V34-06

Official Solution:


In trap-jaw ants, Odontomachus bari, known for two distinct modes of aerial locomotion, an entirely new function, propulsion, evidently evolved for a system that already had a purely functional purpose: dismembering prey.


A. In trap-jaw ants, Odontomachus bari, known for two distinct modes of aerial locomotion, an entirely new function, propulsion, evidently evolved for a system that already had a purely functional purpose: dismembering prey.
B. The jaws of trap-jaw ants, Odontomachus bari, known for two distinct modes of aerial locomotion, evidently evolved an entirely new function, propulsion, for a system that already had a purely functional purpose: dismembering prey.
C. Propulsion, an entirely new function, evidently evolved for a system that already had a purely functional purpose, dismembering prey, in trap-jaw ants, Odontomachus bari, known for two distinct modes of aerial locomotion.
D. Known for two distinct modes of aerial locomotion, trap-jaw ants, Odontomachus bari, evidently evolved an entirely new function, propulsion, for a system that already had a purely functional purpose: dismembering prey.
E. Dismembering prey, a purely functional purpose for a system that evidently evolved an entirely new function, propulsion, is what trap-jaw ants, Odontomachus bari, are known for, as well as two distinct modes of aerial locomotion.


Even if the whole line is underlined here, this should feel like a walk in the park compared to the set of four questions yesterday from a dry economics passage. Get ready. Since the whole sentence is, in fact, underlined, I will skip straight to the answer choices.





The sentence is difficult to follow, but nothing is grammatically wrong with it. You should always ask yourself what the subject of the sentence is when you approach an SC question. Here, the subject is function, believe it or not. There is an opening prepositional phrase, followed by an appositive phrase (the scientific name of the trap-jaw ant), then a modifying phrase, and finally the main clause, which itself gets interrupted. I have written before in this challenge that the GMAT™ tends not to prefer left-branching sentences, those that stack dependent clauses or phrases ahead of the main clause. I think this sentence can help you appreciate why. Again, even though nothing is grammatically wrong with the highlighted portion, the beginning of the sentence is choppy and difficult to follow. You could yellow light the answer for now, but you should keep looking for a clearer alternative.





Blink, and you may miss the subtle difference between what makes this a red light answer and what makes the previous answer slightly better. Whereas before, the ants themselves were the focus of the opening phrase, this sentence places an emphasis on the jaws of the ants specifically. Before, what was known for two distinct modes of aerial locomotion had to be, again, the ants themselves. The first three phrases of this iteration of the sentence can be interpreted in two ways:

1) The jaws of trap-jaw ants are known for two distinct modes of aerial locomotion. (In this case, the scientific name is interrupting to provide additional information on the ants.)

2) Odontomachus bari is known for two distinct modes of aerial locomotion. (In this case, both the O. bari and the known for phrases are interrupting the main clause: the jaws of trap-jaw ants evidently evolved...)

We want clarity of meaning, not a guessing game as to which interpretation is correct, nonsensical though flying jaws may be.





Three options in, and we get yet another unique subject of the sentence: propulsion. As we saw in (A), this answer choice has no outright incorrect elements to single out. Yet it remains off-putting, in terms of the conveyed meaning. Why? Even if the subject and verb appear at the head of the sentence (making it right-branching), in terms of meaning, we have no idea what the sentence is about—i.e. in which organism propulsion evolved, or what kind of purely functional system had an older use in dismembering prey—until we reach the latter part of the sentence. It is difficult to juggle all this information and keep matters straight by the time we encounter the ants. For this reason, I would yellow light this option in my first pass, but I would be thinking that a better line probably existed in one of the last two answer choices.





The opening phrase now clearly modifies trap-jaw ants, the subject of the main clause; the scientific name is listed right after; and the main clause wraps up with its predicate ([verb] + [object]) immediately after. Although not the easiest of sentences to follow, this version is way better than anything we have yet encountered. We do not get anything evolving internally before we have been introduced to the larger organism, as we saw in (C). We do not get ambiguity of meaning, as we saw in (B). And we do not delay the main clause more than is necessary to provide the sentence a clear direction, as we saw in (A). If you were still on the fence between, say, this answer and (A), you could ask yourself what the sentence seemed to be about. The earlier sentence is built around the word function, while this one is centered on ants.





I would like to think that this is the easiest iteration to eliminate, but I am not always accurate in my assessment of how others will approach a question. Although again, there is nothing grammatically wrong with the sentence, it feels off in a way that the others did not. Dismembering prey, a gerund, is now the subject of the main clause, but that clause follows an unwieldy construct: dismembering prey... is what [noun clause]. That sounds rather juvenile, and it serves as a hint that there is likely a better way to express the same idea. Furthermore, just as we saw in (C), we get all of this ethereal or detached information about the ants before we ever see mention of them later on. That does not make for a clear and easy read. Finally, I can see an argument being brought up about how the meaning of the sentence has been changed to indicate that trap-jaw ants are known primarily for dismembering prey. Even if the rest of the sentences do not follow this path, because the entire original sentence is underlined, we cannot point to the first sentence or any other as the one that expresses the intended meaning. This one simply loses out for other, more compelling reasons outlined above.

I hope that helps. If nothing else, this question should serve as a reminder to focus on meaning in SC. All five sentences here are perfectly grammatical, but all but one fail to measure up to an answer standard for lack of clarity. I had a lot of fun with this competition, and I hope you did, too.


Answer: D