LSAT 111 | Section 1 | Logical Reasoning: Q17

LR Question 17 Explanation

QUESTION TEXT: The reasoning in the argument is most…

QUESTION TYPE: Flawed Reasoning

CONCLUSION: The Antarctic ice sheet must have temporarily melted three million years ago.

REASONING: Some fossils were found in Antarctica that previously were only found on the sea floor. The fossils were three million years old.

ANALYSIS: This is a bad argument. It’s possible that the ice melted. Or it’s possible that the fossils were from an animal that could live both on land and in the ocean (e.g. maybe some kind of bird.)
The fossils had only been found on the ocean floor, but that doesn’t mean they couldn’t be found anywhere else.

So while melting ice is a possible explanation, it isn’t the only possible explanation.

___________

1. The argument doesn’t mention public opinion or popular belief as to whether Antarctica melted. We have no idea what people think.
2. The argument did not claim that volcanic activity and climactic warming could not have happened together. 
3. The argument didn’t claim to know the cause for certain. The last sentence shows that the author isn’t sure of the cause. The melting could have been due to warming or volcanoes. The author’s only conclusion is that the ice sheet did melt.
4. The claim is pretty specific: there was temporary melting, in Antarctica, three million years ago.
5. CORRECT. The inconsistency is that fossils that were previously found only in the ocean were found on land. The resolution (explanation) given in the stimulus is that Antarctica must have been underwater once. But it could also be true that the animal that left the fossils lived both on land and on water.