marsupial lions

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marsupial lions

by kaulnikhil » Tue Jun 01, 2010 9:30 am
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 forelegs developed if this development were of no use to the marsupial lions

Pl provide reasons for selecting between D and E.

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by 4GMAT_Mumbai » Tue Jun 01, 2010 10:38 am
Hi,

Pretty interesting and tough one ... Thanks kaulnikhil !

D: This seems to suggest they could not have done the crawling if any other part had developed well (apart from forelimbs). This might have been correct if the statement said '... had they not had AT LEAST their ...'

E: IMO, this sounds more like the answer. The researcher is searching for facts to support the highlighted hypothesis. The fact that the newborns had ONLY their forelimbs developed well seems to add credence to the hypothesis that it had to drag itself.

Hope this helps. Thanks.

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by jube » Tue Jun 01, 2010 11:37 am
I selected E because nowhere in the passage does it state that newborn marsupial lions actually crawl into the lion's pouch - if anything this is an assumption implied by the last sentence.

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by kstv » Wed Jun 02, 2010 12:14 am
The other forums have OA as E.
This is a tough one for me partly cos of the wording. Too much of perfect tense in the options.

Newborh Kangaroos use developed forelimbs to climb to their mother's pouch.
Marsupial lions had developed forelimbs.
Conclusion is that they needed to climb to their mothers pouch.
Between the premise and conclusion the missing link should be the assumption.

I strongly feel option D is the link.

Option E - The develepment of forelimbs was useful for the lions. If it was not useful the forelimbs will not be development. Is this not - A implies B, so opposite of B has to imply opposite of A. Is this logical ?

Incidentally

Because a newborn marsupial must climb up to its mother's nipples, the otherwise minimally developed newborn has front limbs that are much better developed than the rest of its body.
https://en.wikipedia.org/wiki/Marsupial

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by saurabhmahajan » Wed Jun 02, 2010 1:53 am
IMO:D
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.
states that the same was the assumption made for marsupial lions.

OA plz.

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by kaulnikhil » Wed Jun 02, 2010 1:56 am
saurabhmahajan wrote:IMO:D
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.
states that the same was the assumption made for marsupial lions.

OA plz.
OA E

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by FightWithGMAT » Fri Jun 04, 2010 6:34 am
kaulnikhil wrote: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 forelegs developed if this development were of no use to the marsupial lions

Pl provide reasons for selecting between D and E.

Wonderful question to puzzle most of the aspirants. After analyzing this for minutes, I could get the extract of this question.
E is correct here:

Need to climb is the only reason of having forelimbs developed......there is no other reason (MUST word in argument suggests so)......what if the development of forelimbs in newborn lions took place without any reason.........would weaken the reasoning.

Now analyze D, which says:

The newborn lions could have not climbed into the pouch if they had not had forelimbs developed.

This would be the answer if the last few lines of the argument were:

The recent discovery that ancient marsupial lions had newborn ones who used to climb into the pouch supports the hypothesis that newborn marsupial lions must also have had heir forelimbs developed

Negate D
The newborn lions could have climbed into the pouch even if they had not had forelimbs developed.
or

Though newborn lions had forelimbs developed, they could not climbed into the pouch.

both the negations would weaken the reasoning....

So E is only answer.

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by kaulnikhil » Sat Jun 05, 2010 2:27 am
FightWithGMAT wrote:
kaulnikhil wrote: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 forelegs developed if this development were of no use to the marsupial lions

Pl provide reasons for selecting between D and E.

Wonderful question to puzzle most of the aspirants. After analyzing this for minutes, I could get the extract of this question.
E is correct here:

Need to climb is the only reason of having forelimbs developed......there is no other reason (MUST word in argument suggests so)......what if the development of forelimbs in newborn lions took place without any reason.........would weaken the reasoning.

Now analyze D, which says:

The newborn lions could have not climbed into the pouch if they had not had forelimbs developed.

This would be the answer if the last few lines of the argument were:

The recent discovery that ancient marsupial lions had newborn ones who used to climb into the pouch supports the hypothesis that newborn marsupial lions must also have had heir forelimbs developed

Negate D
The newborn lions could have climbed into the pouch even if they had not had forelimbs developed.
or

Though newborn lions had forelimbs developed, they could not climbed into the pouch.

both the negations would weaken the reasoning....

So E is only answer.
Oa E

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by nikhilkatira » Sat Jun 05, 2010 3:13 am
Good question Nikhil.
Best,
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by frank1 » Sat Nov 27, 2010 4:56 am
nikhilkatira wrote:Good question Nikhil.
To be frank i dont think so.

I was able to come down to D and E.(i felt which means i am not doing bad though i was not able to choose 1)

I think source of this question is knewton...
They have not officially released explanation and answer in their website.They have called to their office to know answer.

I find wording of E almost like maze(you need almost 1.5 minutes almost to understand what does it actually means) plus I think D and E can both qualify as answer.
People will be able to dig reason for both i guess.More over its assumption question which complicates the things even more.

thanks
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by divineacclivity » Sun Aug 24, 2014 6:11 pm
Experts,

Please help here:

Still confused between D and E and D sounds only better of the two to me for the reason below:

E would've sounded better if it was slightly different:

[E] Newborn marsupial lions would not have had only their forelimbs developed if this development were *not for climbing to the lion's pouch* instead of "of no use to the marsupial lions."
or had this option been like the one below:
[E] Development of the forelimbs is NOT/NEVER for any other purpose.
I rejected option E with an understanding that it is too extreme to say "of no use to M. lions". They could've had developed forelimbs for some other purpose. So, the person arguing must think that "development of forelimbs" is NOT for any OTHER purpose i.e. is for the SOLE purpose of climbing to the pouch.

(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.

D is also a weak statement for an assumption since it says "they couldn't have crawled to the pouches if they didn't have developed forelimbs" -> this doesn't necessarily mean that they did use their forelimbs for climbing/crawling to pouches i.e. developed forelimbs might be a necessary criteria but not a sufficient one.

So, between E & D, I picked D since E was too extreme :(
Please help me here. Thanks in advance.

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by kutlee » Wed Apr 08, 2015 10:41 pm
Good question.
The argument already states that - "discovery that ancient marsupial lions were also born with only their forelimbs developed ".
So there is no question that only forelimbs were developed.
So there should be some use for those limbs. Then Scientists assumed that these limbs are used for climbing into the pouch. So E is the answer.
D is a slight variation of E. D is actually kind of restating the argument itself. Argument states that limbs are used to climb. Option D states that the lions would not have done so if the limbs had not developed. So D is kind of reverse of what argument already states.
This is what i think.
(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 forelegs developed if this development were of no use to the marsupial lions