#18 - Foster: Many species of extremely large North American

[Administrator]

Complete Question Explanation

Strengthen-CE. The correct answer choice is (E)

In this dialogue, Foster and Fisch take opposing stands regarding the cause of the extinction of many species of extremely large North American mammals. Foster attributes the extinction to humans:

• Human changes extinction

Fisch, on the other hand, believes the environment was to blame:

• Climate changes extinction

Answer choice (E): This is the correct answer choice. The question asks that we strengthen Fisch’s argument, so we should look for the answer choice that either provides further evidence that the climate was the culprit, or the choice that allows us to rule out other possible explanations. In this case, answer choice (E) gives us more evidence that climate changes were to blame for the discussed extinctions. If the large mammals were unable to migrate to milder environments, then there is more reason to believe that the climatic changes that took place would have had a more severe effect.

Answer choice (A) weakens the argument, by showing that the climate doesn’t always lead to extinction of such species. Answer choice (B) doesn’t strengthen Fisch’s argument at all—this choice doesn’t even reference the climate, which Fisch argues to be the primary cause. Answer choice (C) weakens Fisch’s argument and strengthens Foster’s, by providing evidence in favor of humans as the culprit. Answer choice (D) is of questionable relevance, but if it provides strength to either side, it helps Foster, since this choice provides some evidence that perhaps humans were hunting or killing the large mammals which eventually became extinct.

[avengingangel]

I correctly answered this question by choosing E. But, to confirm, can we say that E is a perfect example of a "Weak But Still Strengthens" answer choice?! After reading the question prompt then reading the stimulus, I prephrased/decided that I was looking for something that strengthened the likelihood that the extinction was a result of climate change & not migration—in other words, ideally I would see an example/add'l info in which you have EXTINCTION, but WITH a harsh climate change and WITHOUT a migration. However, when I blew past ABCD, thinking wow those are ugly answer choices, I got to E and was like, huh ?? "milder environments" ?? I wasn't even 100% sure that that was talking about climate (it could be that mammals had less predators, etc.) But remembered that correct weaken/strengthen only have to help/hurt the argument a LITTLE bit to be correct.

[mshaikh]

I have the same questions as the person above. I got this answer correct because all the other AC's were obviously wrong but is this an example of an answer choice that only slightly strengthens the argument?

[Francis O'Rourke]

It's hard to put my finger on how strongly this answer choice strengthens the argument, but I believe that it is stronger than you are giving it credit for.

Fisch claims that the rapid pace of the change is evidence that the climate change caused the extinction of these mammals. Answer choice (E) directly supports this idea by telling us that these mammals could not quickly move to milder - i.e. less harsh - environments. It does not matter that environment is a broader term than climate, since the idea of environment includes climate.

Choice (E) does include a phrase that is likely to have tricked a lot of test takers. Foster claimed that human migration was to blame for the extinctions of this era. Fisch disagrees with this and gives an alternate explanation, so we want something that directly or indirectly weakens Foster's explanation of human migration. Choice (E) does this, but uses the word migrate to refer to the extinct mammals. If you were to read this answer choice too quickly, you might be tempted to cross it off as soon as you see an answer that claims that some form of migration played a role in the extinctions. This is what makes answer (E) so tricky: even though it uses a specific word that Foster employed in her argument, this answer choice uses it in a way that supports Fisch's argument.

[mshaikh]

That makes sense! Thanks so much for the explanation! I think the word migration threw me off. I guess this is a good reminder to carefully read an answer choice before crossing it off.

[Mariam]

Hello- I was stuck between answer choices B and E because I though E supported the causal relationship and B eliminated an alternative cause. Can someone please further explain why B does not support Fisch's argument by eliminating the possibility that human migration was the cause, an alternative cause?

[KelseyWoods]

Hi Mariam!

I like that you're looking to eliminate alternate causes when strengthening causal arguments! In this case, however, answer choice (B) doesn't eliminate human migration as the cause of the extinction of many species of North American mammals. Answer choice (B) tells us that the mammals that survived migrated from Asia with the humans. So the North American mammals that became extinct were the ones that hadn't migrated with the humans and therefore had not actually encountered humans before. Thus, it could still be the human migration that resulted in the extinction of many species of North American mammals.

Hope this helps!

Best,
Kelsey

[Mariam]

Yes it does, Kelsy, thank you! I was thinking about mammals at large.