Self-study
Archaeologist: A skeleton of a North American mastodon that became extinct at the peak of the Ice Age was recently discovered. ██ ████████ █ ██████████ ██████████ ██████████ ██ ███ █████ ██ ████ ████ ██ ███████ ███████ ██ █████ ████████ █████ █████ █████████ ███ ███ ██████ ██ █████ ███████ █████ ███████ ██████ ███ ████ ██ ███ ███ ████ ███ █████ ████████ ████████ ██ █████ ███████ ████████ ████ ████ █ ████ ███████ ████ ██ ████████
Summarize Argument: Phenomenon-Hypothesis
The archaeologist concludes the first Eurasian settlers in North America were not the closest. Why? Because a projectile found in a mastodon is dissimilar from any in the closest part of Eurasia, and the first Eurasians in North America settled shortly before the North American mastodon went extinct.
Notable Assumptions
The archaeologist assumes the projectile could not have been made by people from the closest part of Eurasia, either because it resembles a projectile from elsewhere in Eurasia or because people from the closest part of Eurasia were less likely to develop a new projectile for some other reason. She also assumes that only the first settlers to North America from Eurasia could have made the projectile, and that it penetrated the mastodon while it was alive.
20.
Which one of the following, ██ █████ ████ █████████ ███████ ███ ███████████████ █████████
a
The projectile found ██ ███ ████████ ████ ███ ████████ ███ ████ ████ ████ ██ ███████ ██████ ██ ██████ ███ ███ ████
This eliminates the distinction between the closest part of Eurasia and the rest of Eurasia. If the projectile doesn’t resemble any from Eurasia, there’s no reason to assume its makers came from farther in Eurasia.
b
The people who ████████ ███ ████████ ████ ███████ ██ █████ ███████ ████████ ███████ ██████████ ███ ███ ████
This doesn’t mean those people left the area closest to North America. It’s possible people in Eurasia maintained well-defined geographic boundaries despite living nomadic lifestyles.
c
The skeleton of █ ████ ████ ███ ████ █████ ███ ████ ██ ███ ████████ ████████ ████████ █ ███████ ███████████
The species of prey is not relevant to the argument. The subsequent extinction of the mastodon implies the settlers who killed it were some of the early settlers, and the existence of a bear with the same projectile doesn’t change that fact.
d
Other North American █████████ ████ ███ ████ ██ ███ ███ ███ ███ ███████ ██ ████ ████ ███ ████ ████ █████ ██ ████ ███████ █████ ██ ████████
This provides another reason to believe the archaeologist’s conclusion, but does not address her argument. The presence of these other artifacts does not challenge any assumption made by the archaeologist to draw her conclusion.
e
Climatic conditions in █████ ███████ ████ ██████ ███ ███ ███ ████ ████ █████████ ██ █████ ██████████ ████ ████ █████ ██ ███ ████ ██ ███████ ███████ ██ █████ ███████ ██ ████ █████
This draws no distinction between the parts of Eurasia closer to and farther from North America that calls into question the archaeologist’s conclusion. It’s possible the parts of Eurasia farther from North America were equally inhospitable.