Charles Darwin noted that nonhuman primates have the same facial muscles as humans and proposed that emotional expressions
A) only appear in the primate lineage.
B) may have originated in a common ancestor.
C) are a novel evolutionary trait.
D) are a sexually selected trait.

Question

Quizplus · Accepted Answer

Charles Darwin proposed that emotional expressions may have originated in a common ancestor, meaning that nonhuman primates have similar facial muscles as humans because they inherited them from their shared evolutionary ancestor. This suggests that emotional expressions are not a novel evolutionary trait that only arose in humans or one particular primate lineage.

Charles Darwin Noted That Nonhuman Primates Have the Same Facial