Digging in sediments in northern China, evidence has been gathered by

Dear Anvesh2608,

I'm happy to respond in the place of my friend & colleague Chris.

Here's the relevant text of (C):
. . . scientists have gathered evidence suggesting that . . .
The participle modifier "suggesting" is touching the noun "evidence": this juxtaposition makes it pretty clear that the participle modifies the noun "evidence." Choice (A) & (B) have more ambiguous modification patterns--that's one of the many reasons these are incorrect.

Does this make sense?
Mike

Important: When a sentence begins with a with noun modifier (as it does in the above sentence), stop at the comma and ask the question that the modifier raises.

So, once we read, Digging in sediments in northern China, we should stop and ask . . .

"Who or what was digging in sediments?"

If the sentence is properly constructed, the part that immediately follows the comma will answer that question in a logical manner.

Reading on we get...

A) ...evidence. Evidence was digging in sediments?
Makes no sense.
ELIMINATE A

B) ...evidence. Evidence was digging in sediments?
Makes no sense.
ELIMINATE B

C, D, E) ...scientists. Scientists were digging in sediments?
Makes sense.
KEEP C, D and E

Now examine the differences among the remaining answer choices
(C) scientists have gathered evidence suggesting that complex life-forms emerged much earlier than (previously thought)
Looks fine.
We have "life-forms emerged much earlier than previously thought"
KEEP for now

(D) scientists have gathered evidence that suggests a much earlier emergence of complex life-forms than that which was (previously thought)
First off, this version should seem awkward and unnecessarily verbose.
Also, it is unclear what that is referring to.
ELIMINATE D

(E) scientists have gathered evidence which suggests a much earlier emergence of complex life-forms than that (previously thought)
First of all, there's an issue with "which" (for more on this see the "that vs which" video below.
Also,it is unclear what that is referring to.
ELIMINATE E

Answer: C

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Hello Everyone!

Let's tackle this question, one problem at a time, and narrow it down to the right answer! First, here's the original question with any major differences between the options highlighted in orange:

Digging in sediments in northern China, evidence has been gathered by scientists suggesting that complex life-forms emerged much earlier than they had previously thought.

(A) evidence has been gathered by scientists suggesting that complex life-forms emerged much earlier than they had
(B) evidence gathered by scientists suggests a much earlier emergence of complex life-forms than had been
(C) scientists have gathered evidence suggesting that complex life-forms emerged much earlier than
(D) scientists have gathered evidence that suggests a much earlier emergence of complex life-forms than that which was
(E) scientists have gathered evidence which suggests a much earlier emergence of complex life-forms than that

After a quick glance over the options, a few things jump out that we can focus on:

1. Starting with evidence vs. scientists
2. Using suggesting / suggests / that suggests / which suggests
3. Ending with than they had / than had been / than / than that which was / than that

Let's start with #1 on our list because no matter which one we choose, we'll throw out 2-3 options right away. If we look at the sentence as a whole, we see that it starts with a modifier:

Digging in sediments in northern China, evidence has been gathered by scientists suggesting that complex life-forms emerged much earlier than they had previously thought.

We know that whenever we use a modifier, the person/thing/word it's referring to MUST be directly before or after it. So - what/who is digging sediments in northern China? The scientists, or the evidence? The scientists! Let's see which options place the scientists directly after the modifier:

(A) evidence has been gathered by scientists suggesting that complex life-forms emerged much earlier than they had
(B) evidence gathered by scientists suggests a much earlier emergence of complex life-forms than had been
(C) scientists have gathered evidence suggesting that complex life-forms emerged much earlier than
(D) scientists have gathered evidence that suggests a much earlier emergence of complex life-forms than that which was
(E) scientists have gathered evidence which suggests a much earlier emergence of complex life-forms than that

We can rule out options A & B because they don't place the scientists directly next to the phrase that's modifying them.

Now that we only have 3 options left, let's look at #3 on our list: how they end the phrase. It looks like some of them use the pronoun "that," while others don't. Let's take a closer look at each option to make sure the pronoun "that" is clearly referring back to something. If it's not, then we must rule it out!

(C) scientists have gathered evidence suggesting that complex life-forms emerged much earlier than
This is CORRECT! There is no pronoun here to confuse readers. It's clear, concise, and conveys the most logical meaning.

(D) scientists have gathered evidence that suggests a much earlier emergence of complex life-forms than that which was
This is INCORRECT because it has the vague pronoun "that." It's not entirely clear what "that" is referring to here: evidence, complex life-forms, scientists? If it's not 100% clear, it's not a good idea to include the pronoun!

