Paranthropus are a group of hominids that existed at the same time

OFFICIAL EXPLANATION



THE PROMPT

This question tests verb tenses, parallelism, elliptical construction, substitution, and logic.

You could easily overthink this question.
You can avoid overthinking by moving your eyes to the next option.

No kidding. Simply switching gears may get you out of "freeze" mode. Switching gears may help activate your parasympathetic nervous system, which counters stress.

Eliminate the four worst answers. Do not search for what you think is a perfect answer.
If you cannot decide whether to eliminate an option within a few seconds, keep it tentatively and move on.
You will find clearly incorrect answers to eliminate if you keep going.

THE OPTIONS

• I see no errors

• Meaning? Very simple.
Paranthropus, Australopithicus, and "some other" hominid species all existed at the same time.

• Parallelism?
Does this option create a lack of parallelism because Paranthropus is followed by a verb whereas Australopithicus and some other species of the Homo genus are not [followed by a verb]?

→ No. This option can be rewritten as I have done in the highlighted version above.

-- The sentence is parallel because the nouns on the other side of "at the same time as" are followed by the verb existed even though the verb is not actually written out the second time.
-- (More on why the word is not written out in a moment.)
-- The noun/verb structure is maintained.

→ Ellipsis
We can and often should omit words that are "common" to (shared by) both parts of the sentence.
-- In this case, the verb existed is omitted from the actual text but [the verb existed is] implied by its presence in the
first part of the sentence.

-- We use this omission to make our writing or speech concise.

-- This structure is called ellipsis, elliptical construction, or occasionally, elision.

-- As I mentioned, those omitted words are implied and thus [those omitted words] are "still there" in the strict sense.

In a few sentences above, I used omissions, which are indicated by text in brackets that I could leave out of those sentences.

• In short, the word existed does not need to be repeated.
See Notes, below.
KEEP A

• had existed is incorrect in both instances
→ we use the past perfect tense had existed to depict the earlier of two past events
→ These groups—Paranthropus, Australopithecines, and "some others"—existed at the same time.

→ In addition, we do not use past perfect (had + __ED) when simple past will suffice
Wrong: He had called a cab.
Correct: He called a cab.
ELIMINATE B

• we cannot use had as a substitute for existed.

→ IF the original verb contains had, then we can repeat just the "had" part later in the sentence
-- Correct: When the train lurched, people in the aisles stumbled, but I had sat down by then, as had Daniel.

→ If the original verb does not contain had as an auxiliary, and we want to use a shortened verb phrase, we use did or did so.
Correct: The train seemed unsteady, so I sat down, as did Daniel.

• had is not needed because past perfect is inappropriate, and
• had cannot be used as a substitute for existed
ELIMINATE C


• existing does not fit with the timeline in which at least three hominid groups existed at the same time between two and four million years ago.

• we speak about scientific facts with present tense verbs such as are, but because we are talking about a historical fact, that part should be rendered in past tense.

The present participle existing is confusing and illogical.

→ existing should be changed to that existed

ELIMINATE D

• existing presents the same problems as those in option D.

• The problem may be exacerbated in (E) because the present participle existing is placed right before past tense "were the Australopithecines. . .."

• and what is this "were" word supposed to be doing? What verb is were drawing upon?
→ no were existing is present.
-- We cannot repeat an elided verb that never existed in the first place
-- That is, we cannot shorten were existing to were because were existing never showed up in the first place
-- Besides, 99.9% of the time were existing is horrible English and you will never see that phrasing on the GMAT
ELIMINATE E

The correct answer is (A)

Notes

Heads up: Feel free to skip this section if you are just starting to study or if you are not aiming for a high Verbal score and you become frustrated.

This material is dense and very difficult to present in a Butler post.

Ellipsis - omission of words

→ In English, in the second part of a sentence, we often do not repeat simple verbs.
-- Correct: Samuel cooks breakfast more often than Safia.
-- Meaning: Samuel cooks breakfast more often than Safia cooks breakfast.

No confusion exists because we know that Samuel does not cook Safia, for breakfast or otherwise.

-- The verb existed in option A is similarly simple. Omitting existed does not create confusion if you understand that such omission is common.

→ when can we omit a verb or verb phrase? Answer: On the GMAT, we can frequently do so as long as the sentence still makes sense.

We could not say, for example, "My brother likes Greek food more than my sister."
-- That sentence is ambiguous. It could mean:
(1) My brother likes Greek food more than he likes my sister, or
(2) My brother likes Greek food more than my sister likes Greek food.

Because the verb phrase is simple and short, we could simply add the word "does": My brother likes Greek food more than my sister does.

Now we are using does to stand in for "likes Greek food" and clear up any confusion.

The verb do can stand in for almost any verb in English.

