GMAT CLUB OLYMPICS: David: Humans did not evolve from an aquatic ances

Question

David: Humans did not evolve from an aquatic ancestor. Chimpanzees, our closest living relatives, share over 98 percent of our DNA, and they don’t swim or spend time in the water unless they have to. They even use leaves to soak up water to drink, rather than cup their hands.

Lynn: True, but we also have a layer of fat under our skin, which would make us unique in the animal kingdom as the only non-aquatic species that has evolved such fat, not to mention that fatty tissue is 90 percent as dense as water, helping us float and thereby conferring a survival advantage that would be useless outside of water.

Lynn responds to David’s argument by

(A) agreeing with him but adding counterarguments from opponents of that view.
(B) conceding that his evidence is valid but drawing attention to other evidence that refutes his argument.
(C) initially agreeing with him but then changing her mind by drawing upon comparisons.
(D) ignoring it and attacking the implications of his facts to support her counterargument.
(E) acknowledging the facts he uses to support his argument but offering additional information to consider without herself making a conclusion.

V33-01

AndrewN · Accepted Answer

A friendly hello to all Olympians again. One of my clients told me that his recent GMAT™ Online test had a lot of dialogue-based CR questions, so maybe this is better practice than you think. Whenever you see two names like this, you can anticipate that the two snippets of dialogue will in some way comment on each other, most of the time presenting some divergence of opinion.

David  states his position (a.k.a. argument, claim, or conclusion) right upfront in the first line and then goes on to support this claim with a few premises, but they all boil down to a comparison between  chimpanzees, our closest living relatives , and, well, ourselves, human beings. Namely, chimpanzees show a dislike for touching  water , so humans must not have evolved  from an aquatic ancestor .

Lynn  begins with  true . Now, what that word extends to is up for debate: the entire argument, the premises, or just one premise. Regardless, she then draws attention to  humans  and an apparent  survival advantage  in buoyancy that is conferred by our subcutaneous fat.

How can we summarize her response in relation to what David says?

Who are these  opponents ? Lynn neither mentions others by name nor suggests their presence through a word such as  hypothesis  or  theory . It does seem clear that these new facts run counter to the ones David used to establish his claim, but evidence on its own does not form a counterargument. Now, if you are conservative like me, you might hang on to this option while you searched for one that was less objectionable, but this is a middle-of-the-road answer, probably not what we want in the end.

Unless we know for sure that humans  did , in fact, evolve from an aquatic ancestor, we cannot say that the information Lynn brings up  refutes his argument . Again, there are more facts to consider, but the jury is still out on the verdict. Watch out for overreaching language.

If you are reading too close to the text, you might misinterpret the opening two words that Lynn utters:  true, but ... The overall context of her lines provides no indication that she agreed with the original claim but then pulled an about-face. You can almost envision the word  although  or  while  ahead of her portion of dialogue, and that frame sounds more like a concession, perhaps something to say to cushion the information that is about to follow.

Not only does Lynn not  ignore  the original argument—she clearly addresses human evolution, relative to an aquatic ancestor—but she does not launch into an  attack  against that argument either. We would expect to see more judgmental language, such as  poorly    or  ill   , to qualify labeling her lines an attack. I will discuss this notion of  her counterargument  below. In all, this should be an easy elimination, given what we have seen up to this point.

All of this is difficult to argue against. Lynn does acknowledge what David said. We are not entirely sure what  true  may apply to, as I wrote above, but it seems reasonable to infer that it covers the information David used to support his argument, since Lynn then provides information on the same general topic. Does Lynn make a  conclusion ? No. I cannot point to any part of her speech and say,  There is your conclusion . If we go from comma to comma, all one extended line, we get the following:

true —an acknowledgement of some sort;

but we also have a layer of fat under our skin —factual information about the bodily composition of human beings;

which would make us unique in the animal kingdom as the only non-aquatic species that has evolved such fat —a concession that if David is  correct , it would defy expectation, based on our aforementioned bodily composition;

not to mention that fatty tissue is 90 percent as dense as water —another fact, this one about fat;

helping us float and thereby conferring a survival advantage that would be useless outside of water —a modifier, commenting on the previous fact.

