LSAT 115 | Section 2 | Logical Reasoning: Q16

LR Question 16 Explanation

QUESTION TEXT: Biologists agree that human beings evolved from a fish…

QUESTION TYPE: Role in Argument

CONCLUSION: Hoyt claims that humans are descended from lungfish. Grover claims we are descended from coelacanths.

REASONING: Frogs are related to the fish from which we are descended.

Hoyt found a similarity in the mitochondria of lungfish and frogs.

Grover does not believe mitochondria can reliably show a link. She points instead to a hemoglobin match between tadpoles and coelacanths.

ANALYSIS: After reading this question and all of the answer choices, I realize I hadn’t understood a thing. So I read it again slowly, and immediately understood. Don’t be afraid of taking the time you need to understand a question: it will speed you up overall.

___________

1. Actually, it provides some support for the idea that we are descended from lungfish.
2. It also provides some evidence that we are descended from coelacanths.
3. Neither scientist believes this is an either/or situation. The stimulus does not exclude a third possibility.
4. CORRECT. Yes. Both scientists agree with this assumption, and use it to craft their arguments.
5. I say frog, you say hemoglobin? The info about frogs, by itself, doesn’t imply that a match means anything at all. The scientists are the ones who each claim that those matches prove common ancestry.

Recap: The question begins with “Biologists agree that human beings evolved from a fish”. It is a Role in Argument question. Learn more about LSAT Role questions in our guide to LSAT Logical Reasoning question types.