Some anthropologists argue that the human species..

Question

Some anthropologists argue that the human species could not have survived prehistoric times if the species had not evolved the ability to cope with diverse natural environments. However, there is considerable evidence that Australopithecus afarensis, a prehistoric species related to early humans, also thrived in a diverse array of environments, but became extinct. Hence, the anthropologists’ claim is false.

The reasoning in the argument is most vulnerable to criticism on the grounds that the argument

(A) confuses a condition’s being required for a given result to occur in one case with the condition’s being sufficient for such a result to occur in a similar case

(B) takes for granted that if one species had a characteristic that happened to enable it to survive certain conditions, at least one related extinct species must have had the same characteristic

(C) generalizes, from the fact that one species with a certain characteristic survived certain conditions, that all related species with the same characteristic must have survived exactly the same conditions

(D) fails to consider the possibility that Australopithecus afarensis had one or more characteristics that lessened its chances of surviving prehistoric times

(E) fails to consider the possibility that, even if a condition caused a result to occur in one case, it was not necessary to cause the result to occur in a similar case

Edvento · Accepted Answer

The correct answer here is A.

Counter Premise: Some anthropologists argue that the human species could not have survived prehistoric times if the species had not evolved the ability to cope with diverse natural environments.

Premise: There is considerable evidence that Australopithecus afarensis, a prehistoric species related to early humans, also thrived in a diverse array of environments, but became extinct.

Conclusion: The anthropologists’ claim is false.

(A) confuses a condition’s being required for a given result to occur in one case with the condition’s being sufficient for such a result to occur in a similar case

"a condition’s being required for a given result to occur in one case"

Condition:ability to cope with diverse natural environments
Result: Survival
Case: Humans

Similar case: Australopithecus afarensis

So, here the choice says that the argument treats the condition to be  sufficient . That might not be the case.

(B) takes for granted that if one species had a characteristic that happened to enable it to survive certain conditions, at least one related
extinct species must have had the same characteristic

This makes no sense. The choice itself is contradictory. It is talking about the 'survival' of least one 'extinct' species.

(C) generalizes, from the fact that one species with a certain characteristic survived certain conditions, that all related species with the
same characteristic must have survived exactly the same conditions

This is untrue. The argument is not generalizing. It is holding up a specific case to disprove a claim.

(D) fails to consider the possibility that Australopithecus afarensis had one or more characteristics that lessened its chances of surviving prehistoric times

We don't have information to comment on characteristics that would 'lessen' chances of survival.

(E) fails to consider the possibility that, even if a condition caused a result to occur in one case, it was not necessary to cause the result to
occur in a similar case

The word 'sufficient' in place of necessary would have made it a better contender.

Regards,

Shouvik.

TGC · Answer

(A) confuses a condition’s being required for a
given result to occur in one case with the
condition’s being sufficient for such a result to
occur in a similar case

Can be correct, as a condition which had a result in one case is deemed to be sufficient in other case.

(B) takes for granted that if one species had a
characteristic that happened to enable it to
survive certain conditions, at least one related
extinct species must have had the same
characteristic

out of scope

(C) generalizes, from the fact that one species with
a certain characteristic survived certain
conditions, that all related species with the
same characteristic must have survived exactly
the same conditions
out of scope

(D) fails to consider the possibility that
Australopithecus afarensis had one or more
characteristics that lessened its chances of
surviving prehistoric times

correct , had AA had one more characteristic => less survival => weak argument

(E) fails to consider the possibility that, even if a
condition caused a result to occur in one case,
it was not necessary to cause the result to
occur in a similar case

Close but not accurate enough to meet already fighting options (A) and (D).

Plz post the OA , (A) or (D). or some other option

My take (D).

vomhorizon · Answer

It is definitely the OA..
The stimulus has the following key points:

Some anthropologists argue :

Some evidence also suggests :

Based on the last evidence, the author concludes :

So the author tries to logically conclude that because A. Afarensis, had the ability to adapt and thrive in diverse environments BUT COULD NOT SURVIVE pre historic times (and thus became extinct) the anthropologists are wrong.

The anthropological are trying to claim that the HUMANS could not have survived had they not possessed the ability to adapt. The anthropologists stop at that, and do not in any way STATE that the HUMANS would have SURVIVED had they had the ability to adapt ... Therefore the ability to adapt is considered by them as essential to surviving in pre historic times, however they do not claim that any species that has that ability is guaranteed of surviving those times ....