When we use do in this way, we are not using pure ellipsis (omission). We are using ellipsis and substitution.

Substitution -- omission and replacement of words

When we use substitution, we replace a word or an entire phrase in one part of a sentence by a shorter "filler" word or phrase in another part of the sentence.

These shortened words or phrases "stand in" for the omitted words.

→ Nouns
We can shorten sentences by using noun ("nominal") substitution, this way:
The weekly ROI meeting was scheduled at midday and disrupted the whole workday, so we should schedule the next one early in the day.
The noun "one" = the weekly financial strategy meeting

→ Verbs

-- My brother got married before my sister got married.
==>>
-- My brother got
married before my sister did..
-- did = got married

→ Special substitution: do and do so

We can use the verb do (does, did, etc.) to substitute for almost any verb.*
-- She walks faster than I do.

Along similar lines, do so can stand in for almost any verb phrase.
-- When Lisa hired me to review her essay, she asked me to edit her work exactly as I edit professional writing, and I did so.
-- did so = edited her work exactly as I edit professional writing

Had?
Can we use "had" as a stand in verb?

No. We can repeat the auxiliary verb had and omit the main verb, but in that case, we are not substituting. We are omitting. This construction is rare on the GMAT and often inverted in the second clause.
-- By the end of WWII, the Soviet Union had lost more than 20 million people, as had only one other country--China.
-- had = lost more than 20 million people

Past perfect
Past perfect is often described as "the past of the past."

Event ABC happened in the past.
Before event ABC, event XYZ happened.

long time ago__|XYZ|___|ABC|__now

Event ABC takes the simple past verb tense.
Event XYZ takes the past perfect verb tense.

→ past perfect construction: HAD + past participle (verbED)
→ Correct: Luckily, as I pulled out of the driveway, I remembered that I had forgotten to lock the door.

→ We do not use past perfect when simple past tense will suffice.

→ Finally, in order to use past perfect, the sentence must contain at least one event that is rendered in simple past, or a time stamp that marks off a later-in-time event, or a context that does the same thing.

We need a discrete past that is "marked off in time" in order to talk about what came before that time.

AS

KaramveerBakshi , in answer to your question, first

→ As is not always followed by a clause.
Role: She went to the Halloween party dressed as Neytiri from Avatar.
Equals: Though we are not related, I think of her as my sister.
Stage: As a teenager, he contracted chicken pox.

→ We can omit verbs and the implied verbs are still "there," as are the clauses

On this point, I am going to quote Mike McGarry, because he gets away with a lot more snark than I do, at least for now:



KaramveerBakshi , I'm glad that you brought up the issue. I'd bet that other people had the same question.

In option A, this as IS followed by a clause. The verb in that clause, existed, is implied; existed is "there" but hidden.

SUGGESTION

Parallelism, ellipsis, and substitution can be challenging.

I suggest that most or all of you read two of Mike McGarry's blog posts. Three minutes each. (Okay. I read quickly. Ten minutes each.)

(1) Dropping Common Words in Parallel on the GMAT, which you can find here, and

(2) Repeating Verb Phrases on the GMAT, which you can find here.

COMMENTS

harrywm , daniformic , and Babineaux , welcome to SC Butler.

As always, I am glad to see everyone.

Random facts:
Today is the International Day of the World's Indigenous Peoples.
Today is also National Book Lovers Day in the U.S.
I think yesterday was National Beer Day. I don't like beer. I've tried to like beer.
I do like books. A lot. I don't have to try, either.

So, my nascent bibliophiles, I am going to remind you all yet again: read. Every day. Find 10 minutes.
Read novels. Read the highbrow stuff, but read books with great stories in them, too.

Love the task.
Or learn to love the task.
Reading? Learning? Perhaps the task even becomes a labor of love.

This SC question?
Labeling (e.g. "pronoun error") is not explanation. Assertion (e.g. "not correct") is not explanation.
Kudos go to those who reasoned well, got the correct answer, or both—and who also explained.
This question is hard. Nicely done.

*The verb "do" (does, did, etc.) cannot act as a substitute for
(1) to be verbs
Wrong: I was learning French, and he did, too.
Correct: I was learning French, and he was, too.
Correct: I was learning French, as was he.

(2) to have when have is a helping verb (i.e., when have does not mean "owned, possessed, or experienced")
Wrong: By the time dessert arrived, I had eaten too much, and he did, too.
Correct: By the time dessert arrived, I had eaten too much, and he had, too.
Correct: By the time dessert arrived, I had eaten too much, as had he.
Correct but not likely to be seen on the GMAT: I had plenty of Euros, and he did, too. (We can use "did" in this case because had is not an auxiliary verb. Rather, had is a main verb that means "possessed.")