The Canadian elk has traditionally been limited in its geographic rang

Question

The Canadian elk has traditionally been limited in its geographic range by the presence of elderberries, its primary source of food, which only grow up until a certain point in the tundra. A recent rise in temperatures, however, has seen a spread in the growth of elderberries northwards into the tundra. Therefore, the overall range of the Canadian elk can be expected to increase.

Which of the following, if true, best casts doubt on the argument?

A. In addition to elderberry, the Canadian elk also consumes loganberries, which are expected to also begin growing at more northerly latitudes.

B. During the summer months, many Canadian elk are hunted both for sport and for their meat.

C. The grizzly bear, the Canadian elk’s primary predator, has also started moving north into the tundra.

D. The permafrost, the region above the tundra, in which the temperatures never reach above freezing, will unlikely see elderberry growth.

E. Increasing temperatures have created conditions too warm for elderberry growth in the southern half of the Canadian elk’s traditional territory.

bb61 · Accepted Answer

we have scope shift in this argument. 
it explains that a recent rise in temp. has  spread the growth of Canadian elk's food northward . 
and then concludes that  the overall range  of the Canadian elk  can be expected to increase . 
for the argument to hold true the author must assume that the current range will not decrease. 
and E address this issue.

Which of the following, if true, best casts doubt on the argument?

A) In addition to elderberry, the Canadian elk also consumes loganberries, which are expected to also begin growing at more northerly latitudes. 
the argument talked only about elderberry

B) During the summer months, many Canadian elk are hunted both for sport and for their meat.
the reason for hunting Canadian elk is out of the scope of the argument

C) The grizzly bear, the Canadian elk’s primary predator, has also started moving north into the tundra. The permafrost, the region above the tundra, in which the temperatures never reach above freezing, will unlikely see elderberry growth.
the argument talks about the range of Canadian elk, not its predator!

D) The permafrost, the region above the tundra, in which the temperatures never reach above freezing, will unlikely see elderberry growth.
the argument talks about the growth of elderberries northwards into the tundra.... the region above tundra is out of scope

E) Increasing temperatures have created conditions too warm for elderberry growth in the southern half of the Canadian elk’s traditional territory.

KyleWiddison · Answer

The Canadian elk currently lives in the southern part of the tundra. The conclusion of the argument states that the presence of elderberries in the north will cause the range (overall size of where the elk lives) to increase. We are trying to weaken that conclusion, so the answer will provide information that will make that conclusion seem invalid (or wrong).

Answer choice E states that the southern area of the tundra (where the elk currently live) has temperatures that are too high for elderberry growth. This would mean that elk can't continue to live in the south. The elk aren't seeing an expansion of their living territory to include both the north and the south - they are seeing their living area shift from the south to the north. This information about the elderberries in the southern tundra invalidates the conclusion that the range of elk will increase, making E the correct answer.

KW

vaggar4 · Answer

I marked C. How can E be correct? It talks about southern part and not northern.

UJs · Answer

Argument : { elderberry growth in North  -->  increase Canadian elk’s territory }: Weaken it

A) loganberries -  not related 
B) many Canadian elk are hunted -  doesn't matter, even if few elks are now able to move along and cover the new area then argument still is valid.(not a weakener).
 
C) The grizzly bear, moving north -  doesn't mean it will actually do some harm (unless we assume something more )

D) The permafrost region, will  unlikely  see elderberry growth -  note unlikely (so close, but not 100% sure), hence not a solid weakener.

E) Increasing temperatures  have created conditions too warm for   elderberry growth in the southern half of the Canadian elk’s traditional territory. -  Note in this case its sure and certain that elderberry growth in south is not possible (not using unlikely as in D) --  Correct

Ans : E

aj33 · Answer

increase in range means that the starting point is fixed and the ending point moves up the line.

Which of the following, if true, best casts doubt on the argument?

A)In addition to elderberry, the Canadian elk also consumes loganberries, which are expected to also begin growing at more northerly latitudes. 
This gives us no reason to believe that the range will not increase
B)During the summer months, many Canadian elk are hunted both for sport and for their meat.
no reason whyy the range will not increase
C)The grizzly bear, the Canadian elk’s primary predator, has also started moving north into the tundra. 
Increase in range yea./nah dunno

D)The permafrost, the region above the tundra, in which the temperatures never reach above freezing, will unlikely see elderberry growth.
where is this region far far away in the north. i dunno Increase or decrease no idea.
E)Increasing temperatures have created conditions too warm for elderberry growth in the southern half of the Canadian elk’s traditional territory.

for range to not increase if it moves up. the starting point will also move up. therefore wither the range is less or the same but it does not increase

chesstitans · Answer

each of option choices in this question contains the common pattern that keeps appearing in other CR questions. The issue here is the key word. Here, "overall range" is what makes E correct.

aragonn · Answer

Official Explanation
Answer: (E)

The argument is that the elk’s territory will grow because the elderberry, its primary food source, is expected to grow further north. (E) calls this conclusion into question because if elderberries can no longer grow in the southern half of the elk’s territory, then the elk's range has been truncated. There is no information concerning how far north the new territory will reach.

