Last visit was: 19 Nov 2025, 07:18 It is currently 19 Nov 2025, 07:18
Home
GMAT
Messages
Tests
Schools
Events
Rewards
Chat
My Profile
Close
GMAT Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel
Back to Forum
Create Topic
   1   2   3   
User avatar
theclueless
User avatar
Joined: 17 Nov 2010
Last visit: 02 Oct 2025
Posts: 9
Posts: 9
Kudos: 0
Knewton Challenge: Win Knewton Shirt and GMAT Club Tests 01 Sep 2011, 22:42
Kudos
Add Kudos
Bookmarks
Bookmark this Post
The answer is B . Since it is implied that fore limbs were more important than hind limbs for entering into the mother's pouch for further development.
User avatar
srinivaasganesan
User avatar
Joined: 13 Aug 2011
Last visit: 01 Apr 2016
Posts: 4
Given Kudos: 2
Posts: 4
Kudos: 0
Knewton Challenge: Win Knewton Shirt and GMAT Club Tests 01 Sep 2011, 22:45
Kudos
Add Kudos
Bookmarks
Bookmark this Post
E.
The finding is that lions had only their forelimbs developed.
To say that they also climbed to mother's pouches relies on the assumption
E ie.,forelimbs had grown to help them in the process of climbing to their mother's pouch.
avatar
Shivani2koul
avatar
Joined: 04 Mar 2011
Last visit: 22 Sep 2011
Posts: 2
Posts: 2
Kudos: 0
Knewton Challenge: Win Knewton Shirt and GMAT Club Tests 02 Sep 2011, 00:45
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Ans is D
[D] Newborn marsupial lions that crawled into their mothers’ pouches could not have done so had they not had only their forelimbs developed at birth.
avatar
Shivani2koul
avatar
Joined: 04 Mar 2011
Last visit: 22 Sep 2011
Posts: 2
Posts: 2
Kudos: 0
Knewton Challenge: Win Knewton Shirt and GMAT Club Tests 02 Sep 2011, 00:46
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Ans
[D] Newborn marsupial lions that crawled into their mothers’ pouches could not have done so had they not had only their forelimbs developed at birth.
avatar
onroll
avatar
Joined: 21 Aug 2011
Last visit: 02 Sep 2011
Posts: 1
Posts: 1
Kudos: 0
Knewton Challenge: Win Knewton Shirt and GMAT Club Tests 02 Sep 2011, 01:50
Kudos
Add Kudos
Bookmarks
Bookmark this Post
D. Newborn marsupial lions that crawled into their mothers’ pouches could not have done so had they not had only their forelimbs developed at birth.
The fact that Joey's forelimbs being well developed, help him to climb from the cloaca into its mother’s pouch for further development. Along with it, it has been recently discovered that marsupial lions were also found to have forelimbs at the time of birth. So, forelimbs are a prerequisite for newborns to climb the pouch. This means, that the newborn marsupials would not be able to climb if they didn't had forelimbs developed at the time of their birth.
User avatar
karan2483
User avatar
Joined: 01 Oct 2010
Last visit: 24 Oct 2013
Posts: 2
Own Kudos:
12
Given Kudos: 1
Posts: 2
Kudos: 12
Knewton Challenge: Win Knewton Shirt and GMAT Club Tests 02 Sep 2011, 03:03
Kudos
Add Kudos
Bookmarks
Bookmark this Post
A newborn kangaroo, or joey, is born after a short gestation period of only 39 days. At this stage, the joey’s hind limbs are not well developed, but its forelimbs are well developed, so that it can can climb from the cloaca into its mother’s pouch for further development. The recent discovery that ancient marsupial lions were also born with only their forelimbs developed supports the hypothesis that newborn marsupial lions must also have needed to climb into their mothers’ pouches.

The argument in this passage relies on which of the following assumptions?

