LSAT 142 | Section 4 | Logical Reasoning: Q10

LR Question 10 Explanation

QUESTION TEXT: In 2005, paleontologist Mary Schweitzer made headlines…

QUESTION TYPE: Argument Evaluation

CONCLUSION: Schweitzer’s research helps show that dinosaurs are related to birds.

REASONING: Mary Schweitzer found that the collagen in Tyrannosaurus Rex is similar to that found in chickens.

ANALYSIS: This argument sounds very persuasive, but it hasn’t told us much.

Sure, T. Rex collagen is like chicken collagen. But is T. Rex collagen different from mammal collagen? Maybe all collagen is alike. In that case, the similarity between T. Rex and chickens proves nothing.

To evaluate the argument, we should know if related species are more likely to have similar collagen.

___________

1. Who cares how hard it was to find tissue. We found some. The argument is about whether this soft tissue lets us prove anything.
2. Not relevant. Any complicated claim will have some evidence against it.
   Also, the conclusion is not that T. Rex is related to birds. Rather, the conclusion is that Schweitzer’s evidence helps prove that dinosaurs and birds are related.
3. CORRECT. This is very relevant. If unrelated animals also tend to have identical collagen, then Schweitzer’s evidence is meaningless.

4. Who cares? Consider this hypothetical:

   • T. Rex is 95% related to most dinosaurs.
   • T. Rex is 90% related to chickens.
   • T. Rex is 89% related to one unusual species of dinosaur.
   • T. Rex is only 70% related to mammals.

   In this hypothetical T. Rex is more closely related to chickens than one unusual dinosaur species. But what does that prove? T. Rex is still more closely related to that dinosaur than to animals that are neither dinosaur nor bird (such as mammals).

5. It doesn’t matter what researchers thought beforehand. The results are all that matter.