In short, no argument or conclusion is ever on display. Lynn brings up points, nothing more.

Between (A) and (E), there is no contest. The beginning of (A) looks worse than its counterpart:  agreeing with him . To what extent does Lynn agree with David? It is much safer to say that she acknowledges something in his argument. And whereas we had to come to terms with  opponents of that view  before, now we have a clearcut lack of a counterargument in (E), as detailed above. (E) is the better option, so that is why we should choose it.

Note that these "Method of Reasoning" questions share certain labeling characteristics with boldface questions. If you are interested in learning how to spot arguments and premises, these types of questions can help.

As always, good luck with your studies. I hope you enjoyed this one.

- Andrew

chrisjonatan · Answer

(A) agreeing with him but adding counterarguments from opponents of that view.
 Incorrect, she doesn't counterarguments from opponents of that view.

(B) conceding that his evidence is valid but drawing attention to other evidence that refutes his argument.
 Lynn doesn't refute David argument. Incorrect

(C) initially agreeing with him but then changing her mind by drawing upon comparisons.
 Lynn doesn't agree with David. Incorrect

(D) ignoring it and attacking the implications of his facts to support her counterargument.
 Lynn is not ignoring it. Incorrect

(E) acknowledging the facts he uses to support his argument but offering additional information to consider without herself making a conclusion.
 Correct. Lynn acknowledge the fat, spill other facts, and she didn't make any conclusion

IMO, E

VirFortis · Answer

D : humans -> from chimps -> chimps no traits of aquatic, so humans non-aquatic.
L : agree with the facts -> additional info : fat that makes survival under water easier - else useless.

the evidence provided can help D to consider the possibility of human being aquatic in light of the new info.

- doesn't add counterarguments to what D says. Eliminate.
 
other evidence doesn't refute D's argument. Eliminate.
 
she doesn't change her mind. she just adds more info for D's reconsideration. Eliminate.
 
doesn't ignore, doesn't attack. Eliminate.
 
acknowledges - correct.
offers additional info - correct.
doesn't draw conclusion on the basic argument - are humans aquatic? - correct.

Ans. E.

sumitkrocks · Answer

IMO  (E)  Is correct

David: Humans did not evolve from an aquatic ancestor. Chimpanzees, our closest living relatives, share over 98 percent of our DNA, and they don’t swim or spend time in the water unless they have to. They even use leaves to soak up water to drink, rather than cup their hands.

Lynn: True, but we also have a layer of fat under our skin, which would make us unique in the animal kingdom as the only non-aquatic species that has evolved such fat, not to mention that fatty tissue is 90 percent as dense as water, helping us float and thereby conferring a survival advantage that would be useless outside of water.

Lynn responds to David’s argument by

(A)  agreeing with him but adding counterarguments from opponents of that view.

Lynn did not add counterarguments from opponents of David's view

(B) conceding that his evidence is valid but drawing attention to other evidence that refutes his argument. 
Lynn did not present fact to refute David's view

(C) initially agreeing with him but then changing her mind by drawing upon comparisons. 
Lynn did not make comparison

(D) ignoring it and attacking the implications of his facts to support her counterargument. 
Lynn did not ignore David's argument

(E) acknowledging the facts he uses to support his argument but offering additional information to consider without herself making a conclusion.
 
Yes, this is correct 
Lynn agreed and presented additional information that supports counter theory but Lynn did not make any conclusion rather raised a question.

RandomStoryteller · Answer

David's Argument : 
Conclusion: Humans did not evolve from an aquatic ancestor.
Why? The reason stated is that Humans are closely related to Chimpanzees and they don't swim, so humans don't have the aquatic ancestor.

Lynn's Argument: Lynn actually agrees with the fact, however, gives other information which alludes to the fact that humans have a unique ability to float. No concrete conclusion is made.

