Answer:
What makes human hands unique? ... This long thumb and its ability to easily touch the other fingers allow humans to firmly grasp and manipulate objects of many different shapes. The human hand can grip with strength and with fine control, so it can throw a baseball or sign a name on the dotted line.
Humans, as well as monkeys, gorillas, and other primates, have a hand that can grip and grasp objects because they have an opposable thumb. The earliest primates were arboreal (they climbed trees), and so having grasping hands was an advantage in this environment. Human thumbs modified their ancestors’ opposable thumbs, making them more mobile and thus even more opposable.