25. (A)
Question Type: Identify the Flaw
The argument made by some anthropologists is that if humans survived then we can conclude that they had the ability to adapt to diverse environments:
survival (sufficient condition) -> ability to adapt (necessary condition)
The author makes a suspect conclusion: the anthropologists are wrong because one case exists in which a species had the ability to adapt but did not survive. In other words, the author assumes that "survival -> ability to adapt" implies "ability to adapt -> survival." The author has reversed the logic and confused the sufficient condition with the necessary condition. Ability to adapt is NOT sufficient to cause survival, as a species may have any one of many other shortcomings that could lead to extinction. Answer (A) expresses this flaw in logic.
This is a confusing argument, so let’s try an analogous argument that contains the same flaw:
Many people say that because John lives in San Francisco he therefore lives in California. But these people are wrong because I know someone who lives in California who does not live in San Francisco.
In this argument, San Francisco is sufficient to require California (someone living in San Francisco MUST live in California), but living in California is NOT sufficient to require San Francisco, is it? It would be an error to assume that it does. The author of the argument makes a similar mistake.
(B) is not an error made by the argument.
(C) is not an error made by the argument. A generalization is not made from a specific case.
(D) is very tempting. It is incorrect, though, because the author doesn’t necessarily fail to consider that the species may have had some characteristics that lessened its chances of survival. Rather, the author errs in concluding, regardless of what he or she believes about the species’ other characteristics, that the species’ ability to adapt was in itself sufficient to guarantee survival.
(E) is in incorrect because it introduces causality. This argument does not introduce any cause/effect relationships. Remember, conditional relationships are NOT necessarily causal relationships.
#officialexplanation