Bat wings - OG difficult - method of reasoning

This topic has expert replies
Master | Next Rank: 500 Posts
Posts: 152
Joined: Mon Feb 20, 2012 12:56 pm
Location: New york
Thanked: 9 times
Networks of blood vessels in bats' wings serve only to disperse heat generated in flight. This heat is generated only because bats flap their wings. Thus aleontologists' recent discovery that the winged dinosaur Sandactylus had similar networks of blood vessels in the skin of its wings provides evidence for the hypothesis that Sandactylus flew by flapping its wings, not just by gliding.

In the passage, the author develops the argument by
(A) forming the hypothesis that best explains several apparently conflicting pieces of evidence
(B) reinterpreting evidence that had been used to support an earlier theory
(C) using an analogy with a known phenomenon to draw a conclusion about an unknown phenomenon
(D) speculating about how structures observed in present-day creatures might have developed from similar structures in creatures now extinct
(E) pointing out differences in the physiological demands that flight makes on large, as opposed to small, creatures


OA is C
I dont understand what analogy are we using with a known phenomenon..

User avatar
GMAT Instructor
Posts: 1248
Joined: Thu Mar 29, 2012 2:57 pm
Location: Everywhere
Thanked: 503 times
Followed by:192 members
GMAT Score:780

by Bill@VeritasPrep » Tue Apr 10, 2012 6:07 pm
I don't particularly like C either, but the other answers are all worse.

A--We don't have several apparently conflicting pieces of evidence.
B--There is no reinterpretation of evidence that led to an earlier theory.
D--There is nothing about the bats' wings blood vessel networks developing from those of Sandactlyus
E--There is no comparison between large and small flying creatures.

C definitely uses a known phenomenon (bats) to draw a conclusion about an unknown phenomenon (Sandactylus), but I wouldn't call it an analogy.
Join Veritas Prep's 2010 Instructor of the Year, Matt Douglas for GMATT Mondays

Visit the Veritas Prep Blog

Try the FREE Veritas Prep Practice Test

Newbie | Next Rank: 10 Posts
Posts: 4
Joined: Thu Apr 05, 2012 10:11 am

by jerryzheng » Tue Apr 10, 2012 6:08 pm
agarwalva wrote:Networks of blood vessels in bats' wings serve only to disperse heat generated in flight. This heat is generated only because bats flap their wings. Thus aleontologists' recent discovery that the winged dinosaur Sandactylus had similar networks of blood vessels in the skin of its wings provides evidence for the hypothesis that Sandactylus flew by flapping its wings, not just by gliding.

In the passage, the author develops the argument by
(A) forming the hypothesis that best explains several apparently conflicting pieces of evidence
(B) reinterpreting evidence that had been used to support an earlier theory
(C) using an analogy with a known phenomenon to draw a conclusion about an unknown phenomenon
(D) speculating about how structures observed in present-day creatures might have developed from similar structures in creatures now extinct
(E) pointing out differences in the physiological demands that flight makes on large, as opposed to small, creatures


OA is C
I dont understand what analogy are we using with a known phenomenon..
the known phenomenon refers to the networks of blood vessels in bat wings. It's told that the networks serve only to disperse the heat generated during flapping, thus the author infers that Sandactylus, which have the similar network of blood vessels, should also flap during flight.

User avatar
Legendary Member
Posts: 934
Joined: Tue Nov 09, 2010 5:16 am
Location: AAMCHI MUMBAI LOCAL
Thanked: 63 times
Followed by:14 members

by [email protected] » Wed Apr 11, 2012 12:13 am
Networks of blood vessels in bats' wings serve only to disperse heat generated in flight. This heat is generated only because bats flap their wings. Thus aleontologists' recent discovery that the winged dinosaur Sandactylus had similar networks of blood vessels in the skin of its wings provides evidence for the hypothesis that Sandactylus flew by flapping its wings, not just by gliding.


In the passage, the author develops the argument by
(A) forming the hypothesis that best explains several apparently conflicting pieces of evidence
(B) reinterpreting evidence that had been used to support an earlier theory
(C) using an analogy with a known phenomenon to draw a conclusion about an unknown phenomenon
(D) speculating about how structures observed in present-day creatures might have developed from similar structures in creatures now extinct
(E) pointing out differences in the physiological demands that flight makes on large, as opposed to small, creatures



These sort of CRs are very useful not only for the CR section in the GMAT but also for the RC section in the GMAT. The RC section ask a lot of tone and author's perspective questions.

The logical structure and argument question types are also asked in the RC section. You would come to know this when you solve the RC section from the OG...

Even few of LSAT CRs are helpful for making you ready for the RC section in the GMAT....

I hope this post helps you guyzzz...
IT IS TIME TO BEAT THE GMAT

LEARNING, APPLICATION AND TIMING IS THE FACT OF GMAT AND LIFE AS WELL... KEEP PLAYING!!!

Whenever you feel that my post really helped you to learn something new, please press on the 'THANK' button.

User avatar
Legendary Member
Posts: 626
Joined: Fri Dec 23, 2011 2:50 am
Location: Ahmedabad
Thanked: 31 times
Followed by:10 members

by ronnie1985 » Wed Apr 11, 2012 9:55 am
(C) bats wings dissipate heat due to flapping action hence the dinosaurs used to flap and hence fly...
Follow your passion, Success as perceived by others shall follow you