#17 - Since mosquito larvae are aquatic, outbreaks of

[Adam Tyson]

Absolutely that, lsatstudying11, but also that there is no connection given between plant growth and mosquitos. Do they breed more when there are more plants, or are they harmed by more plants, or do plants have no effect on them? Without knowing something about the relationship between plant growth and mosquitos (and mosquito-borne diseases), this answer just does nothing to help make sense of the situation.

[LSAT4Life]

Can you explain why (D) is incorrect? I thought that there is a possibility that if there a greater variety of mosquitos then maybe some species aren't affected by the drought.

I see that the stimulus is saying "mosquito larvae" are aquatic so maybe it's implying that mosquito larvae are ALL aquatic across species?

[atierney]

Hi LSAT4Life,

D here doesn't explain why the outbreak of disease is worse in wetland areas after a drought. So, even if there are a greater variety of mosquitos, that fact alone, while potentially explaining the fact that outbreaks occur at all in the presence of a drought (given the ubiquity of potentially unique species not breeding in the water), it doesn't explain why a greater number of outbreaks would indeed occur in this area after a drought. I believe you are correct in your reading of the first line of the stimulus, and thus, we should assume that all mosquito larvae are aquatic. If so, then D doesn't really explain anything, since the drought would produce conditions adverse to all species of mosquito larvae. Regardless, it certainly doesn't show how the diversity of species leads to the fact that there would be a greater rate of disease outbreak after a drought, which presumably requires a greater rate of mosquitoes breeding in drought conditions. Because this key fact is not explained in D, D is not the correct answer.

However, C explains how we could come to expect greater disease outbreak after a drought, mainly because there are less mosquito larvae surviving in non-drought conditions due to the presence of aquatic insects that prey upon them. As an aside, I must say, in which case, sign me up for a home by the wetlands!


Let me know if you have further questions on this.

[hope]

Responding to Kelsey's post:

The argument that "Fewer predators = more larvae = more mosquitoes = more outbreaks" requires the assumption that during times of drought the only insect that are fewer in number is the predatory insect. Why couldn't the mosquito larvae also be fewer in number since they are aquatic? Isn't water the perfect breeding environment for them?

And if my theory is correct, why then would there be a worse outbreak after the drought with fewer existing larvae?

To me, for C to be correct (and of course I accept that it is) one would have to assume (which Powerscore tells us never to make unwarranted assumptions) one would have to assume that larvae, unlike the predatory insects, increase (and not decrease) during the drought.

This is the reason that I did not choose C after considering it. Thank you Kelsey if you are able to respond to my post.

[hope]

Also, I should have said more specifically that C carries the assumption that mosquito larvae's reproduction capacity is the SAME during time of drought as it is during wetter times. If not the same, even greater reproductive capacity for greater outbreaks to occur after drought. Thank you.

[Robert Carroll]

hope,

There is no need for an assumption that predators are the only species less common, and the assumption that mosquito larvae would be less common in drought times is essential to the paradox of the stimulus. It seems common sense that mosquito larvae, being aquatic, would not do well in times of drought. Yet outbreaks are worse during droughts. That's the paradox! So we need some explanation that shows that, despite what seems obvious, mosquito larvae actually aren't harmed as much by droughts as we think - in fact, they seemed helped by droughts.

We don't need to assume mosquito larvae increase during droughts. If predators are less common during droughts, as answer choice (C) gives us, then there are two factors affecting outbreaks during droughts - the larvae-reducing effect of the drought's effect on the habitat, plus the larvae-increasing effect on predators. Answer choice (C) is just giving a positive for the mosquitos, additional to the obvious negative effect of a drought.

The reproductive capacity does not have to be the same during a drought - in fact, it could well be reduced! The reduced predator population, though, will counteract that - mosquitos reproducing less well can actually be fine for their populations if the predators are doing even worse. That's all an answer choice has to do for a Resolve question - provide some solution to the paradox. Droughts are good and bad for mosquitos, not just bad like you'd think, so maybe the good outweighs the bad. That's all.

Robert Carroll

[jdleggett]

But if a draught causes a decrease in mosquito predators, wouldn't it also decrease mosquitos??

[Adam Tyson]

Not necessarily, jdleggett, and in fact one would normally expect that a decrease in predators would result in an increase in the prey species. Predators tend to keep a prey population in check. On the LSAT, a common sort of problem in Resolve the Paradox questions involves this relationship, such as a prey species flourishing after a predator is introduced into their environment, which is the opposite of typical expectations. The resolution usually involves the predator doing something beneficial to the prey, like crowding out a competitor or strengthening the herd by preying only on the sick and weak.

It's easier to thrive when nothing is trying to eat you!