#9 - Archaeologists are currently analyzing plant remains

[Administrator]

Complete Question Explanation

Must Be True­—SN. The correct answer choice is (B)

The stimulus outlines two hypothetical scenarios about how the prehistoric inhabitants of some archaeological site used the plants that lived on that site. The author speculates that if the plants were cultivated, then the people who occupied the site discovered agriculture before anyone else. But if the plants were wild, then the site’s occupants ate a wider variety of wild plants than did anyone else at the time. The conditional relationships in the second and third sentences, respectively, can be diagrammed as follows:

• Cultivated Discovered agriculture before anyone else
  
  Cultivated Ate a wider variety of wild plants than anyone else

The question stem asks us to determine what is most strongly supported by the information contained in the stimulus. As you note, the two sufficient conditions are logical opposites of each other: the plants that lived on that site must have been either cultivated or uncultivated. Consequently, at least one of the two necessary conditions must also occur: either the occupants discovered agriculture before anyone else, or else they ate a wider variety of wild plants than anyone else. This prephrase is key to identifying the correct answer choice (B).

An alternative approach (one that you took) would be to combine the two conditional relationships in the stimulus, by using the contrapositive of either relationship. Thus:

• Discovered agriculture before anyone else Ate a wider variety of wild plants than anyone else
  
  and also:
  
  Ate a wider variety of wild plants than anyone else Discovered agriculture before anyone else

In other words, either the people who lived on the site discovered agriculture before anyone else, or else they ate a wider variety of wild plants than anyone else.

Answer choice (A): This answer choice is incorrect, because there is no evidence that the archaeologists will be able to determine whether the plants were wild or cultivated. It is exceptionally difficult to justify this level of certainty.

Answer choice (B): This is the correct answer choice. If the plants were cultivated and people who occupied the site discovered agriculture before anyone else, then it is reasonable to conclude that no one else used these particular plants in the same way as the site’s inhabitants did. Alternatively, if the plants were wild and the people who occupied the site ate a wider variety of plants than anyone else, then they ate at least some plants that no one else did (at that time). Either way, whether the plants were wild or cultivated, we can conclude that the people who occupied the site used some plants in ways that no other people did at that time.

Answer choice (C): We cannot speculate what types of plants were found at the site if the people who occupied it had reached a more advanced stage in the use of wild plants than anyone else at the time. Indeed, the only way to reach the conclusion proposed here (i.e. that the plants were uncultivated), would be to use the contrapositive of the first conditional relationship. In other words, we would need to know that someone else discovered agriculture before the people who occupied the site did:

• Discovered agriculture before anyone else Cultivated

Clearly, this answer choice does not allow us to determine who discovered agriculture first. Consequently, we cannot prove that the plants found at the site were uncultivated.

Answer choice (D): This answer choice contains a Mistaken Reversal of the first conditional relationship:

• Cultivated Discovered agriculture before anyone else
  
  MR: Discovered agriculture before anyone else Cultivated

Answer choice (E): The stimulus provides no information to help us determine which one of the two necessary conditions is more likely to be true. This answer choice attempts to infer a comparative claim from an absolute one.

[sarae]

Why is B correct? How can we be sure that people who occupied the site used some plants in ways that no other people did at that time (unless we are sure that the plants were uncultivated)

[Steve Stein]

Hi sarae,

If the plants were cultivated by the occupants before anyone else, or if the occupants ate at least some plants that no one else did at the time, either way (whether the plants were wild or cultivated), the people who occupied the site used some plants like no one else at that time.

Please let me know whether this is clear--thanks!

~Steve

[sarae]

ok so just by them discovering it we can conclude that they used it in some way. Thanks!

[UnimelbLsat]

I used the condition reasoning method outlined above.
However, I ruled B out, because initially B sounds like a combination of the two possibilities, and I am aware of that the two cannot be combined.

Now with closer examination, I reckon B is simply a carefully worded sentence that represents both of the possibilities, but not necessary combining the two, so therefore is correct.

Is my understanding correct?

[Kristina Moen]

I used the condition reasoning method outlined above.
However, I ruled B out, because initially B sounds like a combination of the two possibilities, and I am aware of that the two cannot be combined.

Now with closer examination, I reckon B is simply a carefully worded sentence that represents both of the possibilities, but not necessary combining the two, so therefore is correct.

Is my understanding correct?

Hi Unimelb,

You are correct. It's always possible for two sufficient conditions to have the SAME necessary condition, or even different necessary condition that fall into a larger category or have the same result. Here's an example:
If I go to the store, I will buy bread.
If I stay home, I will bake bread.
So no matter what, I will have bread! (And I'll probably eat it too, but that's another topic...) I'm not combining the sufficient conditions (which are mutually exclusive, I can't both go to the store and stay home), but I will have bread no matter which choice I make.

So here, the sufficient conditions were mutually exclusive. A plant can't be both cultivated and not cultivated. But ultimately, the necessary conditions fell into the larger category of "using the plants in ways that no other people did at the time."

[wayouteast]

I have a bone to pick with B- and it's why I didn't pick it. Why does the fact that they "ate a wider variety of wild plants than did any other people at the time" mean that they used some plants in ways that no other people did at the time?

Just because they had a wider selection does not mean that NO ONE else had access to these.
Civilization A: plants X/Y/Z
Civilization B: X
Civilization C: Y
Civilization D: Z

Sure, A has a wider selection- but that doesn't necessitate that they are the only ones with those items. So how should we simply infer this from "wider" selection without further information that there was some exclusivity of these plants?

[James Finch]

Hi wayouteast,

Must Be True questions like this need not always be 100% justified, but the correct answer will always be the conclusion most supported by the stimulus. Here, none of the other answer choices is viable:

(A) There is nothing to support this answer; it would more likely be an assumption than a conclusion

(C) The stimulus gives us nothing about how advanced these people were with wild plants, nor what that would mean, so we cannot draw any conclusions about it

(D) This is a Mistaken Reversal of the first conditional statement we were given, regarding the plants being cultivated.

(E) We have nothing that indicates the relative likelihood of the plants being wild or cultivated, and so can't support this statement.

So we're left with (B), which is admittedly far from attractive itself. However, we can get from the stimulus that if the people had cultivated the plants, it would be likely they were the first to discover agriculture and thus new uses for the plants; alternatively, having a wider variety of plants to eat could also mean that they devised new recipes unavailable to people without access to such a wide variety.

[Ian888]

Hello. I was very sure it was B but I decided to go with D only because I didn’t feel like “used some plants” was good enough to encompass eating. It makes sense when with cultivated but I wouldn’t say that using a plant is equivalent to eating a wide variety right?

Sometimes I feel like the details in the words make a lot of difference in questions and sometimes I feel like they are inconsistent. My question is how do I know when focus super narrow or broaden out when looking at the wording?

[Rachael Wilkenfeld]

Ian, it's going to vary a bit on question type and how the language is used.

Let's look at this specific scenario. The correct answer choice here uses a broad category type term ("use") to encompass multiple specific actions. Both cultivating and eating would fall into the using category. So the term "use" in a must be true answer choice is a fair use---you can use the broad covering term for the different actions described in the stimulus.

Hope that helps!