In California, a lack of genetic variation in the Argentine ant has

https://www.nytimes.com/2000/05/30/science/observatory.html

Nothing quite that creepy is going on in California, but the state has been overrun by a species of ant that, researchers say, has essentially formed a single giant colony from San Diego to San Francisco and beyond. The researchers, from the University of California at San Diego, discovered a lack of genetic variation in the insect, the Argentine ant, which has allowed the species to spread to nooks and crannies up and down the state, particularly in coastal areas.

Individual ants are so close genetically, the researchers report in The Proceedings of the National Academy of Sciences, that they consider all their fellows to be close relatives and thus do not engage in the kind of fierce intercolony death matches that limit the ants in their native Argentina.

The Argentine Ant



First glance

The answer choices begin with either due to or because of. Generally-accepted grammar rules state that due to is used with nouns or noun phrases and because of is used with clauses, though the distinction can sometimes be a judgment call.

For this reason, perhaps, the GMAT does not appear to test this issue formally; the Official Guide explanations for all problems dealing with because of vs. due to do not address these differences. Therefore, ignore this issue.

Issues

(1) Subject-Verb: struggles that limits

The original sentence says the following: the kind of struggles that limits the spread of this species. The word that, when preceded by a noun, is a noun modifier. In this case, it is referring to the noun just before, struggles: the struggles limit the spread of the species. Answer (A) pairs a plural noun with a singular verb; eliminate it. Also eliminate answers (C) and (E), which repeat this error.

(2) Noun-Noun: fellows … a close relative

The original sentence contains the language the ants consider all their fellows to be a close relative.

All their fellows cannot be a single relative; rather, they would be close relatives. Eliminate choices (A), (B), and (E) for this error.

(3) Comparison: similar

If one thing is similar to another, it is necessary to include the another portion of the comparison. Answers (B) and (C) do not actually indicate what the ant is similar to. (Note: it is possible to omit the separate mention of another if a plural construction is used. For example, this is correct: The twins are so similar! Since there are two twins, the comparison is to each other.)

The Correct Answer

Correct answer (D) properly pairs the plural noun struggles with the plural verb limit and the plural noun fellows with the plural description close relatives.

Note: this correct answer contains a tempting trap that might cause someone to cross it off. The plural pronoun they appears not to match the singular Argentine ant mentioned at the beginning of the sentence. It’s true that this pronoun does not go with this noun; rather, it goes with the plural word ants that appears after the pronoun they.