(E) scientists have gathered evidence which suggests a much earlier emergence of complex life-forms than that
This is INCORRECT because it uses the vague pronoun "that." It's also awkward to say "than that previously thought," so let's also rule this one out.

There you have it - option C is the best choice! It places the antecedent next to the modifier and doesn't use vague pronouns, making this option the clearest and most concise option!


Don't study for the GMAT. Train for it.

Digging in sediments in northern China, evidence has been gathered by scientists suggesting that complex life-forms emerged much earlier than they had previously thought.


(A) evidence has been gathered by scientists suggesting that complex life-forms emerged much earlier than they had

(B) evidence gathered by scientists suggests a much earlier emergence of complex life-forms than had been

(C) scientists have gathered evidence suggesting that complex life-forms emerged much earlier than

(D) scientists have gathered evidence that suggests a much earlier emergence of complex life-forms than that which was

(E) scientists have gathered evidence which suggests a much earlier emergence of complex life-forms than that


Hello Experts daagh GMATNinja..

I need a small help in comparison area which is being tested here (Being usage is correct in this sentence :P)

So AB can be rejected because scientists do the action of digging.

My main doubt/concern is ---- XXX that complex life-forms emerged much earlier than previously thought.

my reasoning - complex life forms emerged (some action) much earlier than previously thought (some abstract noun)

how does the comparison make sense here? I am sorry but this type of question is a pain for me. Would appreciate if you guys can help me.

Hi Saurabh, the way to read it is:

complex life-forms emerged much earlier than (was) previously thought.

I noticed that you didn't tackle the "suggest" part in the choices. Could you elaborate? Thanks.

Hi Diwabag!

Thanks for your question! Sometimes, if we tackle easier grammar concepts, we don't have to deal with all of them. So in case you were more comfortable tackling the "suggest" section, let's break that one down:

(A) Digging in sediments in northern China, evidence has been gathered by scientists suggesting that complex life-forms emerged much earlier than they had previously thought.
This is INCORRECT because the -ing modifier (suggesting that complex life-forms emerged...) is tied to the word directly preceding it, which in this case is "scientists." The scientists didn't suggest...the evidence did! Therefore, this is wrong because it creates a modifier-antecedent problem.

(B) Digging in sediments in northern China, evidence gathered by scientists suggests a much earlier emergence of complex life-forms than had been previously thought.
This is actually OKAY how it's written. However, we would end up ruling it out later because "evidence" shouldn't be the antecedent for the modifier "Digging sediments in northern China."

(C) Digging in sediments in northern China, scientists have gathered evidence suggesting that complex life-forms emerged much earlier than previously thought.
This is CORRECT because the -ing modifier is next to "evidence," which is what it's modifying.

(D) Digging in sediments in northern China, scientists have gathered evidence that suggests a much earlier emergence of complex life-forms than that which was previously thought.
This is actually OKAY as it is. However, you would later rule it out later because it has the vague pronoun at the end of the phrase that's underlined.

(E) Digging in sediments in northern China, scientists have gathered evidence which suggests a much earlier emergence of complex life-forms than that previously thought.
This is INCORRECT because using a "which" modifier here doesn't work. By starting the modifier with "which," we're saying the information about the evidence isn't necessary to the meaning of the sentence. What the evidence is about IS important, so it needs to stay. You'd also rule this one out later because of the vague pronoun at the end of the underlined portion.

There you have it - option C is still the best option. You would still have to go through another round or two of eliminations to get to the correct choice, so it doesn't really save you any time. However, if going this route was easy for you, go for it!

I hope this helps!

Question on "that" and "which" - If "that" and "which" already used to modify something, is it necessary that the verb need to agree with the subject?
For example,
(D) scientists have gathered evidence that suggests a much earlier emergence of complex life-forms than that which was
(E) scientists have gathered evidence which suggests a much earlier emergence of complex life-forms than that

Is it suppose to be that suggest and which suggest (without "s")? Please advise.

Hello bambenya!

Great question! The verb in a modifier has to agree with the antecedent, which is not always the sentence's subject. If you ask yourself "who/what is doing the suggesting here?," you should answer "the evidence." Since "evidence" is a singular noun, you need to use the singular verb "suggests."

So to answer your question, no - the verb in a modifier does not agree with the subject UNLESS the subject is also the modifier's antecedent. In this case, the subject (scientists) and the antecedent (evidence) are not the same, so the verb in the modifier has to match the antecedent.

I hope this helps! Feel free to tag me at EMPOWERgmatVerbal if you have any more questions!

Dear AjiteshArun GMATGuruNY MartyTargetTestPrep IanStewart DmitryFarber ccooley

In the correct option, what does "than previously thought" stand for?

Digging in sediments in northern China, scientists have gathered evidence suggesting that complex life-forms emerged much earlier than previously thought.

