Q15 - Carrillo: Using the number of existing primate species

[ohthatpatrick]

Question Type:
ID the Disagreement

Stimulus Breakdown:
C: Our model (based on number of existing primates and genetic diversity of existing/extinct primates) says earliest primate was 81.5 million years ago.
O: Based on fossils, earliest primate was 55 million years ago, so your model's estimate is sheer speculation.

Answer Anticipation:
Person 1 only makes one claim, so here it's obivous that person 2 will disagree with that claim. Person 1 claims that his model STRONGLY SUPPORTS the idea that first primate was 80 million years ago. Person 2 claims that the model is MERELY SPECULATING that first primate was 80 million years ago.

Since this disagreement is so explicit, LSAT is more likely to test the underlying basis for their difference in conclusion. They each mention different types of evidence. It appears C trusts stats / numbers / genetic diversity, while O seems to trust fossil evidence much more. So the correct answer will likely be about whether strong conclusions can be derived from non-fossil evidence.

Correct Answer:
B

Answer Choice Analysis:
(A) O doesn't make any prediction about how long primates have been around. She's only saying that C's estimate seems speculative.

(B) YES, this seems to work. This gets at the difference between "our model strongly supports" vs. "your estimate is sheer speculation".

(C) This could work if said "available fossils are representative of the AGE of primate species that have existed".

(D) We have no reason to think C disagrees with the dating of those fossils.

(E) This is an extreme idea. Neither person has committed to believing this. O comes closer, but even she said "the oldest fossil SO FAR".

Takeaway/Pattern: The answer choice language here was drifting from any of the explicit claims, but since C only made one claim, we knew that O had to be disagreeing my saying "your statistical model DOES NOT strongly support the conclusion that first primates were 80 million years ago". (B) is definitely the closest in meaning to that. The "Disagree"version of (B) sounds like "your statistical model IS NOT a reliable way of determining first primate", which sounds a lot like "your estimate is sheer speculation".

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