Q18 - Foster: Many species of

[patrice.antoine]

Strengthen question here and I understand why A, C and D are wrong choices:

A - Weakens Fisch' conclusion

C - Presents an alternative reason that resulted in extinction

D - Same as above.


Can anyone explain why B is wrong here?

[ohthatpatrick]

I would just add to (C) and (D) that they strengthen Foster's argument. They make it seem more like the arrival of humans is the reason for the many extinctions.

(B) is basically neutral to both arguments. Since (B) is discussing neither large mammals who went extinct nor harsh climates, it's not going to have any effect on Fisch's argument.

Does (B) help convince us that a shift to a harsher climate killed off large mammals in North America?

No, it doesn't really have anything to do with climate (or large mammals, specifically).

(E) on the other hand, addresses both.

Let me know if you thought there was a way to interpret (B) that would be relevant to Fisch's theory of "harsh climate killed the large mammals".

I think some people might feel like (B) goes against Foster's argument. If so, we might think, "Well, since Fisch is arguing with Foster, then maybe weakening Foster is just as good as strengthening Fisch."

But there are 2 problems with that thought:
1. (B) doesn't weaken Foster's argument.
2. Fisch's conclusion wasn't "Foster, you're wrong". If that WERE Fisch's conclusion, then weakening Foster WOULD be strengthening Fisch. But Fisch's argument is specifically that climatic change killed the large mammals.

Hope this helps. Let me know if you interpreted (B) in a way I didn't cover.

[patrice.antoine]

Could it also be true that (B) in no way suggest that "many species of extremely large NA mammals" where in fact part of the "most mammals" that survived?

If it were, then I can see how it weaken's Foster's argument, but we cannot assume that this is the case (ie the "many" were part of the "most").

I wish I can speedily think of such break downs during the 1:15 minutes we have to answer these! Thanks for taking the time to thoroughly explain and also provide additional reasons to why the other answer choices are wrong!

[griffin.811]

So I had this narrowed down to B and E. I do think B strengthens F's argument, just not as much as E, and here's why:

IMO, B strengthens because it seems to suggest that humans co-existed with SOME animals, extending the possibility that maybe it wasn't the humans that caused the extinction. After all, they allowed the other animals to live.

(I see the other side to this as well. Maybe they only killed off the larger animals [better tasting meat, warmer fur, etc...] because they were more valuable to them at the time)

E is the better answer because it addresses either directly or indirectly a few of the claims F makes.

1. Says the HUGE SIZE of the animals (mentioned in the passage) made it....

2. DIFFICULT to MIGRATE the GREAT DISTANCES to MILDER ENVIRONMENTS.

This shows that the animals would not have been able to escape the harsh climate, thus providing a (better) reason as to why the humans may not have been responsible for the extinctions.

**When down to two answer choices, and stuck, quickly compare the language of the answer choices to that of the passage and select the better fit. While this won't always yield the correct answer, it more often will IMO.

[WaltGrace1983]

So I had this narrowed down to B and E. I do think B strengthens F's argument, just not as much as E, and here's why:

IMO, B strengthens because it seems to suggest that humans co-existed with SOME animals, extending the possibility that maybe it wasn't the humans that caused the extinction. After all, they allowed the other animals to live.

(I see the other side to this as well. Maybe they only killed off the larger animals [better tasting meat, warmer fur, etc...] because they were more valuable to them at the time)

This, however, is not our task. We aren't trying to weaken Foster's claim - we are trying to strengthen Fisch's claim! Granted, most really good strengthening/weakening answers to these type of dialogical questions often do BOTH, which makes those correct answers even more awesome. However, simply weakening Foster's claim doesn't do anything for us unless it also strengthen's Fisch's claim! Simply weakening A when the goal is to strengthen B is not sufficient in itself. I do see where you are coming from with (B), but sometimes you just gotta think, "were we really supposed to read that deeply into it?" If it takes a lot of hard work to make an answer choice work, be skeptical.

One thing to remember is that only in rare cases is one strengthen answer just "better." Typically, there are four answer choices that simply don't strengthen and one that does. It has helped me to think about strengthen questions in this way. Looking for "better" can often lead to assumptions but looking for the "only" often gets your mind in a better place.

