Most bio-historians believe that a particular disease emerged in

Question

Most bio-historians believe that a particular disease emerged in Central Africa less than 15,000 years ago and spread northward into Europe and Asia. But the recent discovery in Northern Europe of human remains conclusively proven to have died of the disease 28,000 years ago has led some scientists to postulate that the disease emerged in Europe and spread southward.

Which of the following, if found, would provide relevant evidence against the conjecture described above?

(A) Human remains in Southern Egypt show evidence of the disease, and are dated to 12,000 years ago.

(B) Some diseased African remains predate any found in Europe.

(C) The likelihood of an African of 15,000 years ago dying of the disease was greater than that of a European of 28,000 years ago.

(D) The 28,000-year-old infected remains in Europe were found among other remains dated between 4,000 and 30,000 years old.

(E) A European ice age about 20,000 years ago killed off the pathogen that causes the disease.

mikemcgarry · Accepted Answer

I'm happy to help with this. :-)

We want evidence against the claim that the disease spread from Europe to Africa --- this could be evidence for the claim that the disease spread from Africa to Europe. (A) Human remains in Southern Egypt show evidence of the disease, and are dated to 12,000 years ago . This is much later than other dates described, so it could have come from either direction. No good. (B) Some diseased African remains predate any found in Europe. Interesting. This would suggest the disease was in Africa before it was in Europe. This is quite promising. (C) The likelihood of an African of 15,000 years ago dying of the disease was greater than that of a European of 28,000 years ago . Well, this speaks more to the health conditions of people in those different times and places, and does not make clear where the disease existed first. No good. (D) The 28,000-year-old infected remains in Europe were found among other remains dated between 4,000 and 30,000 years old. Hmmm. We know how old the remains are. If other objects of different ages are tossed into the mix, that doesn't change how old the remains are of the guy who died from this diseases. This is no good. (E) A European ice age about 20,000 years ago killed off the pathogen that causes the disease . This is tempting --- it might make one leap to the conclusion: OK, the disease ended in Europe, so Africa couldn't have gotten it from Europe. BUT, this date, 20,000 years ago, is 8,000 years after the first documented case in Europe. Eight thousand years is a very long time! Surely it's possible that, in that 8,000 year period, some infected European went south and infected some Africans. We don't know for sure, but this one doesn't clearly call the "Europe to Africa" theory into question. It's no good. The only possibility is (B) . It supports the "Africa to Europe" theory, and thus provides evidence against the "Europe to Africa" theory. Does all this make sense? Mike :-)

ankurgupta03 · Answer

Option B clearly states that Some diseased African remains predate any found in Europe, hence the correct answer

Archit143 · Answer

Option B clearly weakens the fact that the disease evolved in Europe and travelled southwards.. It says there are some unevaluated human remains.

Consider kudos if my post helps!!!

Archit

Bluelagoon · Answer

Well you erased D very easily. I thought it might call into question the validity of the 28000 year old fossil. Don't you think so ? B clearly points out that fossils in africa predates any finding in europe. This is clear cut answer though but does GMAT through such options at us ? i mean so direct. First it gives all these facts and than say by the way the facts given are irrelevant. ?

BeckyRobinsonTPR · Answer

We are looking for evidence to weaken the conclusion that the disease started in Europe. The argument itself uses a timeline as it's premise. It implies that earlier remains with evidence of the disease show the emergence of the disease. Therefore in order to provide evidence against this one would have to find evidence of the disease in earlier remains outside of Europe.

A) 12,000 years ago is later so this doesn't help our timeline
B) This is the answer because is shows earlier remains in Africa than in Europe so the disease could not have started in Europe.
C) likelihood of dying is not at issue in this argument so it cannot weaken the conclusion.
D) if we know the exact date of the remains knowing what else was found with them doesn't matter.
E) knowing when the disease ceased being virrulent doesn't help because we want to find earlier infected remains.

Thus B is the only answer that attacks the author's line of reasoning.

jlgdr · Answer

Ya, but still B says some diseased African remains bla, bla bla How do we know we are talking about the same particular disease here if nothing is mentioned? I just don't buy this Anyways, answer is B Hope it helps Cheers! J

Udai · Answer

EXACTLY it might be some other disease not neccessarily the one stated in the passage... all of the answer choices remain awkward E looks best out of them

Mascarfi · Answer

Agree with the two comments above, B simply does not say that it died because of that specific disease.

D looks good to me (although not perfect), since they were found with remains of 4k and 30k years old, they might not have died in that area.

This is not a good question.

mikemcgarry · Answer

Dear Mascarfi , I agree that the question has a number of flaws. The prompt question says: " Which of the following, if found, would provide relevant evidence against the conjecture described above? " Technically, we can't be sure whether the " conjecture " means what the first group of scientist " believed " or what the second group " postulated ." Also, as you point out, the OA, (B), talks about " some diseased African remains ," and we are to assume that this means folks who died of the same disease discussed in the prompt. This is sloppy--- the GMAT would never do that. I will say that the problem with (D) really has to do with the nature of how remains are dated in archaeology and paleontology. You see, scientist can date any former living thing using something called carbon-dating , which compares the amount of radioactive carbon-14 in the former living thing to the amount in Earth's atmosphere. Even if there are a bunch of items of vastly different ages in some kind of site, scientists are able to carbon-date each item separately. Thus, even if there are other items that are older or younger along with the " infected remains ," this creates absolutely no ambiguity about the precise age of these infected remains. You don't have to know the scientific details of carbon-dating, but you should appreciate that you can use this technique to get the precise date of each item separately. BTW, notice that even here, the answer choice says the remains are " infected ," but again, the question doesn't specify that the infection is the same disease. The language is very sloppy in this question. You don't need to be an expert in anything, but for GMAT CR, you need to have the gist of a number of real-world situations. See this blog article: https://magoosh.com/gmat/2014/gmat-criti ... knowledge/ Does all this make sense? Mike :-)

Mascarfi · Answer

Hi Mike,

Thanks for the answer. And nice article by the way...