[A] All animals that are born after a short gestation period are born with some parts of their bodies underdeveloped.
Well developed forelimbs would have been more advantageous to ancient marsupial lions than well developed hind limbs would have been.
[C] If the newborn marsupial lion did not climb into its mother’s pouch, then paleontologists would be able to find evidence of this fact.
[D] Newborn marsupial lions that crawled into their mothers’ pouches could not have done so had they not had only their forelimbs developed at birth.
[E] Newborn marsupial lions would not have had only their forelimbs developed if this development were of no use to the marsupial lion


The correct answer is E

The answer choice A is completely irreleavant as it talks about the gestaion period of the animals and the answer passage mentins nothing about the gestaation perod of marsupial lion.

Answer choice B compares well developed forelimbs as compared to hind limbs, where as hypothesis that newborn marsupial lions must also have needed to climb into their mothers’ pouches based on the fact that they have well developed forelimbs.

Answer Choice C is off tpoic as it states If the newborn marsupial lion did not climb into its mother’s pouch, then paleontologists would be able to find evidence of this fact, wheras the hypothesis that since they have well developed forelimbs they muist have needed to climb into there mother's pouches.

Answer Choice D seems very tempting but again be very careful as it states that marsupial lions that climb into their mother's pouches could not have done so without the well developed forelimbs remember that the hypothesesis is that since they have strong foelimbs they must have needed to climb in their mother's pouch. See the cause and effect relationship that the statement is giving.

SO cleary the answer choice E is correct since the have strong forelimbs they must have been for the reason-that is to climb in their mother's pouch just as joey uses them to climb.

Hope the answer and explanation is correct looking forward for the correct answer.
avatar
bficcade
avatar
Joined: 25 Jul 2011
Last visit: 17 Jan 2014
Posts: 1
Posts: 1
Kudos: 0
Knewton Challenge: Win Knewton Shirt and GMAT Club Tests 02 Sep 2011, 03:16
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Hello. This is my first time posting on GMATClub (or any forum for that matter), and I have only just started studying for the GMAT, but here it goes:

In this critical reasoning passage the author sets up a parallel logic between joeys and marsupial lions.

The base logic can be found in the following sentence:

"At this stage, the joey’s hind limbs are not well developed, but its forelimbs are well developed, so that it can can climb from the cloaca into its mother’s pouch for further development."

where, the prepositional phrase so that indicates that there exists a reason, a developmental significance, why the joeys are born with only well-developed forelimbs.

The parallel logic can then be understood as follows:

if:
when "a joey" is born with "only well-developed forelimbs", it is for the purpose of "climbing into the mother's pouch"
then:
when "a marsupial lion" is born with "only well-developed forelimbs" it must be for the purpose of "climbing into the mother's pouch"

The assumption in this line of logic is that if the well-developed forelimbs of the joeys have a purpose, or use, than the same developmental feature in the marsupial lions must also have a similar purpose.

Thus, the answer is [E] Newborn marsupial lions would not have had only their forelimbs developed if this development were of no use to the marsupial lions.

Hope that is clear! (and correct!)
User avatar
mourinhogmat1
User avatar
Joined: 08 Jun 2010
Last visit: 11 Aug 2015
Posts: 213
Own Kudos:
199
 [1]
Given Kudos: 13
Location: United States
Concentration: General Management, Finance
Schools: Darden '15 (D) Wharton '15 (D) Johnson '15 (S)
GMAT 1: 680 Q50 V32
Schools: Darden '15 (D) Wharton '15 (D) Johnson '15 (S)
GMAT 1: 680 Q50 V32
Posts: 213
Kudos: 199
 [1]
Knewton Challenge: Win Knewton Shirt and GMAT Club Tests 02 Sep 2011, 03:56
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
A newborn kangaroo, or joey, is born after a short gestation period of only 39 days. At this stage, the joey’s hind limbs are not well developed, but its forelimbs are well developed, so that it can can climb from the cloaca into its mother’s pouch for further development. The recent discovery that ancient marsupial lions were also born with only their forelimbs developed supports the hypothesis that newborn marsupial lions must also have needed to climb into their mothers’ pouches.

The argument in this passage relies on which of the following assumptions?

