LSAT Explanation PT 40, S1, Q11: According to the theory of continental

LSAT Question Stem

Which one of the following discoveries, if it were made, would most support the above hypothesis about South America and Africa? 

Logical Reasoning Question Type

This is a Strengthen question. 

Correct Answer

The correct answer to this question is A. 

LSAT Question Complete Explanation

First, let's break down the argument in the passage. The passage presents a hypothesis called the theory of continental drift, which states that in prehistoric times, many of today's separate continents were part of a single huge landmass. The passage then provides an example, hypothesizing that South America was once joined on its east coast with what is now the west coast of Africa. The structure of the argument is as follows:

Premise: The theory of continental drift states that separate continents were once part of a single landmass.

Example: South America and Africa were once joined.

Conclusion: The continents broke apart due to plate movement, and ocean water filled the newly created chasms.

To make this concept more accessible, consider a jigsaw puzzle. Imagine that the puzzle pieces represent continents, and they were once all connected to form a single picture. Over time, the pieces moved apart, creating gaps between them, just like how the continents drifted apart and created oceans.

An "Evaluate" question for this argument could be: "Is there any geological evidence that supports the connection between South America and Africa?"

Now let's discuss the question type and answer choices. The question is asking us to strengthen the hypothesis about South America and Africa. We need to find evidence that supports the idea that these two continents were once connected.

Answer Choice A: This choice strengthens the hypothesis by providing geological evidence that supports the connection between South America and Africa. The presence of a rare rock type along both coasts suggests that the two continents were once part of the same landmass. This is the correct answer.

Answer Choice B: While genetic similarities between people in Brazil and western Africa are interesting, they do not provide direct evidence of a connection between the landmasses. This answer choice is not sufficient to strengthen the hypothesis.

Answer Choice C: Similar climates between western Africa and the east coast of South America could be due to other factors, such as their proximity to the equator. This does not provide direct evidence that the continents were once connected and does not strengthen the hypothesis.

Answer Choice D: Linguistic similarities between tribes in eastern South America and western Africa do not necessarily indicate that the continents were connected. Language can spread through human migration and cultural exchange, so this answer choice does not strengthen the hypothesis.

Answer Choice E: The resemblance of plant species in western Africa and South America could be due to similar climates or human propagation efforts. This does not provide direct evidence that the continents were once connected and does not strengthen the hypothesis.

In conclusion, the correct answer choice is A, as it provides geological evidence that supports the connection between South America and Africa, thus strengthening the hypothesis presented in the passage.