Self-study
A study of rabbits in the 1940s convinced many biologists that parthenogenesis—reproduction without fertilization of an egg—sometimes occurs in mammals. ████████ ███ ███████ ███████ ████ █████ ████ █████ ██ ██ ███████ ███ ██ █████ ███████ ████ █████████ ██ █████████████ █████████ ████████████████ █████ █████ ███████████████ ██ █████ ██ █████ ██ █ ████ ███████ ██ ████████████ ████████████ █████ ████ ██ █████████ █████ █████████ ███████████ ████ █████████ ███ ███████████ ██ ████████████████
Summarize Argument: Counter-Position
Many biologists think that parthenogenesis sometimes occurs in mammals. This belief is based on a study of rabbits.
The author concludes that the biologists’ view is wrong, because the study’s methods were flawed, and no other studies have shown parthenogenesis in mammals. In addition, parthenogenesis is known to occur in nonmammals.
Identify and Describe Flaw
The author assumes that the failure of the study to prove the biologists’ view is evidence that the biologists’ view is wrong. The author also assumes that failure of other studies to prove the biologists’ view is additional evidence the biologists’ view is wrong. This overlooks the difference between lack of support and a false conclusion. There might be a lack of support for the biologists’ view, but that doesn’t mean the view is false.
20.
A flaw in the reasoning ██ ███ ████████ ██ ████ ███ ████████
a
takes for granted ████ █████████ ████ ███ ███ ████ ██████ ██ ██ ████ ██ ███ ████ ██████ █████ ██ ██ █████
The author assumes that because parthenogenesis has not been proven to occur in mammals, that it does not occur in mammals. This is flawed because it’s possible parthenogenesis. does occur in mammals, even if it hasn’t yet been proven.
b
infers that a ██████████████ ██ ██████ ██ ███ ████████████ ██████████ ███████ ██████ ███████ ██ ██ ██████ ██ ████ ████████████ ██████████ ███████
The author states that parthenogenesis is known to occur in a “wide variety” of nonmammal vertebrates. That doesn’t mean the author believes parthenogenesis ocurs in “all” nonmammalian vertebrates.
c
rules out an ███████████ ██ █ ██████████ ██████ ██ ███ ███████ ████ █████ ██ ███████ ███████████ ████ ███ ███████ ███ ███ ██████████
The author doesn’t point to an alternate explanation of parthenogenesis. Also, the issue is whether parthenogenesis occurs in mammals, not what explains the phenomenon of parthenogenesis.
d
confuses a necessary █████████ ███ ███████████████ ████ █ ██████████ █████████ ███ ██
There are no necessary or sufficient conditions for parthenogenesis described in the premises or the conclusion. So there cannot be a confusion of a necessary condition for parthenogenesis with a sufficient condition.
e
assumes that the ███████ ████ ██ █ █████ ██ ███ █████████ ███████ ████ ██████ ██████ ███████ ███ ███████ ████████ ██████ ██ ███████████ ██ ███ █████ █████████ ███████
The claim that the study’s methods were flawed is a premise. We don’t know why the author believes the study’s methods were flawed, so we cannot say the author assumed anything regarding why the studies were flawed.