#17 - Some classes of animal are so successful that they

[Administrator]

Complete Question Explanation

Flaw in the Reasoning. The correct answer choice is (E)

The conclusion of the argument is given in the last sentence: no species of any is a threatened species. The strong wording of this conclusion should catch your eye, as it is difficult to prove such an absolute statement. The author bases this argument on the fact that ants are the most successful of insects, and insects are a type of species that spread into virtually every ecosystem (as opposed to other species that inhabit small geographical areas and thereby become threatened). This is an error of division: just because ants in general are good at spreading into new ecosystems and avoiding threats in that particular way, does not mean that every single species of ant is free from all threatening elements.

Answer choice (A): The argument is discussing the range from the Arctic Circle to Tierra del Fuego, not those specific locations as isolated places.

Answer choice (B): The argument is not trying to claim that ants are unlike other insects, but rather the author claims that all ants are free from all threats. The problem is that just because this may be true for ants in general does not necessarily mean it is true for every single ant species.

Answer choice (C): Again, the flaw is not that the author misuses/incorrectly assumes something about the word “threat,” but instead that the author makes a sweeping generalization about every type of ant when it may only be true for most ants or for ants in general (there could still be some threatened ant species even if ants in general have the qualities described).
Answer choice (D): This is a reversed answer (an error of composition, rather than division). For this to be correct, the author would have to conclude that because something was true for a single species of ant (or a few species) it must be true for all species of ants.

Answer choice (E): This is the correct answer choice. As mentioned previously, the error is that the author gives information about ants as a whole and then attempts to apply that to every type of ant. This is known as an error of division.

[ylikate]

While I see the merit of (E), can someone help me understand why (C) is incorrect?

I believe AC (C) also indicates a flaw. The argument assumes the ability to spread into virtually every ecosystem is the only way to avoid being "Threatened". It concludes based on this assumption that since Ants are successful at spreading, "no species of ant is a threatened species."

More broadly, can assumption be a flaw??

[Steve Stein]

Hi ylikate,

The problem with answer choice C is that in this example, the author does not take for granted that spreading into every ecosystem is the only way to avoid threat. An unwarranted assumption can certainly be a flaw, but this choice does not describe the flaw presented in this stimulus.

I hope that's helpful! Please let me know whether this is clear--thanks!

~Steve

[egarcia193]

I got this one wrong I had the correct paraphrase and knew it was a part to whole argument since they said that ants inhabit virtually everywhere than they,must not be threatened but chose D I was confused between D and E because of the language and wasn't sure which one was correct but chose D because I thought the way it was worded was better and correct than E. Can anyone explain the difference D and E in their language and what they actually mean compared to each other ?

[AthenaDalton]

Hi egarcia,

The flaw in answer choice (E) is assuming that what is true of the whole, is also true for each part. In the prompt, the author argues that since ants, as a class of animal, have spread to virtually every ecosystem, then each individual species of ant must be thriving and not endangered. The author is assuming that since ants generally are hardy and can survive well, every single type of ant also has this characteristic. This overlooks the possibility that of the thousands of different ant species in the world, a handful of species are very fragile.

The flaw in answer choice (D) is assuming that what is true of a part, is true of the whole. This flaw isn't reflected in the prompt. A part-to-whole flaw would look like this: "fire ants, a particular species of ants, are an incredibly robust species and can survive in extreme conditions, from deserts to arctic tundra. Since this one species of ant is really hardy, all 12,000 species of ants that exist worldwide must be tough as well."

Hope this makes sense! Good luck!

[egarcia193]

Thanks, I had the correct paraphrase but I see now I mixed what the wording in each answer meant and i believed that D was actually describing a whole to part when it was actually doing the opposite

[George George]

@egarcia193 Good catch! Now you know the for the future and you have leveled up!