[A] All animals that are born after a short gestation period are born with some parts of their bodies underdeveloped.
[B] Well developed forelimbs would have been more advantageous to ancient marsupial lions than well developed hind limbs would have been.
[C] If the newborn marsupial lion did not climb into its mother’s pouch, then paleontologists would be able to find evidence of this fact.
[D] Newborn marsupial lions that crawled into their mothers’ pouches could not have done so had they not had only their forelimbs developed at birth.
[E] Newborn marsupial lions would not have had only their forelimbs developed if this development were of no use to the marsupial lions.


Evidence 1: For a new Kangaroo gestation period = 39days (SHORT GESTATION)
Evidence 2: Hind limbs are not well developed but Fore limbs are well developed. Why?
Evidence 3: So, that they can climb in to the pouch (Key word is So, that)
Main Conclusion: The evidence found in the lions strengthens the conclusion that developed forelimbs meant that they used this for climbing into the pouch of the adult lion.

Assumption should Eliminate a possibility of use of the fore limb or suggest some similiarity between Lions and Kangaroos.

A) INCORRECT. A addresses an assumption for Evidence 1, which is in fact irrelevant to the argument
B) INCORRECT. This highlights a relative comparison between the two limbs which is outside the scope of this argument.
C) INCORRECT. Outside the scope of this argument as well. Because it refers to a hypothetical possibility not relating to the evidence or the conclusion.
D) INCORRECT. This is the correct "wrong" answer. In fact this question talks about the possibility of not only this hind limbs. This statement talks about Fore limbs being the ONLY reason for the climbing. In fact this aspect of the argument is not discussed here. We only wish to know if the presence of a fore limb strengthens the fact that fore limbs are present for climbing into the pouch.
E) CORRECT. Try the negative test to confirm the answer: Newborn marsupial lions would not have had only their forelimbs developed if this development were used by the marsupial lions. This is also the only answer which connects the new born marsupials to the EVIDENCE OF ANCIENT MARSUPIALS (which maybe adults or young ones).
avatar
HBSEntrant
avatar
Joined: 27 Jun 2009
Last visit: 15 Nov 2013
Posts: 5
Own Kudos:
6
Schools: ESADE '15 (D) NUS '15 (D) Said IE '15 (A) ISB '14 (D) Insead '13 (D)
GMAT 2: 680 Q50 V33
Posts: 5
Kudos: 6
Knewton Challenge: Win Knewton Shirt and GMAT Club Tests 02 Sep 2011, 04:36
Kudos
Add Kudos
Bookmarks
Bookmark this Post
The Answer is D.

It is assumed that due to well developed forelimb only marsupial lions could climb to their Mother's lap.
avatar
subhajeet
avatar
Joined: 12 Jun 2010
Last visit: 11 Feb 2013
Posts: 77
Own Kudos:
255
Given Kudos: 1
Status:MBA Aspirant
Location: India
Concentration: Finance, International Business
WE:Information Technology (Finance: Investment Banking)
Posts: 77
Kudos: 255
Knewton Challenge: Win Knewton Shirt and GMAT Club Tests 02 Sep 2011, 06:24
Kudos
Add Kudos
Bookmarks
Bookmark this Post
I think the answer must be "A"

[A] All animals that are born after a short gestation period are born with some parts of their bodies underdeveloped.
Clearly supports the hypothesis. Since body parts are not completely developed, so it will need to climb into its mother's pouch to get developed.
[B] Well developed forelimbs would have been more advantageous to ancient marsupial lions than well developed hind limbs would have been.
NO relation to the hypothesis
[C] If the newborn marsupial lion did not climb into its mother’s pouch, then paleontologists would be able to find evidence of this fact.
No mention of paleontologists in the discussion
[D] Newborn marsupial lions that crawled into their mothers’ pouches could not have done so had they not had only their forelimbs developed at birth.
Not only forelimbs development is needed.
[E] Newborn marsupial lions would not have had only their forelimbs developed if this development were of no use to the marsupial lions.
out of scope
avatar
abidshariff
avatar
Joined: 09 Mar 2011
Last visit: 07 Mar 2013
Posts: 4
Given Kudos: 1
Posts: 4
Kudos: 0
Knewton Challenge: Win Knewton Shirt and GMAT Club Tests 02 Sep 2011, 08:37
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Que:A newborn kangaroo, or joey, is born after a short gestation period of only 39 days. At this stage, the joey’s hind limbs are not well developed, but its forelimbs are well developed, so that it can can climb from the cloaca into its mother’s pouch for further development. The recent discovery that ancient marsupial lions were also born with only their forelimbs developed supports the hypothesis that newborn marsupial lions must also have needed to climb into their mothers’ pouches.