According to https://www.manhattanprep.com/gmat/foru ... 23846.html,

I don't quite agree with the above because I don't think we can omit the verb when there is shift in tense -- from present perfect to past perfect.

There is no such rule - "In the proposed bill, scientists will get more funding than before" changes verb tense and omits the second verb.

But the "complex life forms" sentence you quote doesn't omit the verb (it omits the subject "scientists"). Inserting "had" in the rephrasing is optional; the sentence means the same thing without it.

I got a small issue here, hope someone could help!

the correct answer goes: scientists have gathered evidence suffesting that complex life-forms emerged much earlier than previously thought.

but I wonder if this revision can also be correct: scientists have gathered evidence suffesting that complex life-forms emerged much earlier than they previously thought to be.

I have seen sentence like this before, but not sure how to correctly use it.

Many thanks!

Hey,

May be the below helps, but look for an expert’s post as well.

In ur revision “they” would be ambiguous, possibly referring to scientist or the life forms”

The “be” verb in previously thought to be cannot stand in for emerged as be is a state verb and emerged is an action verb.

Next
Thought can be used in 2 ways
Action
- thought X to do Y
- thought that X does Y

Similar to state
-thought X to be Y
-thought that X is Y

Now,

Look at the first half
Scientists have gathered evidence suggesting that complex life forms emerged

much earlier than

Parallel 2nd half
Scientists previously thought
(That) complex life forms emerged.

This is second usage of thought. Ok to drop the that.

Next
scientists previously thought complex life forms did.
This is again the second usage of thought. Replace “emerged” with did. Ok

Next
Scientists previously thought
Second usage. We dropped the clause after thought by virtue of parallelism. Note it appears in the first half.

Next
previously thought.
By virtue of parallelism we know it is the scientists, and so ok to drop it.





Now coming to the first use of thought
First half - that clause
Scientists have gathered evidence suggesting that complex life forms emerged

Much earlier than

Second half - infinitive
Scientists previously thought them (lifeforms) to have emerged.

This is ok.

Next
Scientists previously thought them to have.

Dropping emerged should be ok as it appears earlier in the sentence in the desired verb form.

Now if the first half were
Scientists have gathered evidence claiming complex life forms to have emerged

Much earlier than

Scientists previously thought them to have.

Then by virtue of parallelism it would be ok to drop scientists and them to have.

In the end you get previously thought.

But since the first half has the suggesting “THAT”, I would deduce the second usage of thought and complete the second half by parallelism.

Though any experts are free to opine and confirm.

Posted from my mobile device

Hello krndatta,

Thank you for the PM on this question.

You asked:




Choice E in this form is incorrect because the phrase "previously thought" acts merely as the modifier for emergence. This modifier just presents some additional information. So, in essence, Choice E compares emergence with emergence, not the difference in timing of emergence. Choice E does not present the logical intended comparison.


Hope this helps.
Thanks.
Shraddha

Hi mikemcgarry,

I really have a problem with "Parallelism question". Sometimes, I am not sure whether there are words or phrases dropped or omitted. For example, from your mention above "Digging in sediments in northern China, scientists have gathered evidence suggesting that complex life-forms emerged much earlier than when complex life-forms were previously thought to emerge. " How do we actually know that which word is "thought" parallel to, or "when complex...... thought to emerge" is dropped

Thank you,
Tan

Following the approach below, I solved this problem in under a minute.

I immediately notice that the non-underlined portion is a present participial phrase ("Digging...China"), which is an opening modifier that will describe the subject of the sentence. Choices 1 and 2 are unacceptable as "evidence" cannot dig.

Among choices 3, 4, and 5, I notice that the subject and verb are the same in all choices. I turn my attention to the comparison.

(C) ...evidence suggesting that complex life-forms emerged much earlier than previously thought
(D) ...evidence that suggests a much earlier emergence of complex life-forms than that which was previously thought
(E) ...evidence which suggests a much earlier emergence of complex life-forms than that previously thought

Choice 3: the comparison seems to make sense, so I keep this option and move on. (To be honest, I didn't really worry much about what the ellipsis was here, as I was focused on finding things that were wrong.)

Choice 4: the word "that" seems to have to refer to "emergence", in which case the comparison would be
"than the emergence which was previously thought"
Since "which" refers to emergence, we have the clause "the emergence was previously thought", which is not a finished thought. Wrong.

Choice 5: essentially the same problem as number 4. We end up having "that" have to equal "emergence", giving us "than the emergence previously thought", which does not make sense as a comparison. Wrong.

It has to be number 3.

I still don't understand how emerged can be compared with previously thought? Can anyone explain it further.