PrepTest 154

Incorrect. This isn't relevant to the two phenomena we anticipated linking to explain the unusual data, temperature and population. We also can't extrapolate anything about the horse population from the size of their ancestors, any more than the sizes of ancient pre-human hominids could tell us anything about how many of us Homo sapiens should be wandering around today.

Incorrect. Just adds one more thing to a list of horse facts. As much as we all may enjoy a good horse fact, it's not connecting any dots. A correct Explain answer should connect two or more pieces of information in the stimulus in a way that allows us to explain something that was previously mysterious.

Incorrect. Species related to horses are out of scope. The question prompt specifically asks us to choose an answer that explains the horse population's boom and bust from 25,000 years ago. Modern zebras can't help with that.

Correct. Argument or Facts:
Facts

Question Type:
Paradox

Stimulus Summary:
Horses are grassland animals descended from forest animals. Historically, their population has gone through boom and bust cycles. The last peak was 25,000 years ago when the climate was cold, but the population rapidly declined after that.

Answer Anticipation:
As with every Explain question, the key to anticipating the correct answer is understanding what needs explaining. So, wherein lies the mystery? The most unusual thing described in the stimulus is the connection between the horse population and the global temperature. Horses aren't woolly mammoths that overheat in hot weather or anything like that, so why did they peak in a cold period and decline during warming? Expect the correct answer to provide a reason for linkage between the climate and horse numbers.

Answer Explanation:
Nice! This connects three pieces of information from the stimulus: horses' preferred habitat, their boom and bust population cycles, and how those might relate to global temperatures. If horses lose a significant portion of their grassland habitat when the planet warms, it makes sense that there are fewer horses during those times.

Key Takeaway:
For Paradox questions, don't be distracted by trap answer choices that just add another premise without linking two or more existing premises together to form an explanation. The correct answer choice will add new factual information, but it'll come in the form of connective tissue that makes previously unrelated items hang together in a way that implies an explanation.

Incorrect. Additional information about the climate doesn't help us if it doesn't help us connect the horse population to these cycles of climate change. We're not looking just for facts potentially related to the phenomenon in the stimulus, we're looking to explain a specific event.