Ans:
The ancient marsupial lions were also born with only their forelimbs developed .So the conclusion is that the newborn marsupial lions must also have needed to climb into their mothers’ pouches for further development.

[A] All animals that are born after a short gestation period are born with some parts of their bodies underdeveloped.--All animals!!!!!...Come on..I'm just talking about kangaroos and lions.
[b] Well developed forelimbs would have been more advantageous to ancient marsupial lions than well developed hind limbs would have been.--Hind limbs were never mentioned in the passage
[C] If the newborn marsupial lion did not climb into its mother’s pouch, then paleontologists would be able to find evidence of this fact.--May be true, but this is not tied to the conclusion of the passage
[D] Newborn marsupial lions that crawled into their mothers’ pouches could not have done so had they not had only their forelimbs developed at birth.--Look closely at the conclusion. It says that the lions must also have needed to climb. Had the conclusion been "The lions have climbed because they have had only their forelimbs developed at birth", then this option could have been a strong contender.
[E] Newborn marsupial lions would not have had only their forelimbs developed if this development were of no use to the marsupial lions--PERFECT!!..Look at the conclusion again.."The lions must also have needed to climb". So the author here is saying that the lions have had only their forelimbs developed at birth and assuming that this development is of some use to them(in this case to climb onto their mothers' pouches). For better understanding, try negating the statement. "The the lions would have had only their forelimbs developed even if this development were of no use". In other words, this development is useless, so this development might not have been useful in climbing onto their mothers' pouches. So the author's conclusion is weakened comprehensively.

So I guess it has to be E
avatar
navs47
avatar
Joined: 06 Sep 2010
Last visit: 01 Mar 2015
Posts: 1
Given Kudos: 1
Posts: 1
Kudos: 0
Knewton Challenge: Win Knewton Shirt and GMAT Club Tests 02 Sep 2011, 10:31
Kudos
Add Kudos
Bookmarks
Bookmark this Post
The answer is E. Explanation below:

Refer to: "The recent discovery that ancient marsupial lions were also born with only their forelimbs developed supports the hypothesis that newborn marsupial lions must also have needed to climb into their mothers’ pouches."

The above hypothesis suggests IF the marsupial lions didn't NEED TO CLIMB into their mother's pouches, they would not have had only their forelimbs developed in the first place, which is reiterated in option E.

N
avatar
sl750
avatar
Joined: 07 Jun 2011
Last visit: 19 Dec 2011
Posts: 7
Given Kudos: 1
Posts: 7
Kudos: 0
Knewton Challenge: Win Knewton Shirt and GMAT Club Tests 02 Sep 2011, 11:00
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Answer is E
If this assumption were not true, the hypothesis that Marsupial Lions must also have needed to climb into their mothers’ pouches would not hold. The argument's assumption hinges on the fact that development of the forelimbs in the newborn Lions served a certain purpose, i.e, it helped aid the newborn to climb into it's mother's pouch
avatar
sb1
avatar
Joined: 05 Jul 2011
Last visit: 27 Dec 2015
Posts: 2
Own Kudos:
11
Posts: 2
Kudos: 11
Knewton Challenge: Win Knewton Shirt and GMAT Club Tests 02 Sep 2011, 11:09
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Answer is (E).

