PrepTest 145, Section 2, Question 2
Anthropologist: One of the distinctive traits of humans(63 more words not shown)
Which one of the following,(7 more words not shown)
- ACooked foods contain(8 more words not shown)
- BRaw meat contains(9 more words not shown)
- CThe human body(15 more words not shown)
- DThe human body(14 more words not shown)
- EDomesticated plants and(10 more words not shown)
Reading the argument
How do we fuel a large brain with a small gut? Cooking could help if it makes food easier to digest. That is a plausible explanation, and the difficulty some raw-food eaters have getting enough calories gives it some support.
But the timing doesn't settle what caused what. Large brains developed around the time our ancestors began controlling fire. What if a larger brain helped them figure out how to control fire? In that case, the brain would help explain the cooking, rather than cooking explaining the brain. Or perhaps a change in how well their intestines worked allowed them to get enough energy. The two developments occurring together doesn't rule out those possibilities.
What we’re looking for
We're asked to strengthen the cooking explanation. My first thought is to establish the order: did control of fire come early enough to help the larger brain develop? Evidence separating the benefit of cooking from some other digestive change could also help. We want a reason to believe cooking contributed to this energy advantage.
Working the answers
- A
The number of calories in the food doesn't tell us how much energy the body ends up with after processing it. Equal calorie contents don't establish an advantage for cooking, so A doesn't strengthen the explanation. But we shouldn't jump to 'cooking cannot help at all': the body might spend less energy processing cooked food even if the food starts with the same number of calories.
- B
This compares raw meat with raw vegetables. We need to compare eating food cooked with eating it raw. Meat containing more calories than vegetables doesn't show what cooking contributes to either diet.
- C
Extracting the same number of calories from each kind of food gives us no positive reason to credit cooking. Still, extracting calories and spending calories to process food are different matters. Equal extraction could coexist with a lower processing cost for cooked food. C doesn't establish that benefit; it simply leaves it unresolved.
- DCorrect
Cooking saves energy that would otherwise go into processing the food. Suppose the body extracts 100 calories either way, but spends 30 processing the raw food and only 10 processing the cooked food. It would have 70 left in the first case and 90 in the second. The food needn't contain more calories for cooking to leave more energy available to support the brain.
This isn't the timing evidence I predicted. It doesn't establish that fire came before the larger brain, and it doesn't eliminate every alternative explanation. Instead, it gives a concrete reason cooking could make a smaller amount of food go further. That makes the anthropologist's explanation more believable, which is all a strengthener needs to do.
- E
Domesticated versus wild is another different comparison. Either type of plant or animal could be eaten raw or cooked. E doesn't show that cooking accounts for the energy advantage.
More Strengthen questions
Learn the LSAT our way
Our platform drills Strengthen questions at your level and adjusts as you improve.