"Surprising" Phenomenon
Why did the human brain’s evolution take place almost entirely in the savnna and woodland rather than the shore, even though the food reources that could supply the high-calorie diet required for the brain’s development was more abundant in the shore?
Objective
The correct answer should help us differentiate the shore environment from the savanna and woodland in a way that could help explain why the brain’s development occurred in the savanna and woodland.
A
Early humans had a significantly lower metabolic rate than anatomically modern humans, allowing them to expend their fat reserves more efficiently.
This doesn’t differentiate the shore from the savanna and woodland. Even if early humans needed less fat, why did brain development occur in the savanna and woodland, which had less of the food resources required by the brain than did the shore? This doesn’t provide a theory.
B
The brains of the earliest known humans were 30 percent smaller than the anatomically modern human brain.
This doesn’t differentiate the shore from the savanna and woodland. Even if early humans had smaller brains, why did brain development occur in the savanna and woodland, which had less of the food resources required by the brain than did the shore? This doesn’t provide a theory.
C
Prehistoric savanna and woodland areas offered more reliable and abundant resources than they do today.
This compares savanna/woodland of the past to savanna/woodland of today. But it doesn’t compare the past savanna/woodland to the past shore environment. The stimulus still tells us that the past shore environment had more of the food resources than the past savanna/woodland.
D
The techniques used to explore the archaeology of prehistoric shore sites have only recently been developed.
This doesn’t suggest anything about the level of food resources available in the shore environment. Don’t assume that because the techniques were recently developed that we should doubt the facts given to us in the stimulus.
E
Gathering food in shore environments required a significantly greater expenditure of calories by early humans than did gathering food in other environments.
If it cost more in calories to gather food in the shore than it did to gather food in the savanna/woodland, this extra cost could have outweighed the benefit of more food in the shore. It’s possible overall calorie intake could be higher in the savanna/woodland than in the shore.
Summarize Argument: Counter-Position
Terrence Gurney is incorrect in believing that he has not received sufficient credit for his literary achievements because his books are popular with a wide audience. It is more likely that Gurney has not received much praise for literary achievement because his writing is flat and leaves no lasting impression on the reader.
Identify Conclusion
The stimulus's conclusion is the author's opinion that Terrence Gurney is mistaken. Specifically, the author concludes that Gurney is wrong in thinking he hasn't received enough credit for his literary achievements simply because his books appeal to a wide audience.
A
Terrence Gurney is mistaken when he suggests that the wide appeal of his books has prevented him from being given due credit for his literary achievements.
This reflects the main conclusion that Terrence Gurney is operating under an incorrect belief. The stimulus supports this by providing an alternative reason for why Gurney has not received literary praise, stating that Gurney’s writing is flat and leaves no lasting impression.
B
Terrence Gurney’s books are not significant literary achievements.
This misstates a claim in the argument’s context. The author notes that Gurney believes he hasn’t received enough credit for his literary achievements. However, (B) incorrectly interprets this as a claim that Gurney’s books are objectively not significant literary achievements.
C
Even though Terrence Gurney’s books tell interesting stories, his writing is flat and leaves no lasting impression on the reader.
This restates a premise. The author cites Gurney’s flat writing and lack of lasting impression to support the conclusion that Gurney is mistaken about why he hasn't received credit for his literary achievements. Since this supports another claim, it can’t be the main conclusion.
D
Terrence Gurney has not been given due credit for his literary achievements because his books appeal to such a wide audience.
This statement is context. It describes Gurney’s belief, which the author disputes. By explaining Gurney’s belief, this context provides the background needed to understand the author’s counterargument that Gurney’s belief is incorrect.
E
Terrence Gurney should have received some praise for his literary achievements despite the fact that his writing is flat and leaves no lasting impression on the reader.
This is not a claim made in the argument. The author simply explains why Gurney has not received praise for his literary achievements. The author does not discuss whether Gurney’s lack of praise is deserved or not.
"Surprising" Phenomenon
How could lightning have produced the first amino acids on Earth, even though Earth’s atmosphere at that time had a lot of oxygen, and amino acids break apart unless the spark that produced them occurs in an atmosphere that has a lot of hydrogen and not much oxygen (a “reducing” atmosphere)?
Objective
The correct answer should explain how there still could have been a “reducing” atmosphere necessary to allow the first amino acids to form and persist, even though Earth’s atmosphere had a lot of oxygen (and so was not a “reducing” atmosphere).
A
Meteorite impacts at the time life began on Earth temporarily created a reducing atmosphere around the impact site.
This raises the possibility that lightning could have produced amino acids around the impact sites of meteors, which temporarily had a reducing atmosphere.
B
A single amino acid could have been sufficient to begin the formation of life on Earth.
This doesn’t address how an amino acid could have formed and avoided breaking apart in an atmosphere that wasn’t reducing. If there was no reducing atmosphere, how would that single amino acid have come about?
C
Earth’s atmosphere has changed significantly since life first began.
The current atmosphere doesn’t matter, since the stimulus tells us Earth’s atmosphere “was” - meaning, at the time of the first amino acids - rich in oxygen. So, if the atmosphere wasn’t reducing, how could the amino acids form and avoid breaking apart?
D
Lightning was less common on Earth at the time life began than it is now.
But if there was lightning, however rare it was, how could that have produced amino acids in a non-reducing atmosphere? This doesn’t provide a theory about how this happened.
E
Asteroids contain amino acids, and some of these amino acids could survive an asteroid’s impact with Earth.
We’re interested in explaining how lightning could have produced the first amino acids. It doesn’t matter whether asteroids could have already had amino acids. Those aren’t amino acids produced by lightning on Earth.