LSAT Question Explanation
PT 119, Section 3, Question 18
Identify the RoleArgument structure
A very maladaptive trait is unlikely to persist in an animal population for very long.
Because of genetic variation, there will be animals without the maladaptive trait. And since they don't have the harmful trait they will be more successful in surviving and reproducing, and eventually the harmful trait will disappear from the gene pool.
Explanation
This argument presents the conclusion in the beginning of the first sentence, and everything that follows is the biological explanation (evidence) as to why a maladaptive trait won't persist for long.
The claim in the question stem is just one of the pieces of evidence that's introduced in the argument. There's nothing that supports it, the author just states that claim to be true, so it's a premise.
Answer choices
No, the claim in the question stem aligns with the rest of the argument, indicating why maladaptive traits won't persist. Nothing discredits it.
There's no support for the claim in the question stem. It's not a conclusion at all.
Yes. The claim in the question is a premise that supports the argument.
Similar to (A), nothing else in the argument undermines or contradicts the claim we're concerned with.
No, there's no support for the claim in the question stem