"Surprising" Phenomenon
Why do scientists expect crop yields to decrease when the crops seem to thrive in a warmer and wetter climate?
Objective
Any hypothesis that resolves this paradox must explain why crop yields are expected to decrease over the coming century. It may be a consequence of a climate that is consistently warmer and more humid, or it may be unrelated to climate.
A
Crop yields in southern Asia are expected to remain constant even after the average daily temperature and humidity there increase from recent levels.
This is information about southern Asia, not northern Asia. Rather than resolve the paradox, this states that the paradox does not exist in a different region.
B
Any increases in temperature and humidity would be accompanied by higher levels of atmospheric carbon dioxide, which is vital to plant respiration.
This deepens the paradox by implying a warmer, more humid climate should result in greater crop yields. If plants rely on carbon dioxide to grow, and the impending changes will result in more carbon dioxide in the atmosphere, then crops should benefit.
C
The climate in northern Asia has generally been too cool and dry in recent years for populations of many crop insect pests to become established.
This is a reason to expect crop yields will decrease. A consistently warm and humid climate will benefit pests, which over the long term may cause damage to crops that outweighs the potential benefits of a changing climate.
D
In many parts of Asia, the increased annual precipitation that would result from warmer and wetter climates would cause most edible plant species to flourish.
This deepens the paradox by further implying the changes in climate should cause crop yields to increase, not decrease. If a warmer, more humid climate causes edible plants to flourish, crops should not be expected to suffer.
E
The recent climate of northern Asia prevents many crops from being farmed there during the winter.
This does not explain why crop yields are expected to decrease over the next century. If changes in climate happen to allow more winter farming, that would be expected to increase yields, not diminish them.
Summarize Argument
The author concludes that Jones is the best qualified, because none of the other candidates has the same set of qualifications as Jones.
Identify and Describe Flaw
The conclusion is that Jones is the best qualified, but the support is merely that she has different qualifications from the other candidates. What makes her unique set of qualifications better than anyone else’s qualifications? The author doesn’t say, so his argument fails to provide evidence that supports the comparison made in the conclusion.
Moreover, the author notes that everyone has a unique set of qualifications. So the reason for choosing Jones—unique qualifications—equally applies to every other candidate. The argument singles out one member of a set based on a trait held by all members of that set.
A
uses flattery to win over those who hold an opposing position
No opposing position is identified. And although the author notes that Jones is the “best qualified,” nothing suggests that this is flattery—rather, this is simply the author’s conclusion about who the best candidate is.
B
refutes a distorted version of an opposing position
No opposing position is identified or refuted.
C
seeks to distinguish one member of a group on the basis of something that applies to all
The author tries to distinguish Jones as the best candidate on the basis of something—unique qualifications—that applies to all candidates. This is a flaw; if all candidates, like Jones, have unique qualifications, then we’re given no reason to choose Jones over anyone else.
D
supports a universal claim on the basis of a single example
This is the cookie-cutter flaw of overgeneralization. But the author doesn’t make a generalized or universal claim. His conclusion is a claim specifically about one candidate, and he supports that claim on the basis of a consideration of all candidates.
E
describes an individual in terms that appropriately refer only to the group as a whole
This is the cookie-cutter “whole to part” flaw, where a trait belonging to a group is inappropriately applied to a single member. The author doesn’t do this—he describes each candidate in terms of her qualifications, which is a trait that rightly applies to individuals.
Summarize Argument
The author concludes that Ziegler was insane at the time he fired the shot. This is based on the fact that the people accusing Ziegler of a crime submitted no evidence that Ziegler was sane at the time of the shot. They’ve only submitted evidence Ziegler was sane after the shot.
Identify and Describe Flaw
The author overlooks the fact that there’s evidence Ziegler was sane after the shot constitutes evidence that Ziegler was sane at the time of the shot, too. In addition, the author overlooks the fact that, even if there was a failure to submit evidence of Ziegler’s sanity at the time of the shot, that doesn’t prove Ziegler was insane at the time. Absence of evidence for a particular proposition (that Ziegler was sane at the time of the shot) does not constitute evidence against that proposition.
A
It presumes that being a well-educated professional is relevant to being guilty or innocent.
The author does not offer the claim about Ziegler’s consulting work as evidence Ziegler is innocent. So, the author does not assume that this consulting work is relevant to being guilty or innocent.
B
It concludes on the basis of evidence against Ziegler’s being sane that there is a lack of evidence for Ziegler’s being sane.
The argument is not based on evidence against Ziegler’s being sane. It’s based on the claim that there’s a lack of evidence that Ziegler was sane. Also, the argument does not conclude that there’s a lack of evidence of Ziegler’s sanity. It concludes that Ziegler was insane.
C
It fails to consider that Ziegler might have been insane when he worked as a consultant.
The author concludes that Ziegler was insane at the time of the shot. If he was also insane when he worked as a consultant, that doesn’t suggest Ziegler might have been sane at the time of the shot. So, the possibility described by (C) does not undermine the author’s reasoning.
D
It presumes that whether one is sane is relevant to whether one is morally responsible for one’s actions.
Moral responsibility has nothing to do with the argument. The author’s conclusion is that Ziegler was insane at the time he fired the shot. The conclusion is not that Ziegler shouldn’t be held morally responsible.
E
It fails to consider the possibility that Ziegler’s being sane after the shooting is an indication that he was sane at the time of the shooting.
The accusers have submitted evidence that Ziegler was sane after the shot. If this constitutes evidence that Ziegler was sane at the time of the shot, then the author’s conclusion doesn’t follow from the premises.