medium · SAT Reading & Writing

Anthropologist Dr. Elena Ruiz argues that the 'domestication' of fire by early hominids was the primary driver of human brain expansion. By cooking food, humans could access more calories with less digestive effort, allowing the body to redirect energy from a large gut to a larger brain. Ruiz notes that this metabolic trade-off is evidenced by the relatively small digestive tracts of modern humans compared to other primates. Based on the text, how did cooking food contribute to brain growth?

1. It allowed humans to survive exclusively on cooked plant matter for the first time.
2. Other primates are incapable of domesticating fire because of their large digestive tracts.
3. It caused a physical increase in the size of the human gut over several generations.
4. It enabled the reallocation of metabolic energy by reducing the demands of the digestive system.

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