(A) agreeing with him but adding counterarguments from opponents of that view. ( Incorrect: Lynn agrees with the argument but does not use counterarguments from the opponents of that view. He does refute the facts stated by David)

(B) conceding that his evidence is valid but drawing attention to other evidence that refutes his argument. ( Incorrect: Confused with this option but I think Lynn does not refute the conclusion clearly stated by David. He does provide information that alludes to the fact that humans can float but no such conclusion is made which says humans are descendants of aquatic species)

(C) initially agreeing with him but then changing her mind by drawing upon comparisons. ( Lynn does not change her mind , simply states additional information).

(D) ignoring it and attacking the implications of his facts to support her counterargument. (Lynn does not ignore David's argument)

(E) acknowledging the facts he uses to support his argument but offering additional information to consider without herself making a conclusion. ( Yes Correct. Lynn states additional information without actually making any conclusion)

avinashiitp · Answer

A-wrong- Lynn is not adding counterarguments from opponents of that view, rather presenting new evidence to weaken but she does not claim anything
C-wrong -not changing changing her mind by drawing upon comparisons (see A)
D-Wrong, not ignoring rather acknowledges it.

Only B and E
B - wrong - other evidence does not refutes his argument rather weakens, she does not claim otherwise rather agrees with him without claiming anything

Hence E

gmatlover1010 · Answer

Lynn says "Hey All you said true.. But check out this. We've got FAT under the skin. No animal that has a non aquatic ancestor has this.. Also this fat helps us float, a characteristic of this fat which would be useless outside of water. " 
Lynn says a whole bunch of facts but no conclusive remarks. I'm already leaning towards E. But I need to look into the reemaining options.

A - Not countering David's facts - OUT
B- The facts stated by Lynn isn't against the facts presented by David; they are both targeting different aspects - OUT 
C- No , there is no change of mind observed - OUT
D - No the implications are not being targeted. - OUT 
E - fits perfectly. 
 
IMO E

MV94 · Answer

Logical Map:

D: chimps don't swim & don't touch water unless absolutely necessary -> humans evolved from chimps as seen by 98% DNA overlap -> humans didn't come from aquatic species

L: true, but -> humans have fat -> all other species with aquatic ancestors have fat, fat is 90% as dense as water -> implies used to float

How did Lynn respond?

Pre-thinking: she cites other facts that imply D's conclusion is incorrect, without directly attacking on of his premises. She doesn't explicitly disagree with D or provide her own conclusion, rather she starts by saying true - which means she doesn't disagree with his premises

(A) agreeing with him but adding counterarguments from opponents of that view. - I am not sure we can definitively say she agrees or disagrees with D's conclusion. Eliminate.
(B) conceding that his evidence is valid but drawing attention to other evidence that refutes his argument. - this is close, but again I am not sure we can definitively say she is for or against his conclusion, she is merely stating the opposing view. Eliminate. 
(C) initially agreeing with him but then changing her mind by drawing upon comparisons. - I think saying that she changes her mind is a stretch here. Eliminate.
(D) ignoring it and attacking the implications of his facts to support her counterargument. - she acknowledges his point of view by starting with "true." Eliminate. 
 (E) acknowledging the facts he uses to support his argument but offering additional information to consider without herself making a conclusion. - yes, this is exactly it IMO. The best answer choice IMO and my selection.

rvgmat12 · Answer

Lynn responds to David’s argument by

(A) agreeing with him but adding counterarguments from opponents of that view.
No. We don't know what are the counterarguments from opponents of David's view

(B) conceding that his evidence is valid but drawing attention to other evidence that refutes his argument.
No. Lynn's argument doesn't refute the facts quoted by David

(C) initially agreeing with him but then changing her mind by drawing upon comparisons.
Incorrect. Lynn doesn't change her mind

(D) ignoring it and attacking the implications of his facts to support her counterargument.
Incorrect. Lynn doesn't attack facts quoted by David

(E) acknowledging the facts he uses to support his argument but offering additional information to consider without herself making a conclusion.
Correct. Lynn's argument doesn't have a conclusion but offers additional evidence for consideration

Vjajo · Answer

David: Humans did not evolve from an aquatic ancestor. Chimpanzees, our closest living relatives, share over 98 percent of our DNA, and they don’t swim or spend time in the water unless they have to. They even use leaves to soak up water to drink, rather than cup their hands.