A - Bad Generalization
B - Again a Bad Generalization.
C - New Info.
D - looks like a good answer choice but there is bad generalization here too "only forelimbs".
avatar
priyachandrasekhar
avatar
Joined: 02 Sep 2011
Last visit: 05 Nov 2011
Posts: 1
Posts: 1
Kudos: 0
Knewton Challenge: Win Knewton Shirt and GMAT Club Tests 02 Sep 2011, 11:36
Kudos
Add Kudos
Bookmarks
Bookmark this Post
A newborn kangaroo, or joey, is born after a short gestation period of only 39 days. At this stage, the joey’s hind limbs are not well developed, but its forelimbs are well developed, so that it can can climb from the cloaca into its mother’s pouch for further development. The recent discovery that ancient marsupial lions were also born with only their forelimbs developed supports the hypothesis that newborn marsupial lions must also have needed to climb into their mothers’ pouches.

Answer : Option D

The passage shows an analogy between the development of forelimbs in newborn kangaroo and marsupial lions. It suggests that in kangaroos, the forelimbs helped the newborn to get into the mother's pouch. And it supports the hypothesis that newborn marsupial lions must also have needed to climb into their mothers’ pouches by showing the recent discovery of ancient marsupial lions being born with only their forelimbs developed. This clearly leads us to the assumption that forelimbs were necessary for the newborn marsupial lions to crawl into the mother's pouch.

Which is option D.

We can arrive at the answer even by eliminating the choices.

[A] All animals that are born after a short gestation period are born with some parts of their bodies underdeveloped - This is not dealing with the main point of the need of the newborn to crawl into the mother's pouch.

[B] Well developed forelimbs would have been more advantageous to ancient marsupial lions than well developed hind limbs would have been - The comparison made here is wrong because the newborn marsupial lions have ONLY developed forelimbs and NO hindlimbs.

[C] If the newborn marsupial lion did not climb into its mother’s pouch, then paleontologists would be able to find evidence of this fact - Let us attack this option in a different way. What if the new born marsupial lion died as soon it was born, before it could get into the mother's pouch. Paleontologists will now find the evidence that the newborn lion does not climb into the mothers' pouch. However this finding of theirs would be wrong.

[E] Newborn marsupial lions would not have had only their forelimbs developed if this development were of no use to the marsupial lions - This statement suggests that based on its use, an organ is developed. However, it is the opposite. Once an organ is developed, it is put to the best possible use.

[D] Newborn marsupial lions that crawled into their mothers’ pouches could not have done so had they not had only their forelimbs developed at birth - This option clearly tells that for climbing into the mothers' pouch, the newborn needed only their forelimbs developed at birth, thereby supporting the hypothesis - CORRECT ANSWER.

Please correct me if I am wrong.
avatar
JessieKnewton
avatar
Knewton GMAT Representative
Joined: 17 Aug 2011
Last visit: 06 Feb 2012
Posts: 26
Own Kudos:
30
Posts: 26
Kudos: 30
Knewton Challenge: Win Knewton Shirt and GMAT Club Tests 02 Sep 2011, 14:43
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Just so you all know - we'll be announcing the winner on Tuesday (you guys get an extra day to think, thanks to the holiday weekend)! Keep the answers coming!
avatar
utudas
avatar
Joined: 16 Jun 2011
Last visit: 18 Feb 2020
Posts: 10
Given Kudos: 3
Posts: 10
Kudos: 0
Knewton Challenge: Win Knewton Shirt and GMAT Club Tests 02 Sep 2011, 21:03
Kudos
Add Kudos
Bookmarks
Bookmark this Post
The answer is D
Following reason to strike out answers
1) There is no information about generalization of all animals. So choice A is not correct.
2) It is not stated in the passage regarding any advantage of forelimbs.Moreover, we don't know about well developed hindlimbs of marsupial lions. So choice B is not correct.
3) No information about paleontologists will find evedence. So choice C is not correct.
4) Development of forelimbs helped new born marsupial lions to climb into their mothes' pouches. If this assumption is true, it strongly follows passage conclusion. So choice D is correct.
5) Last option is quite far from assumption for passage conclusion. Forelimbs wouldn't have been developed if there was no use claims that there must have some use. But doesn't specify what use and how it supports the conclusion. So choice E is not correct.
avatar
prasrush2001
avatar
Joined: 15 Jan 2011
Last visit: 04 Feb 2012
Posts: 5
Given Kudos: 12
Posts: 5
Kudos: 0
Knewton Challenge: Win Knewton Shirt and GMAT Club Tests Updated on: 03 Sep 2011, 07:03
Originally posted by prasrush2001 on 02 Sep 2011, 21:25.
Last edited by prasrush2001 on 03 Sep 2011, 07:03, edited 1 time in total.
Kudos
Add Kudos
Bookmarks
Bookmark this Post
ASSUMPTION Question:

