Howler monkeys have smaller brains than equally sized spider monkeys. This is thought to stem from the fact that: A.howler monkeys eat less fruit than spider monkeys. B.howler monkeys eat less meat than spider monkeys. C.howler monkeys eat more fruit than spider monkeys. D.howler monkeys live in larger social groups than spider monkeys

Howler monkeys have smaller brains than equally sized spider monkeys. This is thought to stem from the fact that:
A.howler monkeys eat less fruit than spider monkeys.
B.howler monkeys eat less meat than spider monkeys.
C.howler monkeys eat more fruit than spider monkeys.
D.howler monkeys live in larger social groups than spider monkeys

Answer

• A.howler monkeys eat less fruit than spider monkeys.
  Explanation:
  Research suggests that monkeys who thrive on fruit have a bigger brain than their plant eating counterparts. Spider monkeys relies more on fruits because their digestive tract is not well equipped to provide sufficient energy by fermenting leaves. The high reliance on fruits is the main factor behind larger brains than the howlers who eat leaves