Music historian: In the past, radio stations would not play rock songs that were more than three minutes in length. Rock musicians claimed that such commercial barriers limited their creativity, and some critics argue that only since those barriers have been lifted has rock music become artistic. In fact, however, when these barriers were lifted, the standards for song structures broke down and the music became aimless, because the styles from which rock derived were not well suited to songs of extended length.
Summary
Usually, radio stations do not play rock songs longer than three minutes. Rock musicians argue that this time constraint limited their creativity, and some critics argue that rock music has become artistic only because this time constraints have been lifted. However, song structures began to break down and music became aimless when the time constraints were lifted. This is because the styles that are the basis of rock music are not well suited for songs of extended length.
Strongly Supported Conclusions
In some cases, rock music can benefit from time constraints rather than be harmed by them.
A
Rock music is not a good outlet for creative musicians who have a great many ideas.
This answer is unsupported. To say that rock music is not a good outlet for creativity is too extreme. We only know rock musicians argue that time constraints limit creativity, not eliminate creativity entirely.
B
Rock music must borrow from styles more conducive to songs of extended length if it is to become artistic.
This answer is unsupported. To say that rock music must borrow from other styles is too extreme. We don’t know from the stimulus if there are any styles that are suited for songs of extended length.
C
Rock music requires more discipline than some other forms of music.
This answer is unsupported. We are not told anything about other forms of music in order to make this comparison.
D
Rock music can sometimes benefit from the existence of commercial barriers rather than being harmed by them.
This answer is strongly supported. We know from the stimulus that, after time constraints were lifted, song structures began to break down. Therefore, rock music benefited at least somewhat from the time constraints.
E
Rock music is best when it is made by musicians who do not think of themselves as being self-conscious artists.
This answer is unsupported. We don’t know from the stimulus under what circumstances rock music is the best.
In order for a fossil to serve as evidence that birds evolved from dinosaurs, it must be the case that the entire fossil is from a single animal.
But the recently discovered fossil is a compositive of bones collected from different parts of the discovery site.
To make the argument valid, then, we want to prove that the fossil is not from the same animal. We can do this by establishing that if the fossil is a composite from different areas of the discovery site, it must come from more than one animal.
A
The only paleontologists who believe that the entire fossil is from a single animal are those who were already convinced that birds evolved from dinosaurs.
B
If the fossil is a composite, then it has pieces of more than one animal.
C
There are other fossils that provide evidence that birds evolved from dinosaurs.
D
If the entire fossil is from a single animal, then it is a well-preserved specimen.
E
The fossil was stolen from the discovery site and sold by someone who cared much more about personal profit than about the accuracy of the fossil record.
Until recently it was widely believed that only a limited number of species could reproduce through parthenogenesis, reproduction by a female alone. But lately, as interest in the topic has increased, parthenogenesis has been found in a variety of unexpected cases, including sharks and Komodo dragons. So the number of species that can reproduce through parthenogenesis must be increasing.
Summarize Argument
The author concludes that the number of species that can reproduce through parthenogenesis must be increasing. She supports this by noting that, as interest in the topic has grown, parthenogenesis has been discovered in more unexpected species.
Identify and Describe Flaw
The author assumes that parthenogenesis is on the rise just because more cases have been discovered. She overlooks the possibility that these species may have always reproduced this way, and humans are just now aware of it. In other words, the lack of interest and knowledge about parthenogenesis in the past doesn't mean that it didn't occur before.
A
equates mere interest in a subject with real understanding of that subject
The author never assumes that people’s increased interest in parthenogenesis means that they really understand it. She just claims that more cases of parthenogenesis have been found since interest in it has increased.
B
takes for granted that because one thing follows another, the one must have been caused by the other
This is the cookie-cutter flaw of assuming that correlation proves causation. The author doesn’t draw a causal conclusion at all. She concludes that the number of species that use parthenogenesis is increasing, but she doesn’t say that increased interest caused this increase.
C
takes ignorance of the occurrence of something as conclusive evidence that it did not occur
The author assumes that humans’ ignorance of certain species’ ability to reproduce through parthenogenesis is evidence that they could not reproduce this way before. But it’s more likely that these species always reproduced this way, and humans are just now aware of it.
D
overlooks a crucial difference between two situations that the argument presents as being similar
This is describing a flawed analogy. The author doesn’t make this mistake. She doesn’t present two situations as being similar in the first place. Instead, she assumes that parthenogenesis is on the rise just because more cases have been discovered.
E
presumes that because research is new it is, on that basis alone, better than older research
The author never assumes that new research is better than old research. She points out that humans are aware of more cases of parthenogenesis than they were in the past. But her flaw is in the assumption that this increased knowledge means that parthenogenesis is on the rise.