Final answer:
The three key features that distinguish humans from other primates are an upright posture and bipedalism, an increased brain size with advanced cognitive functions, and reduced bone mass in facial and cranial structures.
Step-by-step explanation:
The three things that set humans apart from other primates include:
- Upright posture and bipedalism: Humans have a fully upright posture which results in the ability to walk on two limbs (bipedalism), as opposed to using four limbs for locomotion, which is common in other primates.
- Brain size and function: An increase in brain size, especially in the frontal lobes, gives humans a significant capacity for abstract thought, resulting in unparalleled technological and cultural advances.
- Reduced bone mass in facial and cranial structures: A decrease in bone mass in the skull and face lends to a distinct phenotype, contributing to the various expressions and speech capabilities unique to humans.
While these features set us apart, it is important to note that there are many similarities we share with other primates, such as having opposable thumbs, flat nails, and large brains relative to body size. Moreover, our DNA sequences share a high degree of similarity with other primates, supporting the evolutionary relationship.