Lynn: True, but we also have a layer of fat under our skin, which would make us unique in the animal kingdom as the only non-aquatic species that has evolved such fat, not to mention that fatty tissue is 90 percent as dense as water, helping us float and thereby conferring a survival advantage that would be useless outside of water.

Lynn responds to David’s argument by

(A) agreeing with him but adding counterarguments from opponents of that view.
(B) conceding that his evidence is valid but drawing attention to other evidence that refutes his argument.
(C) initially agreeing with him but then changing her mind by drawing upon comparisons.
(D) ignoring it and attacking the implications of his facts to support her counterargument.
(E) acknowledging the facts he uses to support his argument but offering additional information to consider without herself making a conclusion.

Conclusion by David: Humans did not evolve from aquatic ancestors.
Lynn: Agrees to the conclusion of David by saying "True". The presence of fat under the skin makes humans unique and be able to float which can be used as a survival advantage.

The option which agrees with Lynn's response is option E. She agrees with him but does not refute it or make any other conclusion.

Crytiocanalyst · Answer

(A) agreeing with him but adding counterarguments from opponents of that view.
we cannot conclude what opponents have in their mind out of context

(B) conceding that his evidence is valid but drawing attention to other evidence that refutes his argument.
The argument doesn't refute the claim that chimpanzees do not share DNA but just provides additional information

(C) initially agreeing with him but then changing her mind by drawing upon comparisons.
What her mind plays is out of context

(D) ignoring it and attacking the implications of his facts to support her counterargument.
She's not all ignorant but rather acknowledges

(E) acknowledging the facts he uses to support his argument but offering additional information to consider without herself making a conclusion.

This exactly what she's intenfing to

Therefore IMO E

c93liu · Answer

My answer is E).

Process of elimination:

A) - "from opponents of that view" is wrong. The views conveyed seems to be Lynn's.

B) - "other evidence that refutes his argument" - don't know about that, seems to weaken rather than refute.

C) - "initially agreeing with him but then changing her mind" - first part of Lynn's response seems to concede on the validity of the evidence rather than a wholesale agreement with David on his conclusion.

D) - "ignoring it" is wrong.

E) - seems to be the best among the 5. She stops short of making the conclusion that "humans might evolve from an aquatic ancestor". "thereby conferring a survival advantage that would be useless outside of water" can be considered an intermediate conclusion or a premise, but not the conclusion.

JonShukhrat · Answer

I like how Lynn responds to David’s argument. 
No argument, no dispute, no drama, no evident opposing conclusion. 
Simply leaving him among facts. True professional.

David started with his conclusion: Humans did not evolve from an aquatic ancestor.
What he next offered is a human trait similar to that of non-aquatic animal: DNA

(A) agreeing with him but adding counterarguments from opponents of that view.

As we have alredy discussed above Lynn doesn’t bring any counterargument. There is nothing in her speech told against what David says.

(B) conceding that his evidence is valid but drawing attention to other evidence that refutes his argument.

The fact that people have a certain type of fat doesn’t necessarily refute the claim that we never lived under water. It simply adds another evidence that must be into equation.

(C) initially agreeing with him but then changing her mind by drawing upon comparisons.

Again, she didn’t change her mind. She simply agreed to the fact that people have similarities with chimpanzees. She didn’t say anything against that.

(D) ignoring it and attacking the implications of his facts to support her counterargument.

“ignoring” and “attacking” have nothing to do with Lynn said. She dais “true”, so she didn’t ignore him.

(E) acknowledging the facts he uses to support his argument but offering additional information to consider without herself making a conclusion.

Correct choice. What Lynn offers is another human trait that non-aquatic animals lack in: fatty tissue, 90 percent as dense as water
Also note that Lynn starts with “true”. 
So Lynn acknowledges that chimpanzees have something to do with humans.
But still she shows that we have a trait that would help us not sink. 
Keeping this in mind, let’s move to choices.

So E

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GMAT CLUB OLYMPICS: David: Humans did not evolve from an aquatic ances

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GMAT CLUB OLYMPICS: David: Humans did not evolve from an aquatic ances

Prep Toolkit

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