Passage Diagram:
Premise
Kangaroo: Hind limbs not well developed but forelimbs develops-->forelimbs used for climbing into mother's pouch for further development.
Conclusion
Marsupial Lion: Also born with forelimbs developed--> Must has needed to climb into their mother's pouch
Missing Link
Before looking at answer choices: Assumption should be something which shows need of forelimbs for nothing but climbing into their mother's pouch


Answer Choices:

[A] All animals that are born after a short gestation period are born with some parts of their bodies underdeveloped. (Does not mention anything about forelimbs and pouch)
[B] Well developed forelimbs would have been more advantageous to ancient marsupial lions than well developed hind limbs would have been. (Does not mention about need of forelimbs for nothing but pouch)
[C] If the newborn marsupial lion did not climb into its mother’s pouch, then paleontologists would be able to find evidence of this fact. (Does not mention anything about need of forelimbs)
[D] Newborn marsupial lions that crawled into their mothers’ pouches could not have done so had they not had only their forelimbs developed at birth. (Tempting- but it repeats conclusion)
[E] Newborn marsupial lions would not have had only their forelimbs developed if this development were of no use to the marsupial lions. (Left with E. Mentions about need of forelimbs)

Answer is E

Hope my answer is correct ..
User avatar
alicegmat
User avatar
Joined: 20 Apr 2011
Last visit: 15 Feb 2019
Posts: 56
Own Kudos:
208
Given Kudos: 41
Status:Mission GMAT
Posts: 56
Kudos: 208
Knewton Challenge: Win Knewton Shirt and GMAT Club Tests 03 Sep 2011, 05:08
Kudos
Add Kudos
Bookmarks
Bookmark this Post
In my opinion, the correct answer is E.

An assumption is what is absolutely necessary for the conclusion to hold. In other words, the assumption is the unstated premise of the argument. While there are several assumptions made in an argument (all of which have to be true), only one will be present in the answer choice. So, the trick to spot one is not to find the choice that validates the conclusion, but to find the choice that is an essential piece of information for the conclusion to be true. Also, along with supporting the conclusion, the assumption must also link the premises with the conclusion. Negating the assumption will destroy the argument.

The question asks for an assumption. Hence, the argument will consist of premises and conclusion.

Breaking down the argument structure as premises and conclusion, we have;

Premise 1: Joey (newborn kangaroo), born after a short gestation period of 39 days, (at birth) does not have well-developed hindlimbs However, Joey's forelimbs are well developed so that (i.e. the purpose of well developed forelimbs is that) Joey can climb from cloaca into its mother's pouch for further development.
Premise 2: The recent discovery is that ancient marsupial lions were also born with only their forelims developed.
Conclusion: This discovery (of ancient marsupial lions) supports the hypothesis that newborn marsupial lions must also have needed to climb into their mother's pouch.

(Please note the underlined keywords that are crucial in the line of reasoning in the argument and that represent the core point of the argument).

So here we go. The important words here are so that.
The argument's line of reasoning is that, as development of only forelimbs in kangaroos is for the purpose of Joey's climbing in its mother's pouch, the development of only forelimbs in ancient marsupial lions also implies that they needed to climb into their mother's pouch.
One of the assumptions made here is that the one definite purpose that only the forelimbs would develop in ancient marsupial lions would be to climb into their mother's pouch.
We will look for a choice that ties together premises and conclusion.