Just to clarify, I am aware that scientists are able to date any former living thing, what I said is that the remains were found in the same place but they might have been moved there from its original location, this would explain this remains from different ages at the exact same place...

Imagine that 5k years from now someone digs out what used to be a museum today, they will find remains of different ages at the same place because these remains were brought there from many different places. I agree that we need to make many assumptions to get to the answer D and I confess that because the question was 95%, I thought that B was just too obvious.

mikemcgarry · Answer

Dear  Mascarfi ,
Ah, I see. If the debate were between origins of two closely located regions, say Paris and Orly, then it is conceivable that someone from one region might have wandered to the other and died, or that the remains of someone were moved over a few miles for some reason. The debate in this question is between the European vs. Central African origin of a disease. Getting someone's remains from one continent to another would be more than big rigmarole, and so far as I know, there is no evidence that anything like this took place in the prehistoric world. In our modern world of shipping and airlines, it is much easier to get all kinds of items from one corner of the globe to another, but it was not always that way. 
Mike

mvictor · Answer

i picked D, and mostly because the disease, or at least bacteria of the disease could jump from one to another without any problem, thus the 28k year old remains were not actually of an infected person.

mikemcgarry · Answer

Dear mvictor , I'm happy to respond. :-)

My friend, in order to do well on GMAT CR, you don't need to be an expert on the particularly subject matter discussed in the question, but you do have to have a general sense of how the world works. Your supposition overlooks a set of very important facts from biology. A living body is very different from a dead body of the same kind of creature. In particular, the living body has an active immune system, which will go through all kinds of responses to a bacteria if one infects the body. The dead body will exhibit no immune response. In fact, the kind of bacteria that has interest in infecting a living body will want to do so precisely because of all the things that the bacteria can get from the living body: nutrients and warmth and so forth. The types of bacteria that would infect a dead & decomposing body would be of an entirely different category than those that would infect a living body. After a long time (a few years), a dead body, even a well-preserved one, is fully dehydrated, which essentially would make it impossible for any bacterial to infect it. It would be as impervious as a rock to any bacterial infection. What the scientist found was " human remains conclusively proven to have died of the disease ." In other words, they conclusively know that this human got the disease when living and subsequently died of it. Presumably, they see the evidence of the person's immune system and how it responded to the bacteria. Once again, whatever those responses were, none of them would have been present if the infection took place after the person was dead, especially dead for a long time. Part of this is that we have to take the premise information at face value. In particular, we have to assume that the scientists knew what they were doing and what they were concluding. If the scientists were sure that the person died of the disease, then we know that the person was infected while living. Part of this is that you don't have to be a medical expert, but you have to have to have the big gist picture of how things such as the immune system work, and how the biology of a living thing differs from the biology of a dead thing. This part of the real world background knowledge you will need to be successful on the GMAT CR. See this article: https://magoosh.com/gmat/2014/gmat-criti ... knowledge/ Does all this make sense? Mike :-)

mvictor · Answer

Thank you Mike for your effort and explanation. This does make sense.

To be honest, I narrowed down to B and D, but thought B is too obvious to be true, since CR questions do not throw such an exact answer directly at you. Thus, I thought it might be a trap or smth

Mahmud6 · Answer

If the disease emerged in Central Africa less than 15,000 years ago, how the predate African died in Europe 28000 years ago? Can not relate. Help please.

daboo343 · Answer

Here is the OE

Identify the Question Type:

The words "evidence against" identify this as a Weaken question.

Untangle the Stimulus:

The conjecture in question: recent evidence shows that a disease started in Europe at least 28,000 years ago and then spread south to Africa, which contradicts the standard view of the disease originating in Africa.

Predict the Answer:

Any information that indicates the disease may have originated in Africa will weaken the argument.

Evaluate the Answer Choices:

(B) is correct. It states that the earliest known diseased remains were found in Africa, not in Europe, and thus goes against the conjecture that the disease emerged in Europe and spread southward.

(A) does not affect the theory in any way – the discovery of 12,000-year-old evidence of the disease does not have any impact on the older evidence that already exists.

(C) discusses the likelihood of death from infection, which has no bearing on the conjecture about where the disease emerged.

(D) is irrelevant. The 28,000-year-old European remains are the same whether or not they are surrounded by other remains.

(E) is a strengthener. If the pathogen died out 20,000 years ago, there's a reason for the lack of 15,000-20,000-year-old diseased remains in Europe, which helps explain why scientists have mistakenly assumed that the disease started in Africa about 15,000 years ago.

TAKEAWAY: To weaken a claim, look for any information that indicates the claim may be incorrect.

arora1 · Answer

This is one of those tricky questions that have " some " in the correct answer choice. Recently, I have observed an increase in the number of such official questions too.

NikhilST · Answer

I happily eliminated B first. It was only later that I realised I had misread 'diseased' as 'deceased'

. This was a simple question, though!

Dbrunik · Answer

hey Mike, how can we know that in answer B, "diseased" is not just a general term here? i got confused because in the prompt it says "Particular disease"

given this language, in B, that Diseased was too general of a term. So what if some disease remains predate any in europe. There are a massive number of diseases. How can we know this?

Most bio-historians believe that a particular disease emerged in

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Most bio-historians believe that a particular disease emerged in

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