Australian embryologists have found evidence that suggests that the elephant is descended from an aquatic animal, and its trunk originally evolving as a kind of snorkel.
(This question is from Official Guide. Therefore, because of copyrights, the complete question cannot be copied here. The question can be accessed at GMAT Club)
The sentence says that Australian embryologists have found evidence that suggests something. What does it suggest? Let’s focus on this part:
- that suggests
- that the elephant is descended from an aquatic animal,
- and its trunk originally evolving as a kind of snorkel
The evidence suggests two things:
- The elephant is a descendant of an aquatic animal
- The trunk of the elephant originally evolved as a kind of snorkel (or if you don’t know the meaning of snorkel, you can think it as “kind of something”)
There are two clear problems with this sentence – both in latter part of “and”:
- “its trunk originally evolving as a kind of snorkel” doesn’t have a verb. The “trunk” is followed by a verb-ing modifier. Logically, the idea communicated in this part seems to be suggested by the evidence. Therefore, it needs to be parallel to the clause before “and”. In other words, we need to change “evolving” (a modifier) to a verb in this part to make it correct.
- The other problem is that we need to repeat “that” after “and” to make it parallel to “that the elephant is …”. Please remember that we cannot take “that” as common to the two clauses. Why do we need to repeat it? Because without such repetition, one can possibly understand the part after “and” to be another independent clause and not something suggested by the evidence.
There’s another problem that is not-so-major and about the quality aspect of the sentence. It doesn’t seem very polished to write two thats one after the other – “that suggests that”. One way to change the same is by writing “suggesting that”.
(Please note that “is descended” is absolutely correct, no matter how wrong it may sound to you. This construction is same as “This plant is grown from hybrid seeds”. “Grown” and “descended” are both past participle forms of the corresponding verbs. Saying “the elephant has descended” would mean that the elephant has done the action of descending.)
(Another point to note here is that “suggest” is one of the bossy verbs requiring a subjunctive verb after them e.g. I suggest that he be called. However, there’s another use of “suggest”, in which it means “indicates”. This is the way “suggest” is used in this sentence.)
(A) Incorrect. For the errors pointed above.
(B) Incorrect. For the following reasons:
- “evidence has suggested” means that the evidence has completed the action of “suggesting” in the recent past. However, logically, we know that such an action has not been completed and that the evidence still suggests whatever it suggests. So, the use of present perfect is incorrect in this context.
- “the elephant descended” means that the elephant did the action of “descending”. Clearly, it doesn’t make sense to say so. The elephant is the result of this “descending”, so it cannot possibly do the action. (Some people may also notice the absence of “that” after ‘suggested’. However, this is not an error. There are situations in which we can omit ‘that’. For example: “He confirmed that he did not go to the graveyard” is perfectly fine.)
- “its trunk originally evolving” is now playing the role of a “Noun + Noun modifier”, correctly punctuated with a comma. However, using this modifier distorts the meaning; now, it doesn’t seem that the evidence suggests that the trunk originally evolved as a kind of snorkel.
(C) Incorrect. For the following reasons:
- “had descended” is incorrect for two reasons. First, it indicates that the elephant performed the action of “descending”. Second, the use of past perfect is incorrect. There is no event in the simple past with which this event is sequenced.
- “with its trunk originally evolved” introduces two more errors. First, the preposition ‘with’ is followed by a clause (trunk: subject, evolved: verb). A preposition must always be followed by a noun phrase and never be followed by a clause. Second, this construction distorts the meaning; now, it doesn’t seem that the evidence suggests so.
(D) Incorrect. For the following reasons:
- “had descended” is wrong for the reasons explained above.
- “that” is missing after ‘and’.
(E) Correct. This option corrects all the errors in the original sentence without bringing in any new errors. “evidence to suggest” is correct and means the almost the same as “evidence that suggests”. The subtle difference is that in the latter case, the evidence is suggesting something but in the former case, the evidence is just leading to the suggestion, not doing the “suggesting” itself. The difference is subtle and not relevant to the question.