Government representative: Between 1996 and 2005, the gray wolf

Question

Government representative: Between 1996 and 2005, the gray wolf population in Minnesota grew nearly 50 percent; the gray wolf population in Montana increased by only 13 percent during the same period. Clearly, the Minnesota gray wolf population is more likely to survive and thrive long term.

Environmentalist: But the gray wolf population in Montana is nearly 8 times the population in Minnesota; above a certain critical breeding number, the population is stable and does not require growth in order to survive.

The environmentalist challenges the government representative's argument by doing which of the following?

(A) introducing additional evidence that undermines an assumption made by the representative

(B) challenging the representative's definition of a critical breeding number

(C) demonstrating that the critical breeding number of the two wolf populations differs significantly

(D) implying that the two populations of wolves could be combined in order to preserve the species

(E) suggesting that the Montana wolf population grew at a faster rate than stated in the representative's argument

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RonPurewal · Answer

The environmentalist answers the representative by explaining the notion of a "critical breeding number"—basically, a minimum population size to effectively guarantee stability. Above that number, the environmentalist says, the population ought to be "stable"; in other words, populations greater than the "critical breeding number"  shouldn't be growing very quickly, if at all . (The environmentalist doesn't talk about populations below that number; for such below-critical-threshold populations, we can take this as tacit acceptance of the representative's idea that higher growth rates are better.)

So... in other words, the environmentalist brings up a   consideration   or   principle  —namely, the difference in statistical behavior of wolf populations above vs. below the "critical breeding number"—that undermines the rep's assumption that higher growth rates automatically mean a more robust population.

Choices B through E all describe things that very clearly do not happen in this passage, so choice A must be the intended correct answer.

The use of the word "evidence" in choice A, though, is incorrect.  The word "evidence" can only refer to OBSERVABLE OR MEASURABLE FACTS/DATA/OBSERVATIONS . Just think about what sorts of things could constitute "evidence" in a courtroom, for instance. (The lawyers' ARGUMENTS are NOT "evidence", although hopefully those arguments will be at least partly  based  on evidence.)
The problem here is that the answer to "WHAT, EXACTLY, undermines the representative's reasoning?" is the  principle of the "critical breeding number"  (and the differing statistical behavior of population numbers below vs. above it). General, abstract principles/rules/concepts are part of the reasoning that  uses  evidence, but they are NOT evidence themselves.

("The gray wolf population in Montana is nearly 8 times the population in Minnesota", by contrast, COULD be "evidence" for a claim. This doesn't make the phrasing of choice A accurate, though, because  this 8-to-1 ratio itself —the only thing here that could possibly be called "evidence"—isn't what undermines the rep's reasoning.
In other words, this 8:1 ratio is not  direct counterevidence  to anything that the rep is saying, so the wording of choice A is not accurate.)

quiaitaque · Answer

Hi  RonPurewal ,

I also agree and figured out that all other statements were not valid (B - D)
Yet I'm confused with A's statement on undermining an assumption made by the Government Representative. 
How can you determine that this is the Assumption :  Clearly, the Minnesota gray wolf population is more likely to survive and thrive long term.

egmat · Answer

quiaitaque

Looking at your doubt, I can see you've correctly identified (A) as the answer - great work! However, there's an important distinction to clarify about assumptions versus conclusions in Critical Reasoning.

Key Clarification: Conclusion vs. Assumption
 
What you quoted -  "Clearly, the Minnesota gray wolf population is more likely to survive and thrive long term"  - is actually the  conclusion  of the Government Representative's argument, not the assumption.

Understanding the Argument Structure: 
 
  Evidence:  Minnesota wolf population grew  50% ; Montana grew only 13% 
  Conclusion:  Minnesota's population is more likely to survive long-term 
  Unstated Assumption:  Higher growth rate = better survival prospects

What Makes Something an Assumption?
 
An assumption is an  unstated belief  that must be true for the argument to work. It's the invisible bridge between evidence and conclusion. The Representative never explicitly states "growth rate determines survival" - but this belief is  required  for their argument to make sense.

How the Environmentalist Undermines This Assumption: 
 
 The Environmentalist introduces new evidence: 
 Montana's population is  8  times larger than Minnesota's 
 Above a critical breeding number, populations are stable without needing growth

This evidence attacks the assumption by showing that  absolute population size  (not growth rate) might be the real indicator of survival. If Montana already has a large, stable population above the critical threshold, its slower growth doesn't indicate poor survival prospects.

You can practice similar Critical Reasoning questions  here - focus on "weaken the argument" and assumption-based questions to strengthen this skill.

Quick Test for Identifying Assumptions: 
Ask yourself: "What must the arguer believe (but doesn't say) to jump from their evidence to their conclusion?" That unstated belief is the assumption.

Strategic Takeaway: 
In "undermine the argument" questions, look for answer choices that introduce evidence making the unstated assumption less likely to be true - exactly what happens in choice (A) here.

Bunuel · Answer

OFFICIAL EXPLANATION

(A) introducing additional evidence that undermines an assumption made by the representative

This is the correct answer.

(B) challenging the representative’s definition of a critical breeding number

This is a Mix-Up answer. The environmentalist discusses critical breeding number, not the representative.

(C) demonstrating that the critical breeding number of the two wolf populations differs significantly

This doesn't f i t into one o f the standard trap categories. The environmentalist does mention the term “critical breeding number" but does not say that this number differs significantly. Rather, the environmentalist says that the population size differs.

(D) implying that the two populations of wolves could be combined in order to preserve the species

This is a Real World Distraction answer. It might be an interesting strategy in the real world\ but the argument doesn't mention it.

(E) suggesting that the Montana wolf population grew at a faster rate than stated in the representative’s argument

This is a Mix-Up answer. The environmentalist does mention a number, but that number does not represent a rate o f growth.

Government representative: Between 1996 and 2005, the gray wolf

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GMAT Critical Reasoning (CR) Questions

Government representative: Between 1996 and 2005, the gray wolf

Prep Toolkit

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

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