Biologist: Many paleontologists have suggested that the difficulty of

Question

Biologist: Many paleontologists have suggested that the difficulty of adapting to ice ages was responsible for the evolution of the human brain. But this suggestion must be rejected, for most other animal species adapted to ice ages with no evolutionary changes to their brains.

The biologist’s argument is most vulnerable to criticism on which one of the following grounds?

(A) It fails to address adequately the possibility that even if a condition is sufficient to produce an effect in a species, it may not be necessary to produce that effect in that species.

(B) It fails to address adequately the possibility that a condition can produce a change in a species even if it does not produce that change in other species.

(C) It overlooks the possibility that a condition that is needed to produce a change in one species is not needed to produce a similar change in other species.

(D) It presumes without warrant that human beings were presented with greater difficulties during ice ages than were individuals of most other species.

(E) It takes for granted that, if a condition coincided with the emergence of a certain phenomenon, that condition must have been causally responsible for the phenomenon.

Bunuel · Accepted Answer

EXPLANATION FROM Fox LSAT

Here, let’s rearrange the elements so that we can more easily follow the logic.

Premise: Most animal species adapted to ice ages with no evolutionary changes to their brains.  
  Conclusion: Therefore we should reject the suggestion of many paleontologists that the human brain evolved in response to ice ages.

Wait, what? The argument basically says, “Humans probably aren’t different.” But isn’t that patently ridiculous? Humans are different from other animals in many ways. Our big brains are one of the most important differences, if not the single most important difference. So aren’t paleontologists justified in speculating that something different  made  us different?

We’re asked to criticize the argument, and my first idea is, “Well, something must have made us different. So how do you know that it wasn’t a different adaptation to the ice ages that made us what we are? You seem to have assumed that if polar bear brains didn’t adapt to ice ages, then human brains couldn’t have adapted either. That seems silly, seeing as how humans are very different from polar bears.”

A) This is describing the classic sufficient vs. necessary flaw, which I didn’t spot in the argument. I’m very highly attuned to this flaw, because it is so common. So if I didn’t spot it when I read the argument, then I am almost sure it isn’t there.

B) Yep. Because polar bears didn’t change, therefore humans couldn’t have changed? That’s bullshit! Which makes this a great answer.

C) The problem with this answer is that it’s saying “necessary” instead of “sufficient.” The argument says ice ages weren’t sufficient to change polar bear brains, therefore ice ages weren’t sufficient to change human brains either. This answer says ice ages were necessary to change one species, but might not be necessary for other species. That’s different… the argument isn’t talking about necessary conditions.

D) Huh? The argument simply doesn’t do this.

E) The argument doesn’t make a correlation-therefore-causation error.

Our answer is B, because it does the best job of pointing out why the argument is silly.

whatsarc · Answer

(A) It fails to address adequately the possibility that even if a condition is sufficient to produce an effect in a species, it may not be necessary to produce that effect in  that  species. 
"That" makes it completely easy to eliminate. Its not at all comparing species.

(B) It fails to address adequately the possibility that a condition can produce a change in a species even if it does not produce that change in other species.  
Classic. Correct.

(C) It overlooks the possibility that a condition that is needed to produce a change in one species is not needed to produce a similar change in other species. 
Well, its not needed to produce similar change? The change hasnt happened so we dont know whether its needed. Eliminate

(D) It presumes without warrant that human beings were presented with greater difficulties during ice ages than were individuals of most other species. 
Irrelevant

(E) It takes for granted that, if a condition coincided with the emergence of a certain phenomenon, that condition must have been causally responsible for the phenomenon. 
Irrelevant.

VerbalBot · Answer

Automated notice from GMAT Club VerbalBot:

A member just gave Kudos to this thread, showing it’s still useful. I’ve bumped it to the top so more people can benefit. Feel free to add your own questions or solutions.

This post was generated automatically.

Biologist: Many paleontologists have suggested that the difficulty of

Prep Toolkit

Top 5 GMAT Debrief Videos

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

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards

GMAT Critical Reasoning (CR) Questions

Biologist: Many paleontologists have suggested that the difficulty of

Prep Toolkit

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

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards