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 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.

Pls explain how you comprehend two negation in a sentence?

OA Post discussion..

Take some time to understand the argument first.

"A joey has a short gestation period but its forelimbs are well developed so that it can climb into its mother’s pouch for further development."

The argument is telling you that the reason the forelimbs of a joey are well developed is that it needs to climb into its mother's pouch.

"marsupial lions were also born with only their forelimbs developed so newborn marsupial lions must also have needed to climb into their mothers’ pouches."

It further states that marsupial lions were also born with only forelimbs developed. So they must have needed to climb into their mother's pouches too. The argument assumes here that forelimbs were developed for a reason and that reason was 'climbing into mother's pouch'. It assumes that if the lions did not have a need for the forelimbs to be developed, the forelimbs would not have been developed. Since the forelimbs were developed at birth, it was for a reason. Hence E is correct.

As for D, the argument is not assuming this.
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 argument says that developed forelimbs implies crawling into mother's pouch. It doesn't say that crawling into mothers' pouches implies developed forelimbs. Notice what has been found and what has been implied. It has been found that these lions had developed forelimbs. This implies that they crawled into pouches.

If we were given that it has been found that the lions crawled into their mothers' pouches and that this implies that their forelimbs must have been developed, then we could have said that the argument is assuming that without developed forelimbs, the lions could not have crawled into their mothers' pouches. Hence D is not correct.

It comes down to understanding conditional sentences.
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Karishma
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Sure. No point wasting too much time on one question. That said, during practice, ensure that you understand the logic used in every question and give as much time as required to do it.
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Karishma
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