(A) confuses a condition’s being required for a
given result to occur in one case with the
condition’s being sufficient for such a result to
occur in a similar case

Questions that involve logical chinks or flaws are easy to predict (predict the answer ) .. and (A) is the right answer as explained ...

This is clearly out of scope .. He is attacking the anthropologists based on their reasoning ( he is trying to draw an inference that is not correct), therefore the correct answer choice must reflect that....

Hope it helps..

ChrisLele · Answer

The error in logic here is that the paragraph assumes that satisfying a condition (ability to live in diverse environments) automatically confers a result (survival). In other words, just because humans could live in a prehistoric environment and survive does not apply to every species. Therefore the paragraph comes to a mistaken conclusion: because the ability to live in diverse environments did not prevent the Austral. Afar. from going extinct, this ability cannot account for the success of the human species.

Thus what works in one case doesn't apply to all cases is, I hope, an easy to understand paraphrase of the answer (A)

.

TGC · Answer

Hi Chris,

Can You plz explain what is wrong with option (D). as in many of the questions we would have opted for option (D). also .
Plz pour in.

Rgds,
Saurabh

chesstitans · Answer

" there is a term shift between human species and this prehistoric related species, which (B) and (C) try to play on. In another question with different answer choices, this could very well be where the argument is most vulnerable to criticism. But in this question, be careful about trying to impose that term shift on the existing wrong answer choices to make them right--(B) is actually saying something can be boiled down to, "If humans had the ability to adapt and that's how they survived, at least one related extinct species must have had the same ability to adapt, too."

The argument already tells us that there is at least one prehistoric, extinct species had the same ability to adapt as humans--so the second, necessary condition in (B) is met. If anything, perhaps (B) strengthens the argument.

You're exactly right when you say (A) identifies the fundamental reasoning flaw, but without dealing with the term shift in the argument, and that's okay--it's still the fundamental reasoning flaw. Dan's analogy could be re-written with apes, like you suggested, but everyone knows apes in California make terrible friends."

the above is the confirm from manhattan on https://www.manhattanprep.com/lsat/foru ... -t290.html

chesstitans · Answer

"most vulnerable to criticism on the grounds that" can be either a logic question or a weaken question. My advice is if ones spot such phrase, glance at options to see whether it is logic or classical weaken question. Even if it is a logic question, ones should keep in mind that the question also includes a part of weaken question.

Madhavi1990 · Answer

I thought of first understanding the cause-effect format of the argument:

Some anthropologists argue that the human species could not have survived prehistoric times if the species had not evolved the ability to cope with diverse natural environments. However, there is considerable evidence that Australopithecus afarensis, a prehistoric species related to early humans, also thrived in a diverse array of environments, but became extinct. Hence, the anthropologists’ claim is false.

Anthropologist says: Human species + ability to survive in diverse env --> survival
Counter: AA species 'related to humans' + same ability --> extinction: WHY? thus Anthro. has made a false conclusion
Reexamine: ability necessarily doesn't mean the same outcome; if it did there could be other factors too

The reasoning in the argument is most vulnerable to
criticism on the grounds that the argument - we now need to find the closest method of reasoning that created this flawed conclusion

(A) confuses a condition’s being required for a
given result to occur in one case with the
condition’s being sufficient for such a result to
occur in a similar case - Echoes above : ability to survive doesn't mean outcome of survival

(B) takes for granted that if one species had a
characteristic that happened to enable it to
survive certain conditions, at least one related
extinct species must have had the same
characteristic Already stated - AA species had a common ability with humans

(C) generalizes, from the fact that one species with
a certain characteristic survived certain
conditions, that all related species with the
same characteristic must have survived exactly
the same conditions we don't know the 'all related species'

(D) fails to consider the possibility that
Australopithecus afarensis had one or more
characteristics that lessened its chances of
surviving prehistoric times we aren't discussing the differences between AA and humans - if that was the case this would true.
But since its about having a similar premise (ability) there were two different outcomes --> why was that? This is actually contradicting: '1 or more charac.s that lessened survival'; whereas argument says it shares the ability to survive with humans

(E) fails to consider the possibility that, even if a
condition caused a result to occur in one case,
it was not necessary to cause the result to
occur in a similar case similar case would mean humans here - not the AA species. AA species are not similar to humans; as we don't know anything except this shared ability they possessed

Really good question

chesstitans · Answer

fortunately, this is not a gmat-type question, and so the question can be practiced, but it is unlikely to appear in gmat.

chesstitans · Answer

hello, I want to ask you that LSAT or GRE-type questions will appear in GMAT?

