Self-study
Researcher: It is commonly believed that species belonging to the same biological order, such as rodents, descended from a single common ancestor. ████████ █ ████████ ███ ███████ ███████ ██ █ ██████ ████████████████ █████ █████ ███ █████████ ████ ██ ██ ██ █████████ ████████ ███ █████ ████ █████ ████ ███ ████ ███ ███████████ █████ ████████ ███ ███████ ███████████ ███████ ██████ ████ ███ ████ ███ ██ █████ ██ █████ ███████ ████ ███ ████ █████████ ████████ █████ ███████ █████ ███████ ████████ █████ ██████ ████ ████ ████ █ ████████ █████████
Summarize Argument: Phenomenon-Hypothesis
The researcher hypothesizes that guinea pigs do not share a common ancestor with mice. Although guinea pigs and mice are both rodents, the researcher found that they have very different genetic patterns—as different as between mice and some nonrodent species.
Notable Assumptions
The researcher assumes that dissimilar genetic patterns are sufficient to conclude that two species have separate ancestors.
26.
Which one of the following, ██ █████ ████ █████████ ██████████ ███ ████████████ ██████████
a
The researcher examined ███ ███████ ████████ ██ ████ █ ██ ████ █████ ███████ ██ ████████
This does not affect the argument. The researcher hypothesizes that guinea pigs and mice stem from separate ancestors based on her finding that they have dissimilar genetic patterns—the researcher does not make an argument about rodents broadly.
b
Some pairs of ███████ ███ ██████ █ ██████ ████████ ███ ███████████ ████ ███████ ██ ████ █████ ████ ███ ████ █████ ████ ██ ████ █ ██████ █████████
This weakens the argument. It attacks the researcher’s assumption that dissimilarity in genetic patterns is enough to conclude two species lack a single common ancestor by noting that some species who do share an ancestor also lack similar genetic patterns.
c
The researcher selected █████████ ███████ ████ ████ ███ ████████ ████ ██████████ ███ ██████ ██ ███████ ████████████ ██████ ████ █████████ ███████ ████ █████ ████ ███████████
This does not affect the argument. The researcher only claims that the genetic difference between mice and guinea pigs is as great as between mice and “some” nonrodent species.
d
For some genuine ██████████ ███████ ███ ████ ██████ ██████ ████████ █████ ████ █████ ██████ ████ ████ ███ ████ ██████ ██████ ████████ ██ █████ ██████████ ███████
This does not affect the argument, which is that given their dissimilar genetic patterns, mice and guinea pigs do not share a single common ancestor at all. The recency of a common ancestor is irrelevant.
e
Peculiarities of body ██████████ ████ ██ ███████████ █████ ███ █████████ ███████████ ███ ██████ ██ ███ ████████ █████████ ██████ █████
This does not affect the argument, which already notes that guinea pigs and mice share similar physical forms.