LR Question 19 Explanation
QUESTION TEXT: A recent study examined the daytime and nighttime…
QUESTION TYPE: Paradox
PARADOX: Deciduous forest lemurs have more of a winter nocturnal increase than rain forest lemurs do.
In deciduous forests, trees lose their leaves in winter. In rainforests, trees keep their leaves.
ANALYSIS: I’ve called this question “paradox” for consistency, but really there’s no paradox here. There’s just a lot of information – your task is reduce it to the essential bits. I summarized those above.
The right answer should describe a difference between those two forests. Note that in the setup, the only difference is that in winter, the deciduous lemurs won’t have leaves.
___________
- This answer shows a similarity between both populations. So it can’t help explain a difference.
- CORRECT. This might seem irrelevant. But remember that deciduous forests lose their leaves in winter. So a high flying bird will be able to see lemurs more easily during the day in a winter deciduous forest, due to lack of leaf cover.
At night, of course, it’s too dark to use eyesight to see lemurs. So presumably the birds sleep, and lemurs come out at night in winter deciduous forests because it’s the only safe time.
This answer requires a bit of outside knowledge, which you’re allowed to do when everyone would agree with it. “Darkness and leaves reduce visibility” is a warranted assumption. - Same as A. This provides a similarity between both forests, so it can’t explain a difference.
- The population size doesn’t matter. We judge whether a population is nocturnal based on what the whole population does. A forest with ten lemurs could be more nocturnal than a forest with 10,000, if those ten lemurs stayed up all night.
- You might have picked this because you thought leaves are plants. But this doesn’t explain anything. Obviously, lemurs in deciduous forests don’t starve – they just become nocturnal. Having a plant/insect diet or instead only a plant diet doesn’t tell you anything about whether a species is nocturnal or not.
More Resources for Paradox Questions
- Intro Course lesson: This intro course lesson covers Paradox questions.
- Mastery Seminar lesson: This LR Mastery seminar lesson covers paradox questions.
Being as they are described as tree-dwelling, I thought B would be opposite of what I was looking for. Lemurs without a canopy would want to sleep at night because the predators could spot them more easily during the day and I took tree-dwelling to mean that they sleep in trees and those birds could just pluck them out so would make more sense for them to be opposite of nocturnal.
I chose E and I’m struggling to see why this is wrong (this never happens in the LSAT)
My thinking was thus: E tells us that the lemur population in the rain forest eats plants (and also insects) and so do the ones in the deciduous forest. Fortunately for the lemur population in the rain forest, they wide access to plants year round “tree canopy cover” whereas the poor plant eating lemur population doesn’t have the same bounty, and thus have to resort to additional hunting. Perhaps they hunt more overall, perhaps they smartly recognize that their predators are out in far smaller amounts.
I don’t see that that thinking requires much more of a leap than B does. If the assumption is that the lemurs literally live in the trees (meaning the year round canopy offers protection) then why not also assume that insects are drawn to that same living space, meaning they don’t have to go hunting as much.
I’m a little flabbergasted here.
(E) is tempting because it suggests that there’s a significant difference between the lemur populations, and many students then select it because perhaps that difference would explain the difference in nocturnal patterns. But, there’s no connection (at least in the stimulus) between being a herbivore and being nocturnal. Even if we assume, as you’ve done in your analysis, that the deciduous tree lemur population would need to hunt more because of the lack of canopy coverage, how does that tie into more night-time activity? Why couldn’t they just forage more by day? We can’t assume that there are fewer predators by night and they come out then for that reason. It’s too much of a stretch beyond what we’re given in the answer choice and stimulus.
If (A) is invalid for the reason you gave, then (B) would also have to be invalid since it explicitly describes a similarity between the two populations. So it’s at least incomplete. Maybe it’s more accurate to say that (A) simply doesn’t tell us why one lemur population would have to be more active at night, let alone why the one with less leaf cover would have to be more active at night.
Not so. While B *seems* like a similarity, we know based on common sense it’s actually describing a difference: it’s easier to see lemurs in daylight if there are no leaves.
But that could also be said for A because maybe daylight is more pronounced (ie longer) as seen by the lemurs when there is no cover from leaves… Thus in the more limited time available to those decidious forest lemurs, they are more active because they may have to be.
I can see why B is right, but similar reasons show that A can be right too IMO.
In the real world I really like your thinking! On the LSAT, though, there’s no valid reason to think that daylight is actually more pronounced in the decidous forests. That’s a big dangerous leap to make! For example, it could be that since decidious forests tend to be at higher latitudes they receive even less daylight during the winter than rainforests do – we just don’t know.
-Reply from LSAT Tutor, Morgan Barrett