Which characteristics do humans share with primates and which are unique to humans?

Answer 1

Humans are primates, and thus have all the defining characteristics for the clade of Primates along with the defining characteristics that are unique to Hominoidea (apes) and humans.

The key characteristics that make primates primates are:

• that primates are mammals, and thus have all the defining characteristics for the clade of Mammalia, except for the following:
• they have shorter snouts than most mammals
• they have different types of teeth: incisors, canines, molars, reflecting an omnivore's diet
• they have forward facing eye sockets, emphasizing sight (and depth perception)
• they have collarbones, aiding free motion of the arms
• they have radius and ulna, two bones in the forearm as well as the lower leg, aiding precision of movement
• they have nails in stead of claws
• they have increased thumb mobility compared to the other mammals
• they have grasping feet (this feature has decreased somewhat in humans, but is still apparent from our morphology)
• they tend towards a vertical posture
• forelimbs and hindlimbs are used differently
• they live longer than most other mammals, and appear newborn/young longer (other mammals have relatively short periods of 'childhood')
• they have larger brains than most other mammals
• they have reduced olfactory capabilities compared to most other mammals

So any clade that is part of the clade of Primates (such as the clade of Apes and our own species, humans) will share all of these features to some extent - although they may have been slightly modified over the generations:

• we've lost our tails (along with all other apes)
• we've grown increasingly large brains, compared to the other primates
• we (along with all other apes) have five cusps on our molars
• our arms are shorter and weaker
• our toes have shrunk and the 'thumb' has aligned with the other toes
• our feet have lengthened and formed an arch
• our legs have lengthened and grown stronger relatively to our arms
• we've lost most body hair, compared to the other apes, and the other primates
• our lower jaw juts forward, compared to the other apes and primates; this is accompanied by a virtually flat face and a high forehead

We share opposable thumbs, for instance. General morphologies and behavioral similarities. Humans are uniquely bipedal though as all the other great apes are knuckle walkers.

Answer 2

Humans share characteristics with primates such as opposable thumbs, forward-facing eyes, and the ability to use tools. Unique human characteristics include complex language, advanced problem-solving skills, and a high level of self-awareness and consciousness.