Q8 - Delta green ground beetles

[ebrickm2]

I can't even think about this question right now. I despise it, help.

[ManhattanPrepLSAT1]

We're asked to strengthen the conclusion drawn in the argument.

The conclusion reached is that the drop in observed delta green ground beetles is not the result in an overall drop in delta beetle population.

The evidence for this is that the beetles remain motionless unless it rains, and in 1985 it was wet, while in 1989 it was dry.

The major assumption of this argument is that one cannot see the beetle, unless the beetle is in motion - perfectly expressed in answer choice (A).

(B) weakens the argument, maybe a little, because now the frogs are around water all the time, so who cares whether 1985 was wet year.
(C) is irrelevant. Why delta ground beetles move around is not important relative to whether or not we can see them.
(D) is irrelevant. It is not important whether or not these beetles are rare or common.
(E) is tempting because it brings in the idea that maybe the drop in population was due to being preyed on by another animal. However, this answer choice does not preclude the delta ground beetle from being preyed on, just from being the main diet of another animal. So had this choice, said that the beetle is not preyed on by other animals, this would support the conclusion.

Does this help clear things up? If not, please let me know!

[ebrickm2]

We're asked to strengthen the conclusion drawn in the argument.

The conclusion reached is that the drop in observed delta green ground beetles is not the result in an overall drop in delta beetle population.

The evidence for this is that the beetles remain motionless unless it rains, and in 1985 it was wet, while in 1989 it was dry.

The major assumption of this argument is that one cannot see the beetle, unless the beetle is in motion - perfectly expressed in answer choice (A).

(B) weakens the argument, maybe a little, because now the frogs are around water all the time, so who cares whether 1985 was wet year.
(C) is irrelevant. Why delta ground beetles move around is not important relative to whether or not we can see them.
(D) is irrelevant. It is not important whether or not these beetles are rare or common.
(E) is tempting because it brings in the idea that maybe the drop in population was due to being preyed on by another animal. However, this answer choice does not preclude the delta ground beetle from being preyed on, just from being the main diet of another animal. So had this choice, said that the beetle is not preyed on by other animals, this would support the conclusion.

Does this help clear things up? If not, please let me know!

I feel like the premise is irrelevant and distracting.

The conclusion is that population did not decline despite the fact that observed population declined.

How can one strengthen this?

You can say that the methodology for location the population was inefficient, the population is hard to locate, changes of condition, etc, etc.

I'm not sure what the premise really provides me other than confusion, halp!

[ManhattanPrepLSAT1]

So, why don't you feel like the premise is relevant?

We know that delta ground beetles remain motionless unless it rains. We are concluding about being able to see delta ground beetles. Why wouldn't the beetles being in motion be relevant to helping us see them?

[ebrickm2]

So, why don't you feel like the premise is relevant?

We know that delta ground beetles remain motionless unless it rains. We are concluding about being able to see delta ground beetles. Why wouldn't the beetles being in motion be relevant to helping us see them?

Okay, I see it now. The premise and conclusion for this question are tricksey. I think the ordering of argumentative elements tripped me up a bit.

We know that we saw more in 85 v 89 and the premise for the no decline argument is that when wet, which 85 as opposed to 89 was, that there was no decline in population b/c in wet times they move more.

I think I got it now, thanks!

[anjelica.grace]

Hi! Can someone further elaborate on why (E) is wrong?

I understand the above explanation that the AC just says they were not part of "a main portion of diet," which doesn't necessarily mean it wasn't preyed on but it still stands to reason that the lack of such a predator would support the idea of "no drop in the population"?

Help please!

Thank you!

[timmydoeslsat]

We want to strengthen the idea of a population decline not being the explanation for less beetles being spotted in 1989 than in 1985 at the same location.

The evidence we have tells us that 1985 was a wet year and 1989 was a dry year. We also know that beetles are more active in wet years. So we know that beetles will be more active in 1985 than in 1989, but what does that have to do with counting beetles in the same location?

