Summarize Argument
The author argues that the survival of every currently existing species is not necessary for biodiversity. To support life, various ecological roles must be occupied, and many of these roles can be occupied by multiple species.
Identify Conclusion
The conclusion is that the survival of every species that exists today is not necessary for biodiversity: “biodiversity does not require the survival of every currently existing species.”
A
Biodiversity does not require that all existing species continue to exist.
This rephrases the conclusion.
B
There are various ecological niches that must be filled if there is to be life on Earth.
This is context. It provides background that is important for understanding the premise, which is that many of these niches can be filled by more than one species.
C
The survival of life on Earth depends upon biodiversity.
This is context. While important for understanding the overall argument, it is not the conclusion.
D
There are many ecological niches that can be filled by more than one species.
This is a premise. It provides support for why biodiversity does not require every currently existing species to survive.
E
The species most indispensable for biodiversity fill more than one ecological niche.
This is not an idea that is discussed in the stimulus.
Summarize Argument: Phenomenon-Hypothesis
The author hypothesizes that chocolate interferes with one’s ability to taste coffee. Her evidence is an experiment showing that the group who ate chocolate wasn’t able to taste the differences between coffee samples, whereas the group that didn’t eat chocolate were able to taste the differences.
Notable Assumptions
The author assumes that there was no relevant difference between the two groups in the experiment besides the fact that one group had eaten chocolate. Any relevant difference between the two groups would call into question the author’s hypothesis. The author also assumes that a single experiment with ten people is sufficient to draw conclusions about how chocolate affects one’s ability to taste coffee.
A
The ten people were randomly assigned to either the group that tasted only coffee or the group that was also given chocolate, although some people had asked to be in the group that received chocolate.
Well, those people who wanted to be in the chocolate group were nevertheless randomly assigned. The experiment remains intact.
B
Similar results were achieved when the experiment was repeated with a different, larger group of people.
This strengthens the author’s argument by shoring up the sample size issue.
C
Chocolate is normally consumed as a solid, whereas coffee is normally consumed as a liquid.
This is true. But how does this affect the author’s argument? We need to weaken the connection between eating chocolate and not being able to taste the differences between coffee samples.
D
The five people who were originally given chocolate were asked a week later to taste coffee samples without chocolate, and they still detected no differences between the coffee samples.
The five people in the chocolate group simply have no ability to taste the differences between coffee samples. Once chocolate was removed as a variable, the results of the experiment remained exactly the same.
E
Some subjects who tasted just coffee reported only subtle differences between the coffee samples, while others thought the differences were considerable.
Regardless of the strength of the differences, these people all noted differences. People in the chocolate group didn’t note any differences.