Paleontologist Stephen Jay Gould has argued that many biological traits are not the products of natural selection, favored due to their enhancement of reproduction or survival, but that they are simply random by-products of other evolutionary developments.

(A) due to their enhancement of reproduction or survival, but that they are

(B) due to the reproduction or survival they enhance, but they are

(C) because they enhance reproduction or survival, but

(D) because they enhance reproduction or survival, but are

(E) because of enhancing reproduction or survival, but are

I am not clear why the answer is D. "~are not ~, but are~" doesn't seem parallel. Rather, "~are not ~, but ~" in C seems better. Thank you.

Good question.

Your first thought here probably was - and should be - parallelism. However, you're right that 'are not ... but are' and 'are not ... but' would both be legitimately parallel constructions in this context. So, the reasoning goes, we should take the one with one fewer word. Right?

Here's the problem: In the context of this longer, more complicated sentence, the 'but' (without 'are' after it) is, unfortunately, ambiguous. Consider this sentence:
Jimmy was not the typical class president, loved by most of the students, but hated by a fair number as well.
The most probable reading here is that all of the words 'loved by most of the students, but also hated by a fair number as well' are a description of 'the typical class president.' However, it's also possible that just "loved by most of the students" describes that phrase. So there are 2 interpretations:
1) Jimmy was not the typical class president, loved by most of the students, but hated by a fair number as well. --> in which the entire colored description attaches to “the typical class president”
2) Jimmy was not the typical class president, loved by most of the students, but hated by a fair number as well. --> in which “the typical class president” is described as someone who is loved by most students; in this instance, jimmy is contrasted with the typical class president because some people also hate him.

If you look at choice C, it can be read this way; one could (probably should, even) take ALL the words '...favored because they enhance reproduction or survival, but simply random byproducts...' as an elaboration on the phrase 'products of natural selection'.
It's harder to see than in the example of Jimmy, above, for two reasons:
(1) Because of the way the original sentence is written, you're biased toward reading the sentence the way it's 'supposed' to be written. (In the example with Jimmy, there's no prompt sentence, so you're free to read it as you like.)
(2) It's longer.

Hope this helps.

I still don't get how C is wrong?

Paleontologist Stephen Jay Gould has argued that many biological traits are not the products of natural selection, favored because they enhance reproduction or survival, but simply random by-products of other evolutionary developments.


I still think C is correct.

there are two ways of reading the sentence if choice c is inserted. here they are, with the boldface in each indicating exactly what is construed as a modifier:

1) Paleontologist Stephen Jay Gould has argued that many biological traits are not the products of natural selection, favored because they enhance reproduction or survival, but simply random by-products of other evolutionary developments. --> this is the most obvious reading

2) Paleontologist Stephen Jay Gould has argued that many biological traits are not the products of natural selection, favored because they enhance reproduction or survival, but simply random by-products of other evolutionary developments. --> counterintuitive if you know anything about evolutionary biology, but grammatically ok -- and therefore a competing interpretation, which is fatal to clarity.

remember two things.
a -- you are not allowed to use 'common sense' to resolve the meaning of a sentence. if there are two grammatically acceptable interpretations, then it's a bad sentence. period. whether one interpretation is more realistic matters not.
b -- most importantly, the gmat is the 'native speaker'. what it says goes, and that's simply the end of it. if you still like choice c better than choice d, you have two options left:
first option: accept the fact that the gmat disagrees with you, give in, and get analogous problems correct when you encounter them.
second option: continue to resist the gmat's version of correct english, fight an uphill battle, and get problems wrong.
pick your poison.

with that said, please don't hesitate to criticize our problems. we always strive to better our materials, and have the utmost gratitude for your feedback.

--

and as for bumping this thread after two months' inactivity... impressive!

Ron: Sorry to continue on this topic in spite of your lengthy explanations above but I am just not getting it - how is the reading of your sentence 2 above different from the reading of your sentence 1 above? Don't both of them mean exactly the same?

Similarly in your following example:

Jimmy was not the typical class president, loved by most of the students, but also hated by a fair number as well; rather, he was loved by all the students.
The most probable reading here is that all of the words 'loved by most of the students, but also hated by a fair number as well' are a description of 'the typical class president.'

What is the other reading? Thanks a lot. This is one tough question to understand. Hopefully, it will click soon.

I'll give a try here, though Ron, feel free to clarify. Look at the possible structures:

Ron's first example can be read as:
SJG has argued that many bio traits are not X [the products...selection], modifier of X [favored...survival], but simply Y [random...developments].

So, above, I'm contrasting X and Y, and X also happens to have a little extra modifier going on.

Ron's second example can be read as:
SJG has argued that many bio traits are not X [the products...selection], modifier of X [favored...survival], modifer of modifier of X [but simply...developments].

In other words, I'm no longer contrasting X and Y - instead, I'm saying something about X and then giving a couple of modifiers in a row to describe it - there is no longer a comparable, contrasting Y. (And, yes, as Ron points out, this doesn't make logical sense if you know anything about the topic. But it is a grammatical possibility - someone who didn't know that this is illogical couldn't be sure that this isn't the meaning.)

I need that "are" in there to know that it is definitely option 1: comparing X to Y. Bio traits are not X but are Y.

_________________
Stacey Koprince
Instructor
Director of Online Community
ManhattanGMAT

BUt in choice "A" you also have are -->"but that they are" So why "but that they are .." can be interpreted as modifier of "X" and in choice "D" this is not the case? Can we treat some thing starting with "but.." as modifier or it has to show contrast?

i think the fatal aspect of choice a is its excessive wordiness.

to wit:
'due to their enhancement of reproduction or survival', from a, vs. 'because they enhance reproduction or survival', from d --> d wins
'but that they are' from a, vs. 'but are' from d --> d wins

since those two examples seem to be decent on all other fronts, we make our decision based on concision. in that case, d is a clear winner over a.

Great explanations folks. From what I am seeing is that D is a more text book safer version of the paralells.

Side note: is there a way to use the differences of "due to" and "because of" here?

you can use "due to" and "because of" in any sentence - you just have to structure the sentence correctly around this phrase. This is a bit of a red herring here - they're trying to get you to spend time deciding based on those two sets of words rather than base the decision on what you should be basing it on.

_________________
Stacey Koprince
Instructor
Director of Online Community
ManhattanGMAT

Hi Guys

Can someone please explain why choice E is wrong ... ???

Thanks
Sputnik

'because of enhancing' = incorrect idiom
not only is this an incorrect idiom, but it also eliminates any reference as to exactly what enhances reproduction or survival.

What does "favored" in this question modify? the products of natural selection? natural selection? many biological traits? or the preceding "that" clause?

A more general question:
S+V+O, verb-ed...
What does "verb-ed" modify?

Is there a rule?

Thanks.

in that sort of construction, the past participial modifier (the thing starting with "verb-ed") is normally taken to modify the closest noun. in the construction you've drawn up, that noun would be the object.

if you want the construction to modify the subject instead, you should insert it into the main clause right after the subject, using commas to set it off:
"S, verb-ed by blah blah blah, V+O."

Is it correct that their in A is ambiguous, can refer to biological traits or products of natural selection?

But they is not because it's parallel to biological traits (and so also refering to biological traits)