Logical reasoning PrepTest 150 · Section 3 · Question 15

Incorrect. C agrees with this statement. O might seem to, but she only states that the oldest known remains are that old, and the statistical model is speculation. She could believe that the first primates were from a little earlier than 55m years, or even older than that, just without strong supporting evidence.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Point at Issue

Stimulus Summary:
C: Using comparative statistics (which we assume is a thing), our model estimates the first primate came about 81.5m years ago.

O: The oldest primate bones are 55m years old, so your estimate is speculation.

Answer Anticipation:
C doesn't address any of the issues in O's argument, but O directly mentions that C's estimate is speculation, so we should focus on that. The only idea that overlaps between the two is whether the conclusion of the statistical model is realistic, so that will probably be the idea discussed in the correct answer.

Answer Explanation:
C agrees with this, since it's his statistical model. O, however, specifically calls the conclusion "sheer speculation," showing us that she questions the accuracy of that model. This answer is correct.

Key Takeaway:
When a speaker disagrees with another, make sure you understand the extent of that disagreement. Does the second speaker disagree with the conclusion, or just believe that it is as yet unproven? The difference matters greatly on the LSAT.

Incorrect. Neither speaker directly addresses this. One might say O agrees with this since she uses the lack of fossils as providing evidence that primates didn't live before 55m years ago, but that would be an incorrect summary of her view. She doesn't think C is necessarily wrong, just that his model is speculative compared to the fossil remains.

Incorrect. C doesn't speak to the age of fossils, so this answer can't be a point at issue.

Incorrect. There's evidence that C disagrees with this, since he uses a statistical model to date the earliest primates instead of testing the age of the fossils. However, while O does bring up the earliest known fossils, she doesn't indicate whether she believes these to be of the first primate. Since she states that C's conclusion is speculative, and not wrong, she's only committed to believing that his argument lacks evidence, and not that the current evidence disproves his claims.