PrepTest 123, Section 3, Question 25
By Brandon Beaver | Published October 29, 2024
Type: Flaw
Difficulty:
Explanations
This confuses sufficient for necessary. The anthropologists say that coping with diverse natural environments was necessary to survival. The author “disproves” that by citing a (flimsy) example where a species had that ability but died. If the anthropologists claimed it was sufficient, then yes, an example where the condition was met but did not cause the predicted outcome (survival) would disprove the anthropologists. However, that’s not what they said—they said it was necessary, not sufficient.
A
Bingo. Just as predicted.
B
No, the author doesn’t say that at least one other species must have had the same characteristic. The author uses that other species to “disprove” the anthropologists.
C
No, that one species didn’t survive.
D
This isn’t the flaw, because of what I mentioned above. If the anthropologists said it was sufficient, then the author would be correct. But the anthropologists didn’t say that—that is the flaw.
E
No, the issue is that it was necessary.
Passage
Some anthropologists argue that the human species could not have survived prehistoric times if the species had not evolved the ability to cope with diverse natural environments. However, there is considerable evidence that
Australopithecus afarensis
, a prehistoric species related to early humans, also thrived in a diverse array of environments, but became extinct. Hence, the anthropologists' claim is false.
Question 25
The reasoning in the argument is most vulnerable to criticism on the grounds that the argument
confuses a condition's being required for a given result to occur in one case with the condition's being sufficient for such a result to occur in a similar case
takes for granted that if one species had a characteristic that happened to enable it to survive certain conditions, at least one related extinct species must have had the same characteristic
generalizes, from the fact that one species with a certain characteristic survived certain conditions, that all related species with the same characteristic must have survived exactly the same conditions
fails to consider the possibility that Australopithecus afarensis had one or more characteristics that lessened its chances of surviving prehistoric times
fails to consider the possibility that, even if a condition caused a result to occur in one case, it was not necessary to cause the result to occur in a similar case