Self-study
The size of northern fur seals provides a reliable indication of their population levels—the smaller the average body size of seals in a population, the larger the population. ██████████████ ███████ ████ ███████ ████████ ██ ████████ ██████ ████ ███ █████ ████ ██████ ███ ████ ██ ██████ ███████ ██ █████ ███████ ███ █████ ████ ███ ███████ ████ ████ ██ ███ █████ ███ ███ ████ ██████████████
Summary
The average body size of a certain seal type reveals information about their population levels. Smaller average body sizes in seal populations indicate a larger population. Fossils show that during an 800-year period when seals were hunted by Native Americans, the average body size of seals did not vary significantly.
Strongly Supported Conclusions
The population size of northern fur seals likely did not vary significantly over the 800-year period when they were hunted by Native Americans for food.
13.
The statements above, if true, ███████ ███ ████ ███████ ███ █████ ███ ██ ███ ██████████
a
During the 800-year ██████ ████████ ████ ███████ █████████ ███ ███ ████ █████████████ ███████ █████████ ██████ ██ ██████ ███████ ██ █████ ████████
This is unsupported because different hunting practices could occur at the same time that the seal body size and population remain constant.
b
The body size ██ ████████ ███ █████ ██ ███ ████████ ██████████ ████ ███ ███████ ██████ ██ ███ ██████
This is unsupported because the stimulus gives us no information to assess the health of the seals, which could be independent from population size.
c
Before the 800-year ██████ ████████ ███ ███████ ████ ████ ██ ████████ ███ █████ ██████████ █████████████
This is unsupported because the fossil evidence only covers the 800-year period, meaning we don’t know what happened before or after that period.
d
Native peoples in █████ ███████ ████ ██ ██████ ██ █████ █████ ███████ ██ ████████ ███ █████ ██ █████ ██ ███████ █████████ ██ ████ ████████████
This is unsupported because there could be many other reasons that explain the constant body size of seals outside of intentionally limited hunting practices.
e
Hunting by Native ███████ ██ █████ ███████ ███ ███ █████████████ ██████ ███ ████████ ███ ████ ██████████ ████ ███ ████████ ██████ ████████
This is strongly supported because if the Native peoples had significantly reduced the population, we would expect the average size of the seals to have changed.