GMATNinja · Answer

There's a ton of overlap between LSAT, GRE, and GMAT verbal questions, and most official LSAT and GRE verbal questions will be really good practice for the GMAT, too. All three tests are trying to test you on the same core skills: the precision of your reading and logic. I'm a big fan of LSAT materials in particular, and there's a long-winded rant about them here: https://gmatclub.com/forum/experts-topi ... 39365.html. There are some cosmetic differences, though. In particular, the question type in this thread doesn't show up on the GMAT all that often. So you're right, chesstitans : this particular question is probably good practice, but you don't need to spend too much time on this question type unless you really want to. I hope this helps!

Nightmare007 · Answer

Hi  GMATNinja ,  abhimahna , 
 I am confused between choices A and E. 
 Are we eliminating E because of the wording "A CONDITION" ? Both sound the same to me. Can you please explain me the difference.

Thanks in advance.

abhimahna · Answer

Hey  Nightmare007  ,

Looks like you didn't understand the argument properly.

The argument said to survive you MUST have ability to cope with diverse natural environments. This is similar to If P, then Q structure.

If P(survive) , then Q(have ability to cope with diverse natural environments).

Now, the only inference that can be drawn out of this is "~Q --> ~P". Meaning -> No ability to cope with diverse natural environments implies not survive.

Now, the author talked about some species and said it had the ability but it still didn't survive.

Please note that We already know that we have only inference for our condition. So, if I say Q --> P, this may or may not hold true.

This is what happened in case of specific species. Hence, this doesn't mean it will hold for every species.

Or in other terms, I am saying something being required doesn't mean it is sufficient.

Now, let's talk about option E. It says "even if a condition caused a result to occur in one case". We need to limit our scope to P and Q only. Option E is introducing a factor Z and is saying Z might not happen to all the species.

I don't care what actually happened to "Australopithecus ". All I know is If P, then Q cannot be broken!

Hence, option E is incorrect.

Does that make sense?

Nightmare007 · Answer

Yeah now it does. I forgot to look into the conditionals. It was an easy to spot but i failed to do so. 
Thank you.

user9123 · Answer

Hi all,

After reading all the responses, I was still confused about A vs E. I had to take awhile to think this through but I think this is my understanding below:

In the statement: " Some anthropologists argue that the human species could not have survived prehistoric times if the species had not evolved the ability to cope with diverse natural environments " - It's saying that human species would not have survived  without   the ability to cope. It's not saying that the ability to cope caused human species to survive. It could have been ability to cope + bigger brains + 2 legs caused survival aka it was not only the ability to cope that caused survival, but we don't know that and this statement doesn't say that. All that it says is that in order for human species to have survived, it needed the ability to cope.

If we understand that then we can see why E does not work.

E says: "fails to consider the possibility that, even if a condition caused a result to occur in one case, it was not necessary to cause the result to occur in a similar case"

Here it is saying, even if a condition (ability to cope)  caused  a result (humans survive) to occur... The anthropologist are not saying this, they're not saying that the ability to cope CAUSED humans to survive. They're saying in order for humans to survive they need the ability to cope. So essentially

Answer E says: A => B (ability to cope cause human to survive)
Answer A says: B needs A (humans to survive need ability to cope)

Hopefully this above diagram highlights the difference. Because E is a reasoning that is not expressed by the argument, it's not the best solution. A directly iterates a part of the argument and refutes it so A helps highlight the vulnerability.

IN2MBB2PE · Answer

Best Explanation to Hands down and also clears some of the confusion in concepts:

https://www.youtube.com/watch?v=Ih2XnTcB3I8

Oppenheimer1945 · Answer

KarishmaB , help with option D? Why can't it be correct?

VerbalBot · Answer

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Some anthropologists argue that the human species..

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Some anthropologists argue that the human species..

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