(A) suggests that elk will be very well provided for, diet-wise, as they move into the tundra.

(B) is just a general fact that does not relate to the argument.

(C) may be tempting but remember that just because the grizzly bear will continue to prey on the elk as it moves into the tundra does not mean there will be no elk in the tundra.

(D) is out of scope because the argument only concerns the tundra, not the area north of the tundra.

FAQ: Can you explain choice A a bit more?

A: (A) reads: In addition to elderberry, the Canadian elk also consumes loganberries, which are expected to also begin growing at more northerly latitudes.

The key here is that another of the elk's food sources is going to grow in the north. This simply strengthens the argument that the elk's range will increase (into the north).

In order to weaken the argument, we need to look for a reason that the elk's range would actually not increase. (A) does not provide such a reason -- it provides another reason why the elk's range will increase.

FAQ: Can you explain choice C a bit more?

A: (C) may be tempting, but remember that just because the grizzly bear will continue to prey on the elk as it moves into the tundra does not mean there will be no elk in the tundra. The grizzly bears will not stop the elk from moving north. Rather, the grizzly bear would follow the elk north. The elk's range would still expand into new regions.

FAQ: What about D?

A: This isn't negating the facts of the passage. The passage says the elderberries have spread into the TUNDRA, but (D) is talking about ABOVE the tundra...in other words, even farther north of the tundra.

So the elderberries are still spreading. (D) doesn't contradict this, it just puts one kind of limit on how far/how much the elderberries and therefore the elk could spread. But this doesn't weaken the argument that the elk's territory will increase at least to some degree. They are still spreading to part of the tundra.

dcummins · Answer

Imagine that the Elk are in the centre of a circle and their range is the radius.

The Elk's range would decrease or stay the same if berry growth in the south remains unchanged.

ricardorr04 · Answer

Hi - I got E in 1:40 seconds.

What level is this? 700 or 600? trying to understand the difficulty to see where I stand.

thank u very much

Kapil1650 · Answer

Though the official explanation is fair enough but it would not be east job to opt for E easily as the option talks about southern part and most of the times such answer choices are opted out due to- out of context thought !

Posted from my mobile device

Posted from my mobile device

PRamesh2008 · Answer

The Canadian elk has traditionally been limited in its geographic range by the presence of elderberries, its primary source of food, which only grow up until a certain point in the tundra. A recent rise in temperatures, however, has seen a spread in the growth of elderberries northwards into the tundra. Therefore, the overall range of the Canadian elk can be expected to increase.

Which of the following, if true, best casts doubt on the argument?

It's important that the argument's conclusion be kept in perspective , while analysing the options (using POE). The conclusion of the Argument is : overall RANGE of the Canadian elk can be expected to increase.

Let's now use the POE method to nalyse the options one by one..

Let's now use the POE method to nalyse the options one by one..

A. In addition to elderberry, the Canadian elk also consumes loganberries, which are expected to also begin growing at more northerly latitudes.

Out of scope, since the conclusion is based on increase in Range of Canadian Elk on basis of elderberries as their primary source of food, and NOT loganberries

B. During the summer months, many Canadian elk are hunted both for sport and for their meat.

Just a piece of additional information..doesn't affect the conclusion in any manner.

C. The grizzly bear, the Canadian elk’s primary predator, has also started moving north into the tundra.

Canadian elk's survival primarily depends on its access to elderberries, which now grow northwards..Predators' movement northwards may mildly affect but not restrict the movement of Canadian elk, since the old 'survival techniques' employed against the predators will enable the Canadian elks to save themselves from predators. Strengthens the argument's conclusion, hence doesn't cast any doubt.

D. The permafrost, the region above the tundra, in which the temperatures never reach above freezing, will unlikely see elderberry growth.

Irrelevant, since region above the tundra is not being discussed to reach the conclusion.

E. Increasing temperatures have created conditions too warm for elderberry growth in the southern half of the Canadian elk’s traditional territory.
   If the southern half of Canadian elk’s traditional territory is too warm to affect survive, then it's evident that the Canadian elk's move northwards in search of elderberries will not lead to an overall increase of the range of Canadian elk..in turn, negating the argument's conclusion that the overall range of the Canadian elk can be expected to increase.

Hence, (E) is the correct choice

Hope this helps

VerbalBot · Answer

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The Canadian elk has traditionally been limited in its geographic rang

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The Canadian elk has traditionally been limited in its geographic rang

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