By examining fossilized beetles a research team has produced the most

Let's break down the "procedure of the researchers" as described in the passage:

• First, they found fossils of species of beetles that still exist, and determined the date of those fossils.
• Then they narrowed their scope to cases in which "individuals of several species found in the same place were found to date to the same period."
• Then, they used the "known temperature tolerances" of the species (which they know because the species exist in the current day) to determine what the maximum summer temperature could have been at the time when the fossilized beetles lived.

So, the researchers applied information about existing beetle species to fossils of the same species to produce "the most detailed description of temperatures in Britain over the past 22,000 years."

To answer the question, we need to find an assumption made by the researchers in this procedure. Let's look at the answer choices:

The passage gives us no information about how well the beetles tolerate either cold or warm weather, and the researchers certainly did not have to assume that they tolerated one better than the other. (A) is out.


The researchers only focused on cases in which "individuals of several species found in the same place were found to date to the same period." This is the opposite of the information in answer choice (B), so (B) is not an assumption made by the researchers.


The passage does tell us that dating beetles has produced "the most detailed description of temperatures in Britain over the past 22,000 years." But do the researchers have to assume that the process of dating is more accurate for beetles than other organisms?

No, they do not. The procedure used by the researchers would not be impacted in any way if all organisms could be accurately dated -- it is only necessary that the beetles can be accurately dated. (C) is out.


It really doesn't make sense that the highest actual temperature would be the average of the highest tolerated temperatures for the species that existed in that time and place.

Take this example: The fossils of two existing species are found in one location and dated to the same time period. One species can tolerate temperatures up to 100 degrees, and the other can only tolerate temperatures up to 60 degrees. Using the information in answer choice (D), the highest actual temperature would have to be 80 degrees -- which is impossible, because then the second species would not have been able to exist in that time period. (D) is out.

Now look at (E):

The researchers use the temperature tolerances of beetles that exist today to determine what the maximum temperatures could have been over the past 22,000 years. So, the researchers must assume that the temperature tolerances of these beetle species have not changed significantly over this time period. (E) is the correct answer.

I hope that helps!