Q13 - The size of northern fur seals provides a reliable ind

[Emily Madan]

PT68, S3, Q13 (Inference)

(E) is correct

From the paragraph, we get the following facts. First, northern fur seal size reliably indicates population size. Second, one 800-year period studied showed no significant variation in body size. Before evaluating the answer choices, take a moment to evaluate if you can make any inferences. However, often the inference is not obvious, and we have to evaluate the answer choices without a clear prediction.

(A) This one can be tempting if you don’t read it closely. However, this answer choice is not about the seal population, but rather about the seal hunting practices. We know nothing about seal hunting practices, so eliminate this choice.

(B) This answer directly contradicts one of the facts stated in the paragraph. Eliminate it.

(C) This answer may or may not be true, but we have no information about any time period outside the 800-year period studied. Eliminate it.

(D) This answer speaks to the intent of the Native peoples. We have no information about their intent. Eliminate it.

(E) This answer simply says that the hunting did not significantly decrease the population size. Let’s evaluate this based on what we know. Size is an indicator of population, and there was no significant variation in size over this period. We can therefore correctly infer that there was no significant variation in population. This is the correct answer.

[halflate37s]

Another point about answer A:

The stimulus says the study showed the average seal body size did not change very much. Which means that across different groups of Native North Americans, hunting practices could actually vary greatly.

Scenario 1
If group 1 hunts 150 seals a year in a region containing seal population 1 and group 2 hunts 50 seals per year in a region containing seal population 2, over time leading to the average body size in population 1 to be 300lbs and the average body size in population 2 to be 100lbs, the total average body size is 200 lbs.

Scenario 2
Given the same average body size of 200 lbs, both groups could hunt the same number of seals per year and the body size could start out and remain around 200 lbs over all that time.

There is not enough information in the stimulus to exclude the first scenario, so there is no support for the second scenario, which is described answer A.