LSAT 101 | Section 4 | Reading Comprehension: Q15

RC Question 15 Explanation

DISCUSSION: The first paragraph presents a question: why are there more species towards the equator?

The rest of the passage presents theories that try to answer this question. The author thinks that the final theory is most likely correct.

That theory explains why the rate of species growth may have been higher in the tropics.

___________

1. The author never said which of the four theories is most accepted by other scientists. They personally favor the fourth theory.
2. This is quite incomplete. It doesn’t mention the problem to be solved: why do the tropics have more species? Not all the explanations say that the speciation rate is higher in the tropics.
3. CORRECT. This covers the problem (why are there more species in the tropics?), the failed solutions, and the solution accepted by the author.
4. All the theories explain past differences. None of them predict the future. Now that humans exist, it’s hard to predict what will happen to Earth’s species.
5. This is usually good advice for judging a scientific theory, but the passage never mentions this. Some of the theories are untested, but they might be testable.