The question stem reads: The biologist’s argument is most vulnerable to criticism on which one of the following grounds? This is a Flaw question.
The biologist begins by describing how many paleontologists suggest that the difficulties of the ice age were a cause of the evolution of the human brain. The biologist concludes those palentologists are wrong. In other words, the ice age was not responsible for the evolution of the human brain. As evidence, the biologist cites that many animal species survived the ice age with no evolutionary changes to their brain.
The biologist has hypothesized that the ice age was not repsonsbile for the evolution of the human brain. If we were to construct an ideal experiment to test this hypothesis, what kind of subjects would you want to use? You would want to use human brains! However, the biologist instead uses animals brains as evidence. The question is, “Are humans and animals” the same? Maybe. Maybe not. The biologist’s argument relies on the assumption that humans and animals would respond to the evolutionary pressures of the ice age in the same way. So let’s look for an answer choice that distinguishes how animal brains and human brains would respond to the ice age.
Answer Choice (A) is incorrect. The biologist does not suggest that the ice age was sufficient or necessary to produce brain evolution in humans or animals.
Correct Answer Choice (B) draws the distinction between humans and animals that we are looking for. The biologist fails to consider the possibility that the ice age could have produced the evolution of the brain in humans without producing the evolution of the brain in other species.
Answer Choice (C) is incorrect. The argument is not about whether the ice age was necessary for producing changes in the brains of humans or animals. The argument is about whether the ice age was sufficient to bring about changes in the brains of humans and animals.
Answer Choice (D) is incorrect. The biologist never presumes that humans had a more difficult time during the ice age than animals.
Answer Choice (E) is incorrect. The biologist does not presume that the ice age was causally responsible for the evolution of human brains. He concludes that the ice age was not casusualy responsible for the evolution of human brains.
A
It fails to address adequately the possibility that even if a condition is sufficient to produce an effect in a species, it may not be necessary to produce that effect in that species.
B
It fails to address adequately the possibility that a condition can produce a change in a species even if it does not produce that change in other species.
C
It overlooks the possibility that a condition that is needed to produce a change in one species is not needed to produce a similar change in other species.
D
It presumes without warrant that human beings were presented with greater difficulties during ice ages than were individuals of most other species.
E
It takes for granted that, if a condition coincided with the emergence of a certain phenomenon, that condition must have been causally responsible for the phenomenon.
The question stem reads: The biologist’s argument is most vulnerable to criticism on which one of the following grounds? This is a Flaw question.
The biologist begins by describing how many paleontologists suggest that the difficulties of the ice age were a cause of the evolution of the human brain. The biologist concludes those palentologists are wrong. In other words, the ice age was not responsible for the evolution of the human brain. As evidence, the biologist cites that many animal species survived the ice age with no evolutionary changes to their brain.
The biologist has hypothesized that the ice age was not repsonsbile for the evolution of the human brain. If we were to construct an ideal experiment to test this hypothesis, what kind of subjects would you want to use? You would want to use human brains! However, the biologist instead uses animals brains as evidence. The question is, “Are humans and animals” the same? Maybe. Maybe not. The biologist’s argument relies on the assumption that humans and animals would respond to the evolutionary pressures of the ice age in the same way. So let’s look for an answer choice that distinguishes how animal brains and human brains would respond to the ice age.
Answer Choice (A) is incorrect. The biologist does not suggest that the ice age was sufficient or necessary to produce brain evolution in humans or animals.
Correct Answer Choice (B) draws the distinction between humans and animals that we are looking for. The biologist fails to consider the possibility that the ice age could have produced the evolution of the brain in humans without producing the evolution of the brain in other species.
Answer Choice (C) is incorrect. The argument is not about whether the ice age was necessary for producing changes in the brains of humans or animals. The argument is about whether the ice age was sufficient to bring about changes in the brains of humans and animals.
Answer Choice (D) is incorrect. The biologist never presumes that humans had a more difficult time during the ice age than animals.
Answer Choice (E) is incorrect. The biologist does not presume that the ice age was causally responsible for the evolution of human brains. He concludes that the ice age was not casusualy responsible for the evolution of human brains.
A
Australia has considerably fewer species of carnivorous mammals than any other continent does but about as many carnivorous reptile species as other continents do.
B
In ecosystems in which there is relatively little food carnivorous mammals are at a disadvantage relative to carnivorous reptiles.
C
The unusual sparseness of Australia’s ecosystems is probably the reason Australia has considerably fewer carnivorous mammal species than other continents do but about as many carnivorous reptile species.
D
The reason that carnivorous mammals are at a disadvantage in ecosystems in which there is relatively little food is that they must eat much more in order to survive than carnivorous reptiles need to.
E
Because Australia’s ecosystems are unusually sparse, carnivorous mammals there are at a disadvantage relative to carnivorous reptiles.
A
Some people have surmised that a hardware store will be opening in the shopping plaza.
B
A hardware store will not be opening in the shopping plaza.
C
If somebody were going to open a hardware store in the shopping plaza, that person would already have started publicizing it.
D
It would be unwise to open a hardware store in the shopping plaza.
E
There has been no publicity concerning the opening of a hardware store in the shopping plaza.
A recent epidemiological study found that businesspeople who travel internationally on business are much more likely to suffer from chronic insomnia than are businesspeople who do not travel on business. International travelers experience the stresses of dramatic changes in climate, frequent disruption of daily routines, and immersion in cultures other than their own, stresses not commonly felt by those who do not travel. Thus, it is likely that these stresses cause the insomnia.
Summarize Argument: Phenomenon-Hypothesis
The author hypothesizes that increased stress causes more insomnia in businesspeople who travel relative to those who don’t. This is because travelling exposes you to stressors that you wouldn’t have at home.
Notable Assumptions
The author assumes that there isn’t some other factor that makes travelling businesspeople more likely to have insomnia. In other words, the author assumes that stress is the important factor here, and not something else—maybe people who travel for business have more demanding jobs, which makes them more prone to insomnia.
A
Most international travel for the sake of business occurs between countries with contiguous borders.
This does not affect the argument. Most business travel occurring between countries with contiguous borders doesn’t tell us about how similar those countries are culturally and climate-wise. We would have to make several assumptions for this to have any impact.
B
Some businesspeople who travel internationally greatly enjoy the changes in climate and immersion in another culture.
This does not affect the argument. It could be that people enjoy the experience but still feel the stresses described. Also, the argument claims travelling businesspeople are more likely to have insomnia—the author isn’t arguing that all of them do.
C
Businesspeople who already suffer from chronic insomnia are no more likely than businesspeople who do not to accept assignments from their employers that require international travel.
This strengthens the argument by addressing a potential alternative explanation for the phenomenon: that businesspeople who already have insomnia are more likely to travel than businesspeople who don’t have insomnia. This would mean the stress has nothing to do with it.
D
Experiencing dramatic changes in climate and disruption of daily routines through international travel can be beneficial to some people who suffer from chronic insomnia.
This does not affect the argument. (D) says people who already have insomnia may benefit from the stresses described. This is outside the scope of the causal mechanism described in the stimulus, which is that the stresses cause insomnia in the first place.
E
Some businesspeople who once traveled internationally but no longer do so complain of various sleep-related ailments.
This does not affect the argument. We don’t know if these ailments include insomnia, which is what we’re concerned with. Also, the stimulus only discusses stress as the cause of insomnia for travelling businesspeople—other people can have insomnia for other reasons.