Which of these body parts can only be found in human beings?
Thumb
Chin
Knuckles
Ankle
Fact: The chin is unique to humans. While many animals have features like thumbs, knuckles, and ankles, only humans have a distinct, forward-projecting chin. Even chimpanzees and gorillas, our closest genetic cousins, lack chins. Anatomically, the chin is the part of the lower jaw that juts out beneath the mouth, and no other primates—or any other animals—have this feature. Scientists are still unsure why the human chin evolved, but it may be related to speech or chewing mechanics. Whatever the reason, the chin remains one of the most uniquely human traits.
Correct Answer: Chin