleaner is greater than the amount of dirt removed by the Super XL
The salesperson’s argument isn’t about which vacuum picked up the greater amount of dirt. He never actually assumes that the Super XL picked up more dirt. Instead, he argues that the Super XL is better because it picked up dirt that the old vacuum left behind.
E
ignores the possibility that if the Super XL had been used first it would have left behind just as much dirt as did the old vacuum cleaner
The salesperson didn’t test the vacuums under the same conditions. He argues that the Super XL is better because it picked up dirt that the old vacuum missed on its first pass. But it’s possible that the Super XL might’ve left behind just as much dirt if it had been tested first.
Sign up to star your favorites LSAT 73 - Section 2 - Question 10
October 31, 2014Sign up to star your favorites LSAT 141 - Section 2 - Question 10
October 31, 2014In Brecht’s plays, the audiences and actors find it difficult to discern any of the characters’ personalities.
In order to be a successful drama, audiences must care what happens to at least some of the characters.
The other premise tells us that audiences/actors find it difficult to discern characters’ personalities in Brecht’s plays. If we can show that this difficulty in discerning characters’ personalities implies that audiences won’t care about the characters, that would provide the missing link.
A
An audience that cannot readily discern a character’s personality will not take any interest in that character.
B
A character’s personality is determined primarily by the motives and beliefs of that character.
C
The extent to which a play succeeds as a drama is directly proportional to the extent to which the play’s audiences care about its characters.
D
If the personalities of a play’s characters are not readily discernible by the actors playing the roles, then those personalities are not readily discernible by the play’s audience.
E
All plays that, unlike Brecht’s plays, have characters with whom audiences empathize succeed as dramas.
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July 25, 2014