EVERYDAY SCIENCE

Detailed explanation-1: -Opposable thumbs/toes are a derived trait that appeared in the earliest primates about 55 million years ago. Having thumbs and big toes that go in a different direction from the rest of the fingers and toes allow primates to be excellent climbers in trees but also allow us to manipulate objects.

Detailed explanation-2: -What makes human hands unique? The human opposable thumb is longer, compared to finger length, than any other primate thumb. This long thumb and its ability to easily touch the other fingers allow humans to firmly grasp and manipulate objects of many different shapes.

Detailed explanation-3: -The evolution of the fully opposable thumb is usually associated with Homo habilis, a forerunner of Homo sapiens. This, however, is the suggested result of evolution from Homo erectus (around 1 mya) via a series of intermediate anthropoid stages, and is therefore a much more complicated link.

Detailed explanation-4: -Primate derived traits include opposable thumb and big toe, prehensile hands and feet, nails instead of claws on the digits, ability to sit for extended periods of time in an upright position without using the upper limbs for balance, reliance on vision, and reduced sense of smell.

Detailed explanation-5: -We share a number of derived features with living apes that distinguish us from other primates: tail loss, upright posture, shortened trunks, enhanced grasping capabilities, large brains relative to body size, flexible forelimbs, slow maturation, and a long life span.