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- Wed Aug 20, 2014 11:00 pm
#35173
Complete Question Explanation
Strengthen, CE. The correct answer choice is (A)
Here, the author draws a conclusion about male guppy courting behavior. In a study of guppy fish,
researchers observed male guppies that had more orange on one side of their body than on the other.
These fish were permitted to show whichever side they preferred to the female guppies. It turns
out that the males were more likely to show their orange side to the females when courting. The
researchers also observed that the females were drawn to the males showing more orange. From
this evidence, the author concludes that “a male guppy will alter its courting patterns in response to
feedback from a female guppy.”
The author’s conclusion is causal, but there is no evidence to support the view that the male guppies
showed more orange in response to any feedback from the female guppies. All we know is that the
female guppies were drawn to the male guppies showing more orange. While the evidence certainly
establishes the existence of a correlation, it does not support the definitive causal conclusion reached
by the author.
The question identifies this as a Strengthen question. Our prephrase is that the correct answer choice
will provide evidence of an actual causal relationship between the female guppies being drawn to the
males showing more orange and the male guppies choosing to show the female guppies more orange.
Answer choice (A): This is the correct answer choice. Essentially, it tells us that when the
purported cause (i.e., the female guppies being drawn to the male guppies showing more orange)
was removed, then the effect was missing as well. This is evidence of regularity that is necessary to
establish a definitive causal relationship (i.e., when the cause is present the effect occurs, and when
the cause is absent the effect does not occur).
Answer choice (B): The preferences of females of other species is irrelevant to the conclusion of this
argument about guppies.
Answer choice (C): The comparative rate at which male guppies father offspring is not relevant to
the issue of whether the female’s apparent expression of preference causes the male guppies to show
more orange.
Answer choice (D): This answer choice is incorrect because the key information about the female
guppies was their action in giving feedback, not their coloring.
Answer choice (E): This answer choice tends to weaken the conclusion, because it restricts the extent
to which the female guppies were able to provide feedback to the male guppies.
Strengthen, CE. The correct answer choice is (A)
Here, the author draws a conclusion about male guppy courting behavior. In a study of guppy fish,
researchers observed male guppies that had more orange on one side of their body than on the other.
These fish were permitted to show whichever side they preferred to the female guppies. It turns
out that the males were more likely to show their orange side to the females when courting. The
researchers also observed that the females were drawn to the males showing more orange. From
this evidence, the author concludes that “a male guppy will alter its courting patterns in response to
feedback from a female guppy.”
The author’s conclusion is causal, but there is no evidence to support the view that the male guppies
showed more orange in response to any feedback from the female guppies. All we know is that the
female guppies were drawn to the male guppies showing more orange. While the evidence certainly
establishes the existence of a correlation, it does not support the definitive causal conclusion reached
by the author.
The question identifies this as a Strengthen question. Our prephrase is that the correct answer choice
will provide evidence of an actual causal relationship between the female guppies being drawn to the
males showing more orange and the male guppies choosing to show the female guppies more orange.
Answer choice (A): This is the correct answer choice. Essentially, it tells us that when the
purported cause (i.e., the female guppies being drawn to the male guppies showing more orange)
was removed, then the effect was missing as well. This is evidence of regularity that is necessary to
establish a definitive causal relationship (i.e., when the cause is present the effect occurs, and when
the cause is absent the effect does not occur).
Answer choice (B): The preferences of females of other species is irrelevant to the conclusion of this
argument about guppies.
Answer choice (C): The comparative rate at which male guppies father offspring is not relevant to
the issue of whether the female’s apparent expression of preference causes the male guppies to show
more orange.
Answer choice (D): This answer choice is incorrect because the key information about the female
guppies was their action in giving feedback, not their coloring.
Answer choice (E): This answer choice tends to weaken the conclusion, because it restricts the extent
to which the female guppies were able to provide feedback to the male guppies.
