PT119.S1.P3.Q17 > Analytics

passage 3

The pronghorn, an antelope-like mammal that lives on the western plains of North America, is the continent's fastest land animal, capable of running 90 kilometers per hour and of doing so for several kilometers. ███

Intro Topic · Pronghorn

███████ ██ █████ ████████ ████████ ██ ██████ ████ ██████ ██ █████ ██ █████ ██████████ ████ ███ ██████████ ██████████ ███ ███ █████████ █████████ ███ ███████ ████████ ███

Puzzling Phenomenon · Pronghorns' speed

Why are they faster than they need to be to escape any predator?

Biologist: Explanation · Speed was adapted for extinct predators

Others: SKEPTICAL · Others skeptical of relict behavior hypothesis

Relict behavior defined as behavior adapted to extinct conditions, e.g., extinct predators.

Others: Elaboration · Skeptical of hypothesis because difficult to test

Extinct conditions (e.g., predators) means no longer exist, so how can you test?

███ ███████████ ████████████ █████████ █████ ████████ ████ ████████ ██████ ████████ ███████████

Support Biologist · Some evidence supporting general relict behavior hypothesis

But what about for pronghorns, specifically?

Support Biologist · Lots of evidence for pronghorn relict behavior hypothesis

███ ████████ █████████████████ ████ █████ ███████ ██████████████ ██ ██████ █████ ██████ ████ ████ ██ █████ ███ █████████ ███ ██████████ ███ ███████ ██ ███ ██████████ ██████ █████ ████████ ███ ███ ████ ██████ ██ ████████████ ███ █████████ ███████████ ███ █████ ████ █████ ██████████ ████ ███████ ██ ████ ████ ███████████ ██████████ ███ ████ ████ ███████ ██ ████ ████ ████████ █████ ███████ ████████ ███████ ██ ██ ███████ ██████████ ██ ███████ ████████ ██████████ ██ █████ ███ █████████ ████ ████ █████████ ██ █████████ ███████████ █████ ██████ ██████████ ██ ██████ █████ █████ ██ █████ ████████ ██████████ █████ ████ █████████ ██████ ███████████ ███ ████████ ████████ ███ ██████ █████ ████ ██████████ █████████ ████ █████ ██ ███████ ███ ███████

Examples · Roam in herds, choose faster mates

Both behaviors once conferred evolutionary advantage but no longer do. Yet we still observe this relict behavior.

██████ █████████ ██████ ██ █████ ██ █████ ███████ ██ █████ ██████████ ███ ███████ ████████████ ██ ████ █ ███████ ███

Support Biologist · Relict behavior in other animals

███ ████████ ███ █████ ███████ ██████ ████████ ██ ███████████ ████ █████████ ██ ███████████ ████ ████ ████ ████ ████ ██ █ █████████ █████████ ███ ████████ ██ ███ ██████ ████ █████████ ████ ████████ █████ ███████████ ████ ███████████ ███████ ██ █████████████ ███████████ █████████ ████████ ███ █████ ███ ████████ ██████ ██ ████ ███ ███████ █████ █████ ████ ██████ █████████ ████ ███████████ ████ ████ ████ ████ ████ ██████ ███ ██████ ██ ███████ █████ █████ ███████ █████████ █████████████ ██████████ █████████████ ███████████████ ████████ ██ ███ ████████ ██ ███ ██████ ███

Examples · Stickleback, ground squirrels

Both exhibit relict behavior: they avoid extinct predators.

Elaboration · Relict behavior can disappear over time

Arctic squirrel lost extinct predator avoidance behavior after 3m years.

Passage Style

Phenomenon-hypothesis (RC)

Single position

Analysis by Kevin_Lin

17.

Based on the passage, the ████ ██████████ ██████████ ███████ ████████ ██ ███ ██████ ██████████ ████ ███████ ██████ ██ █████ ███ ██ ███ ██████████

Question Type

Purpose in context (of word, phrase, or idea)

Structure

Testing explanations based on relict behaviors is difficult because of the “extinction of a principal component.” Earlier, we’re told that a relict behavior is a behavior that exists due to “long-extinct environmental conditions.” What’s the “principal component” that is extinct, then? The environmental conditions that no longer exist, but that once allegedly caused evolutionary adaptations.

behavior that persists ████ ██████ ███ ██████████ ████ ████████ ███ ████████████ ███████ ███ ███████

the original organism █████ ████████████ ████████ ██ █████ ████████████ ██ ██████ ████████

As explained below the question stem, the “principal component” refers to the environmental conditions that are extinct, but that caused evolutionary adaptation of the behavior that we see today. Nothing in the passage suggests that the phrase refers to the original animal from which the animal whose relict behavior we are examining descended. (For example, the evolutionary ancestor of the pronghorn. Do biologists believe it’s difficult to test the relict behavior hypothesis for the pronghorn because the ancestor of the pronghorn no longer exists? No.)

the pronghorn's ability ██ ███ ██ ██████████ ███ ████ ████ ████ █████████

the environmental conditions ██ ████████ ██ █████ ██████ █████████ ███ ███████ ██ ████ █████████

an original behavior ██ ██ ██████ ██ █████ ███████ ███████████ █████████ ███ ███████ ██ ██ █████████████

PrepTest 119 - Section 1 - Passage 3 - Question 17

Difficulty

Analysis

Answer Popularity

Question history

Confirm action