Answer choice (A) gives us that link. It tells us that went beetles are not active, its almost impossible to see them, so thats why the number counted in 1989 was lower. The beetles were really there, its just the counter did not see them like the counter did in 1985 where the beetles were more active.

Answer choice (E) tells us that no predator relies on these beetles for their food supply. This fact would be true for 1985 and 1989. We want something that will distinguish these two years. And we can expect to use the evidence given to help with that, in particular the idea of wet and dry years.

[kpopstar123]

This argument is definitely about what caused the number discrepancy between year of 1989 and 1985.

The conclusion says that the weather was the cause, not the decline in population.

The stimulus says nothing about which is the better explanation for the observed phenomenon. Our job is to say that weather was the actual cause, not the decline in population.

A does the job.

[WaltGrace1983]

DGBs are more active in wet years than in dry years
+
1985: 38 DGBs observed in 2 hours
1989: 10 DGBs observed in 10 hours
+
1985: Wet year
1989: Dry year
-->
Difference in observation does not reflect a drop in population

We want to strengthen this conclusion by showing that the observations were NOT representative. I honestly didn't specifically know how we could do that but it would probably have something to do with distinguishing between a wet and dry year, as that is the premise that the argument is based on.

(A) If they are impossible to see (note: this word is connected to the observation) if not moving, then maybe the dryness of 1989 paired with the lack of movement in a dry year would help establish the conclusion. This looks good.

(B) So what? So the observations were probably done there.

(C) We don't care WHY they move. We only care about how all of this relates to observation.

(D) But they were found in 1985 so this is irrelevant.

(E) I like the way timmy put this: this doesn't distinguish between the two years. We would need something that shows why observations weren't representative. (E) could have been correct if it would have said something like, "The predators that rely on DGBs became extinct by 1987," this would probably strengthen by eliminating one reason why the population might not have declined.

[aaronwfrank]

DGBs are more active in wet years than in dry years
+
1985: 38 DGBs observed in 2 hours
1989: 10 DGBs observed in 10 hours
+
1985: Wet year
1989: Dry year
-->
Difference in observation does not reflect a drop in population

We want to strengthen this conclusion by showing that the observations were NOT representative. I honestly didn't specifically know how we could do that but it would probably have something to do with distinguishing between a wet and dry year, as that is the premise that the argument is based on.

(A) If they are impossible to see (note: this word is connected to the observation) if not moving, then maybe the dryness of 1989 paired with the lack of movement in a dry year would help establish the conclusion. This looks good.

(B) So what? So the observations were probably done there.

(C) We don't care WHY they move. We only care about how all of this relates to observation.

(D) But they were found in 1985 so this is irrelevant.

(E) I like the way timmy put this: this doesn't distinguish between the two years. We would need something that shows why observations weren't representative. (E) could have been correct if it would have said something like, "The predators that rely on DGBs became extinct by 1987," this would probably strengthen by eliminating one reason why the population might not have declined.

This is a really solid explanation. For anyone else still trying to square away E, if the predators became extinct in 1987, that would support the notion that the population hadn't changed. In fact, this might even imply that it went up by 1989.

As it stands, E doesn't really shore this up though. If some predators use it as a majority of food supply, this doesn't support the conclusion at all. In fact, if it were true, you could use it to make a case that the population HAD changed, especially if one of the predators lost a food source and began consuming more beetles.

[MiriamL498]

I think I see where I went wrong in my understanding of this question. When I read the stimulus I noted that the person had observed 38 beetles in 1985 and 10 in 1989. For some reason by the time I got to answer choice A, I had a hard time connecting the word "see" to the premise which talked about "observing." It only clicked for me after I saw one of the previous comments that had bolded the word see in answer choice A. Note to self: read more carefully! Okay, the one question that's still lingering in my head is whether or not E would be correct if we got rid of A as an answer choice. I think E does a good job at blocking a potential loophole in our argument. Based on my understanding of strengthening questions, the correct answer choice to a strengthen question DOES NOT have to 100% strengthen the argument. While I can see why E would not strengthen this argument 100%, I think that if our only other answer choices were B,C, and D then E could certainly be the accredited response. I would greatly appreciate any input.