[A] All animals that are born after a short gestation period are born with some parts of their bodies underdeveloped. - The choice is too broad. In fact, this choice has no links to the conclusion. the author does not assume that anything about all animals born after a short gestation period. In fact, the author does not mention the gestation period of ancient marsupial lions being short either! The conclusion would hold even if this choice were not true. Hence, this is not an assumption.

[B] Well developed forelimbs would have been more advantageous to ancient marsupial lions than well developed hind limbs would have been. - The author does not assume this. Even if well developed forelimbs were not more advantageous than well developed hindlimbs, the conclusion would hold true. This choice is too broad in that term advantageous does not suggest that the advantage was specifically for the purpose to climbing into the mother's pouch. Also, this choice has not link to the conclusion.

[C] If the newborn marsupial lion did not climb into its mother’s pouch, then paleontologists would be able to find evidence of this fact.
This seems close but not accurate. This choice does address the conclusion. However, it does not bridge the gap between the premises and the conclusion. Paleontologists are beyond the scope of the argument. This does not address the line of reasoning, though it addresses the conclusion. That paleontologists would be able to find the evidence if the assumption were not true, is not an assumption here.
This is a trap choice - close but wrong. Strategically placed before the correct one :)

[D] Newborn marsupial lions that crawled into their mothers’ pouches could not have done so had they not had only their forelimbs developed at birth. - Beware! This is a trap choice. This suggests that the the only means of climbing into mother's pouch is having only well developed forelimbs. HOWEVER, the assumption is actually that atlease one definite purpose of well developed forelimbs is climbing into the pouch.
Further, it is possible that the lions or Joey had other means to climb into the pouches, in addition to well developed forelimbs. The argument foes not deal with them. It only says that the purpose of forelimbs was climbing in the pouch.

[E] Newborn marsupial lions would not have had only their forelimbs developed if this development were of no use to the marsupial lions - This choice is broad but decent. Use here does not indicate climbing into the mother's pouch. Negating this would mean that newborn lions may have had only their forelimbs developed even if this development were of not use to them. This is it! This version destroys the argument that the puspose of development of forelimbs was to climb into the pouch, as negating the choice indicates the possibility that the development may have been purposeleess.
This choice might be too broad or inadequate in that the term use is too broad. However, it is one of the subtle assumptions made in drawing the conclusion!
avatar
illrockgmat
avatar
Joined: 26 May 2011
Last visit: 14 May 2013
Posts: 12
Own Kudos:
3
Posts: 12
Kudos: 3
Knewton Challenge: Win Knewton Shirt and GMAT Club Tests 03 Sep 2011, 11:08
Kudos
Add Kudos
Bookmarks
Bookmark this Post
A newborn kangaroo, or joey, is born after a short gestation period of only 39 days. At this stage, the joey’s hind limbs are not well developed, but its forelimbs are well developed, so that it can can climb from the cloaca into its mother’s pouch for further development. The recent discovery that ancient marsupial lions were also born with only their forelimbs developed supports the hypothesis that newborn marsupial lions must also have needed to climb into their mothers’ pouches.

The argument in this passage relies on which of the following assumptions?

[A] All animals that are born after a short gestation period are born with some parts of their bodies underdeveloped.
[B] Well developed forelimbs would have been more advantageous to ancient marsupial lions than well developed hind limbs would have been.
[C] If the newborn marsupial lion did not climb into its mother’s pouch, then paleontologists would be able to find evidence of this fact.
[D] Newborn marsupial lions that crawled into their mothers’ pouches could not have done so had they not had only their forelimbs developed at birth.
[E] Newborn marsupial lions would not have had only their forelimbs developed if this development were of no use to the marsupial lions.

According to me the answer is "E"

Reason for my ans: The assumption in Option E is simply one which eliminates any/all other alternate causes for the given conclusion which is:" newborn marsupial lions must also have needed(forelimbs) to climb into their mothers’ pouches."
If we simply negate the assumption in E the conclusion collapses. Hence E
   1   2   3   
Moderator:
MBAACCOUNT2025
General GMAT Forum Moderator
444 posts