Q22 - Biologist: Some speculate that

[linzru86]

I'm having a hard time wrapping my head around this one. I thought I understood the argument but I can't see how D is true. In fact, I see the answer as being the opposite of what D says.

[ManhattanPrepLSAT1]

The reason why you see it as the opposite is the way the beginning of the last sentence is phrased. It says, "the only kind of evolutionary pressure that can reduce the size of goats is that resulting from small goats having greater reproductive success." This statement basically says that no other evolutionary pressure could have had such an effect.

Answer choice (D) says that the evolutionary pressure to ensure a diverse gene pool is not the kind of evolutionary pressure that could have such an effect.

Here's an analogy.

Stimulus
The only one with a key is John.

Answer choice (D)
Sarah does not have a key.

I hope that helps you see this one!

[ccalice21]

I think the reason you consider right answer as opposite of D is that D says "increasing" while the corresponding word in the last sentence is "reduce".

In order to understand why this change is legitimate, you need to read and understand the second-to-last sentence in the question stem.

Then, you will see that the argument is saying that the only kind of evolutionary pressure that can CHANGE the size ... is to change reproductive success accordingly.

And obviously you can either increase or reduce in order to change.

The analogy with the key really helps, but you need a step further.

[peg_city]

Why is A wrong?

[anjelica.grace]

Why is A wrong?

(A) is wrong because it contradicts the biologist and instead supports the view he is trying to refute, i.e. that the high frequency of small goats on the islands is due to the need for genetic diversity [see the first sentence].

The biologist's view is that reproductive success, and only reproductive success, explains the high frequency of a particular gene.

Notice there's two explanations or theories in the stimulus for the high frequency of small goats: 1) need for genetic diversity and 2) reproductive success.

(A) aligns itself with the first theory, whereas the biologist proposes the second.

Hope that helps! Please correct me if my explanation is wrong or unclear.

[hayleychen12]

Can anyone further breakdown the stimulus?

Totally lost !!!

[a8l367]

Some says that
evol pres for DGP* lead to MSG**
However
only evol pres resulted from SGAGR*** whould lead to MSG**

most support
D) evol pres to for DGP* do not lead to MSG**
A) evol pres to for DGP* could lead to MSG**

Why not A???

*Diverse gen pool
**Many small goats
***Small goats achieving greater reproductive

[ohthatpatrick]

(A) is the opposite of (D).

The rule we're given for "frequency of a trait in a population" is:

If we aren't talking about reproductive success, then we're not talking about something that could influence the frequency of a trait in a population."


Is "evolutionary pressure to ensure a diverse gene pool" talking about reproductive success?

No. A diverse gene pool just means you have a lot of organisms with varied DNA.
Reproductive success is saying "organisms of a population with a specific ingredient in their DNA tend to have more/less reproductive success".

Since "diverse gene pool" is not talking about "reproductive success", "diverse gene pool does not influence the frequency of a trait.

(D) says DOES NOT have the effect (correct)

(A) says COULD HAVE the effect (incorrect)

[LeeJ891]

(A) is the opposite of (D).

The rule we're given for "frequency of a trait in a population" is:

If we aren't talking about reproductive success, then we're not talking about something that could influence the frequency of a trait in a population."


Is "evolutionary pressure to ensure a diverse gene pool" talking about reproductive success?

No. A diverse gene pool just means you have a lot of organisms with varied DNA.
Reproductive success is saying "organisms of a population with a specific ingredient in their DNA tend to have more/less reproductive success".

Since "diverse gene pool" is not talking about "reproductive success", "diverse gene pool does not influence the frequency of a trait.

(D) says DOES NOT have the effect (correct)

(A) says COULD HAVE the effect (incorrect)

Isn't it possible that the reproductive success of the goat is improved because the goats are small, in which case answer A would be correct. I see that the Biologist is contrasting his/her point with the "some speculate" group's contention, but he/she doesn't explicitly say that their view is wrong. To me, both answer D and A require you as the test taker to make an assumption, whether you got the answer correct depends on which assumption you as the LSATer made

Can you explain if I am wrong? Thanks so much

[Laura Damone]

First, please excuse the delayed response. This one must have slipped through the cracks amidst all the craziness of the past few weeks.

Second, I think honing in a bit more on the question stem can help you out. Many "Most Strongly Supported" questions have a stem that looks like this: The statements above, if true, lend most support to which of the following?

In those questions, you need to take the sum total of what was said in the stimulus and try to derive an answer.

In this question, however, the stem asks us which answer is most supported by the biologist's view. His/her view begins at the pivot word "however." The part that comes before "however" is the opposing point. The correct answer, therefore, can't be derived from that part of the stimulus.

Answer choice A is essentially a paraphrase of the opposing point. Yes, some people believe it, so yes, it could be true, but it doesn't align with the biologists's view, and that's what the question is asking.

Hope this helps!