Another thing that has helped me when strengthening/weaken arguments is to just repeat the conclusion over and over in your head. REMEMBER THE TASK. "Strengthen X....Strengthen X...does this strengthen X?...No...Does this strengthen X? Yes..." That is literally the dialogue that happens sometimes when I am struggling with an answer.

Let's break this question down.

Foster:

Large mammals' extinction correlated with human migration to N.A.
→
Human migration caused extinction


Fisch:

Large mammals' extinction correlated with climate change
→
Climate change caused extinction


As you can see, these are two correlation/causation arguments. Both Foster and Fisch give us a correlation and say that, just because X and Y happened around the same time, one caused the other. The problem? Correlation does not equal causation and strengthener questions such as this one often hinge on this very distinction.

So we need to strengthen Fisch's claim. How do we do this? Well I think one thing that is important to note here is that we have to take Fisch's premises as true. That is, we know that there was a harsh climate change because this is said in Fisch's premises; we thus have no reason to doubt it. So why would harsh climate change cause extinctions? Well what if the animals didn't have the means to handle this climate change. It looks like we are talking about the ice age, right? Well what if the animals didn't have enough fur to keep them warm? What if these large mammals were cold-blooded and this kept them from living? The animals probably could migrate but what if they couldn't?! Let's go to the answer choices and remember our task.


(A) This weakens Fisch's argument! That's no good; we want to strengthen it! Why does it weaken? It shows that there was the purported cause (climate change) correlated with the absence of the purported effect. Fisch asserts, "Climate Change → Extinction." However, if (Climate Change → ~Extinction) then Fisch has got to be wrong in his assertion. Whenever we have a cause and effect argument from a correlation, having a cause correlated with an absence of the effect weakens the causal connection.

(B) This weakens Foster's conclusion but doesn't do much to Fisch's conclusion. Why does it weaken? Because It shows that mammals did survive even when they existed at the same time humans migrated. In a way, this also gives a cause (human migration) with the absence of the effect (~extinction). Granted, there still is some grey area - as mentioned - when we go from talking about "large North American mammals" to "mammals" in general.

(C) This just strengthens Foster's argument but doesn't speak to climate change, which is the main point we are getting after. It gives us the same cause (human migration) with the same effect (extinction) in Foster's argument.

(D) This doesn't even mention the large mammals or climate change! Out of scope.

(E) This strengthens! If these mammals couldn't move well, and climates became harsher, then it makes sense that this inescapable harsh climate would have killed the mammals. Plus, the others are clearly wrong!

[mkd000]

If we strengthen Foster's argument (ie, C and D), does this necessarily weaken Fisch's argument? Any assistance with answering this question would be greatly appreciated.

Thanks!

[ohthatpatrick]

If two people were fighting over a binary idea (X is / X isn't), then strengthening one is the same as weakening the other.

Would we consider THIS debate a binary one?

Kind of --- Foster says humans were responsible, Fisch says climate was.

Are those actually mutually exclusive options? No. It's possible human migration AND climate change both mattered.

But the way Fisch words his conclusion makes it seem like "those extinctions were [exclusively] caused by harsher climate."

So in that sense, making it seem like human migration had some responsibility DOES weaken Fisch's conclusion.

But, again, we're not really saying that (C) and (D) do much to strengthen Foster. It's enough to glance at them and hear to yourself, "Meh, this sounds like Foster's hypothesis, not Fisch's."

[Emmeline Ndongue]

(B) This weakens Foster's conclusion but doesn't do much to Fisch's conclusion. Why does it weaken? Because It shows that mammals did survive even when they existed at the same time humans migrated. In a way, this also gives a cause (human migration) with the absence of the effect (~extinction). Granted, there still is some grey area - as mentioned - when we go from talking about "large North American mammals" to "mammals" in general.

Just want to add why this doesn't weaken. as patrice.antoine. pointed out: the "many large mammals" might not overlaps with "most survived mammals". Why? many means "one or more", most means ">50%". The "many" could well just be what the "most" lacks. If you're unsure of whether it overlaps, you're unsure of the "cause present" & "effect absense" relationship, since it could be talking about 2 completely different subject matters.