LSAT 107 | Section 3 | Logical Reasoning: Q22

LR Question 22 Explanation

QUESTION TEXT: Biologist: Some speculate that the unusually high…

QUESTION TYPE: Most Strongly Supported

FACTS:

1. Only the reproductive success of a trait can determine how common it is in a population.
2. Goats on islands tend to be smaller.

ANALYSIS: There must be some reproductive success for small goats that live on islands. That’s the only way to explain why that trait (smallness) is common in those populations (according to the biologist.)

So no other explanations work, including the genetic diversity explanation.

___________

1. The biologist disagrees with this answer choice in the second sentence. He clearly says that only reproductive success can influence how common a trait is.
2. Actually, the biologist would say that the frequency of small goats almost certainly means they do have a reproductive advantage.
3. This is completely false: large goats are rare on islands.
4. CORRECT. The biologist clearly says that only reproductive success influences how common genes are. All other explanations are wrong.
5. The biologist says that the diverse gene pool explanation is wrong. So we have no idea how to achieve a diverse gene pool.

Recap: The question begins with “Biologist: Some speculate that the unusually high”. It is a Most Strongly Supported question. Learn more about LSAT MSS questions in our guide to LSAT Logical Reasoning question types.