Bird feathers appear to have evolved from dinosaur...

[davaronio]

Hi, I just took an 800Score.com CAT and got an SC question that reminded me of an SC question we went over in MGMAT class. I went with what I thought was the best answer but 800Score.com says I'm wrong.

Can someone please help me understand where my understanding of modification is used is wrong in this case?

HERE IS THE QUESTION FROM 800SCORE.COM:
Bird feathers appear to have evolved from dinosaur scales well over 100 million years ago, Chinese scientists have shown, based on a fossil bird found in the Yixian mountains of northern China.

A. Bird feathers appear to have evolved from dinosaur scales well over 100 million years ago, Chinese scientists have shown, based on a fossil bird found in the Yixian mountains of northern China.

B. Chinese scientists, having shown that bird feathers appear to have evolved from dinosaur scales well over 100 million years ago, based on a fossil bird found in the Yixian mountains of northern China.

C. Based on a fossil bird found in the Yixian mountains of northern China, Chiense scientists showed that bird feathers have appeared to have evolved from dinosaur scales well over 100 million years ago.

D. When a fossil bird in the Yixian mountains of northern China was found well over 100 million years ago, Chinese scientists showed that bird feathers appear to have evolved from dinosaur scales

E. Based on a fossil bird found in the Yixian mountains of northern China, Chinese scientists have shown that bird feathers appear to have evolved from dinosaur scales well over 100 million years ago.

800Score.com's OA: E

While I knew E looked good, I chose A because this SC question reminded me of an OG question from the 12th edition, on page 697:

HERE IS QUESTION 25 FROM OG 12:

[deleted because problem is from a banned source - see below]

[tim]

OG is a banned source; it is illegal to post OG questions anywhere on the web. If you are in one of our classes, please ask OG questions during office hours or before/after class..

Take a closer look at that OG problem you referred to though; it's not as similar to A as you thought. 800score got it right this time..

[davaronio]

OG is a banned source; it is illegal to post OG questions anywhere on the web. If you are in one of our classes, please ask OG questions during office hours or before/after class..

Take a closer look at that OG problem you referred to though; it's not as similar to A as you thought. 800score got it right this time..

Hi Tim, sorry, I don't know what I was thinking when I posted the OG problem - I wasn't!

Choice A of 800Score.com is indeed different from Choice A of Question 25 in OG 12 ("Based on accounts of various..."). But, what I have not been able to figure out is, why is 800Score.com's Choice E is the right answer?

800Score.com's Choice E: "Based on a fossil bird found in the Yixian mountains of northern China, Chinese scientists have shown that bird feathers appear to have evolved from dinosaur scales well over 100 million years ago."

Doesn't this sentence, supposedly the correct answer according to 800Score.com, violate the principle explained in the OG's official explanation? Isn't "Based on a fossil bird found..." a modifier, which is describing the noun that immediately follows it, which in this case are the "Chinese scholars"?

By the way, my class already finished... Thank you in advance for any light you can shed.

[tim]

The phrase "based on ..." is not a noun modifier; it is an adverbial modifier. Thus it does not have to touch anything in particular to be correct..

[davaronio]

The phrase "based on ..." is not a noun modifier; it is an adverbial modifier. Thus it does not have to touch anything in particular to be correct..

Ok... Then, can you please help me understand how 800Score.com's "Based on..." is different from the OG's "Based on..."? They both look the same to me, but one is used correctly and the other is not.

Thank you so much, Tim.

[tim]

Ah, you're totally right, i was focusing on 800score's A rather than their E since that's the one you picked. Yes they correctly eliminated A, but i didn't notice that they also failed to eliminate E. After an exhaustive search through the OG, i find that they NEVER use "based on" at the beginning of a sentence as an adverbial modifier (even though in "real life" it is okay in certain contexts)..

So you're probably safe to use that as a general rule (in which case 800score's E is wrong), but the real reason both A in the OG and E in 800score are wrong is this: Even giving the sentence the benefit of the doubt - i.e. allowing "based on" to be an adverbial modifier - neither example makes sense when we apply "based on" as a modifier of the verb or clause..

It makes no more sense to paint something based on accounts (OG) than it does to show something based a fossil bird. So the sentences as given don't make sense regardless of whether "based on" is an adverbial or noun modifier. i should have known something was up when i concluded originally that their problem was fine.. :)