B it is

I would also go with B.

As you state, C, D, and E are out because obviously, "agriculture began in the Highlands less than 2000 years ago" is a statement of fact, not a position.

So between A and B...

A. The first is evidence that has been used in support of a position that the ecologist rejects; the second is a finding that the ecologist uses to counter that evidence.

The fact that agriculture in the Highlands is less than 2,000 years old is evidence used in support of the position the ecologist supports not rejects -- our clue here is the "however" preceding the question. On that alone, we can eliminate this, but the second statement is wrong too -- the second bold face does not counteract anything about agriculture being less than 2000 years old. Eliminate.

B. The first is evidence that, in light of the evidence provided in the second, serves as grounds for the ecologist’s rejection of a certain position.

Since we know we're between A and B, this is simple. Basically, this states that the two boldfaced statements support the ecologist's rejection of the widely accepted position, which they do.

Plenty of votes for B

B is the correct answer.

For reasons please go through the posts above me.

@myohmy : Its good to see you after a long time.
How was your Interview by the way??

Genetic Mutation

OA-A

The conclusion is All mutations are random.

Only option C fills a logical gap between the premise in the argument and the conclusion. If genetic mutations in bacteria are random, then genetic mutations in all other forms of life are random.

Thanks Karan! I know I owe you an email, I've been super busy. Haven't had the interview yet.

This one is tough -- it came down to A and C for me but I went with A.

In experiments in which certain kinds of bacteria were placed in a generous supply of nutrients, the populations of bacteria grew rapidly and genetic mutations occurred at random in the populations. These experiments show that all genetic mutation is random.

Which one of the following, if true, enables the conclusion to be properly drawn?

The question here is asking us to provide the crucial link that allows us to draw a (pretty big) conclusion that all genetic mutation is random -- in other words, it's looking for a "must be true" in order to ensure the conclusion is true.

We know that the experimental bacteria mutated at random and somehow, this means that all genetic mutation occurs at random. We're just looking for what that "somehow" is.

A) Either all genetic mutations are random or none are random.

This one is interesting. If this is true, then because the genetic mutation occurred at random in the experiment, all other genetic mutation must occur at random. This is the only statement that has to be true if we consider the evidence provided and want to ensure it supports a conclusion that must be true.

B) The bacteria tested in the experiments were of extremely common forms.

This is out of scope. If they were unusual forms it wouldn't make the conclusion any more or less valid. Eliminate.

C) If all genetic mutations in bacteria are random, then all genetic mutations in every other life form are random also.

This one is also interesting, since the "all" in the statement's conclusion alludes to the fact that we should be considering other life forms, not just bacteria. However, the experiment does not prove that all genetic mutations in bacteria are random, just that this experiment's genetic mutations were random. Since the answer begins with "if" and we haven't supported that clause by the evidence, this doesn't ensure that the conclusion is valid. Eliminate, but this is tricky.

D) The kind of environment in which genetic mutation takes place has no effect on the way genetic mutation occurs.

Even if this is true, there are a whole host of other factors that could affect the way genetic mutation occurs, so we couldn't reasonably conclude that all genetic mutation is random. Eliminate.

E) The nutrients used were the same as those that nourish the bacteria in nature.

This is out of scope and irrelevant. Eliminate.

One more for A.

Premise--> CERTAIN kinds of bacteria....populations of bacteria grew rapidly.....genetic mutations occurred at random in the populations.

Conclusion --> ALL genetic mutation is random.

Choice A fills the gap appropriately. C talks about ALL bacteria with a necessary condition indcator IF. But premise talks about CERTAIN bacteria.

Hello Friends,

Sorry for the Late reply. I was busy improving my SCs(but unfortunately dont think they have improved even a bit )

Here is the OA[spoiler](A)[/spoiler]

OE: This question is a perfect example of scope-shift. The evidence is that, in one particular environment, some types of bacteria experienced random mutations. The conclusion is that all genetic mutation is random. The credited response needs to link this specific example to the general conclusion.
Combine the stimulus with (A). The stimulus states that some genetic
mutations are random, and (A) states that either all mutations are random or none are. If some mutations are random, then all mutations must be random; the alternative option isn’t possible. If (A) is true, all genetic mutations are random, which is our conclusion

Why C is wrong

Since the stimulus doesn’t tell us that all genetic mutation in bacteria is random (it only mentions certain kinds of bacteria), answer choice (C) doesn’t allow us to conclude anything. (C)’s conclusion would only be true if all genetic mutations in bacteria were random.


Hope this Helps.

Now time for some Bold Face Questions

I found this question on another forum and there was a big debate about the OA. Lets see are we going to have a single opinion or again a debate.

Since it has become known that several of a bank’s top executives have been buying shares in their own bank, the bank’s depositors, who had been worried by rumors that the bank faced impending financial collapse, have been greatly relieved. They reason that since top executives evidently have faith in the bank’s financial soundness, those worrisome rumors must be false. They might well be overoptimistic, however since corporate executives have sometimes bought shares in their own company in a calculated attempt to dispel negative rumors about the company’s health.

In the argument given, the two boldfaced portions play which of the following roles?

A. The first summarizes the evidence used in the reasoning called into question by the argument; the second states the counterevidence on which the argument relies.

B. The first summarizes the evidence used in the reasoning called into question by the argument; the second is an intermediate conclusion supported by the evidence.

C. The first is an intermediate conclusion that forms part of the reasoning called into question by the argument; the second is evidence that undermines the support for this intermediate conclusion.

D. The first is an intermediate conclusion that forms part of the reasoning called into question by the argument; the second is the main conclusion of the argument.

E. The first is an intermediate conclusion that forms part of the reasoning called into question by the argument; the second states a further conclusion supported by this intermediate conclusion.

B for me

the first bf is preceded by "since" so the first bf is an evidence that is questioned.

C, D, E are out as they say the first bf is a "conclusion'

between A and B, A is out as it calls the 2nd bf an "evidence". the 2nd bf is a conclusion as it is followed by "since"

Was debating between B & D. But selected B. Curious to see the OA and explanation.

B. The first summarizes the evidence used in the reasoning called into question by the argument; --> CORRECT preceeded by a premise indicator SINCE

the second is an intermediate conclusion supported by the evidence. --> Skeptical about this. If this were intermediate conclusion, where is the main conclusion?

D. The first is an intermediate conclusion that forms part of the reasoning called into question by the argument; --> INCORRECT preceeded by a premise indicator SINCE

the second is the main conclusion of the argument. --> CORRECT as it appears to be the MAIN conclusion of the argument.

its OBVIOUSLY D...since the second bold face part HAS to be the main conclusion. Although i dont agree with the first being an intermediate "conclusion".. It is presened as evidence rather than a coclusion.

Bad question though.

Well, as I said, the question is controversial, I got this question from another foum
https://www.urch.com/forums/gmat-critica ... mment.html

https://www.urch.com/forums/gmat-critica ... d-one.html

I do have this question in some notes. The OA given is E,but even I don't trust the source.

To my opinion, A and B are strong contenders, B wins over A for the reasons cited by Scooby.

i disagree with OA as E

Should be B

first sentence can never be a conclusion... its an evidence

Sorry for being not so regular to this thread.

I came up with this question, I think it is simple, but I could satisfy myself with the OA. Need your opinions.