LSAT 144 | Section 3 | Logical Reasoning: Q12

LR Question 12 Explanation

QUESTION TEXT: In a study of tropical forests it was found that while…

QUESTION TYPE: Paradox

PARADOX:

1. The most common species reproduce the most, and the rare trees live longer.
2. This is true no matter which species is common and which is rare.

ANALYSIS: Your first task on paradox questions is to understand the paradox. Let’s imagine that there are only two trees in forests: spruces, and elms.

• In one forest, spruces are most common, and elms live longest.
• In another forest, elms are most common, and spruces live longest.

So it’s not some feature of each tree species that causes them to live longer. It’s the fact that trees are rare that seems to cause them to live longer. The species that reproduces best within a forest is also the shortest lived. That seems odd, and it’s what you have to explain.

___________

1. This explains why one species is more common, but it doesn’t explain why the rare species lives longer.
2. This explains nothing. It doesn’t tell us why trees live to be old in the first place.
3. Good, this shows the scientists were smart enough not to introduce an uncontrolled variable into their experiments. But this doesn’t explain anything, it just means that the experiments were well done.
4. This shows that it is useful for the rare species to survive. But that doesn’t explain why they survive. Plenty of useful things never happen.
5. CORRECT. If there’s more competition, then we can expect some trees of the more common species not to have enough resources, and to die. The rare species are living a life of luxury, as there’s little competition for resources. Thus they live longer.