LSAT 151 | Section 4 | Logical Reasoning: Q21

LR Question 21 Explanation

QUESTION TEXT: Evolution does not always optimize survival of an…

QUESTION TYPE: Method of Reasoning

CONCLUSION: Evolution doesn’t always maximize survival of species.

REASONING: Moose antlers help them win mating battles with other males. But really large antlers make moose more vulnerable to predators. Moose would collectively be better off with smaller antlers.

ANALYSIS: Basically, evolution has pushed moose into an arms race. Collectively, everyone would be better off with no arms race. Individually, a moose is better off winning the arms race. So large antlers prevail.

The technique used in this argument was a detailed example used to disprove the claim that evolution always optimizes for an organism’s survival.

___________

1. I initially picked this. The moose are the example. And in my explanation for this answer, I wrote “The competing claim is….”
    
   Oops! The answer does not say “competing claim”. It says competing argument.
    
   It is very easy on the LSAT to read what you want to read. This answer would have been right had it said claim, but it didn’t. And there was no competing argument.
    
   This shows why you must at least skim all the answers on logical reasoning, even though you’re 100% confident an early answer is right. I picked A, but got to C and thought “Oh crap, this sounds pretty good too”. When that happens, you have to totally reassess each answer in isolation. You cannot start from the premise “A is the best, but I like C too”. Starting over made me realize I had read A improperly.
2. There’s no analogy. An analogy involves two situations.
    
   Example of analogy: Arms races are bad, and we should not get into arms races with the Chinese and the Russians. Let me give you an analogy from the animal kingdom to prove my point: moose have arms races too. They….
3. CORRECT. The general claim is “evolution always optimizes for survival”. The moose are an example that undermines this claim, which makes them a counterexample.
4. This is a totally different style of argument. And in the argument, the only example was the author’s own example. The author didn’t dispute the relevance of their own example!
    
   Example of argument: You say that reindeer should have smaller antlers, because moose antlers make moose vulnerable to predators. But, moose live in forest, whereas reindeer live in the tundra, where no trees catch on antlers. So, moose are not relevant to evaluating reindeer survival.
5. It is very rare for a claim to be self contradictory. Such a claim will be something like “My pen is blue because it is red”.
    
   The author did contradict the claim that evolution always optimizes for survival. But they did so with outside evidence. The claim itself is not self contradictory.