CHIMPANZEE HAND STRUCTURE MANUALS
CHIMPANZEE HAND STRUCTURE MANUAL

Image by Denise Morgan for the University of Utah, via Wikimedia Commons. The design of the chimpanzee’s hand is far more suitable than a human’s for swinging through trees.

Unlike the chimp’s hand, the uniquely designed human hand has a fully opposable thumb and is able to clench into a tight fist. The chimpanzee’s hand (left) has much longer fingers, a longer palm, and a shorter thumb than the human hand (right). 8 But which bony proportions came first? What was the hand of the evolutionary common ancestor of humans and apes like? That’s the question Sergio Almécija and colleagues have tried to answer in their study recently published in Nature Communications. With longer thumbs and shorter fingers in addition to their unique bony contours, human hands differ markedly from those of long-fingered monkeys and arboreal apes like chimpanzees and orangutans. 7 The Better to Swing from Trees, My Dear. 5 Given the appearance of this shape in a thumb bone dated so very early in the ape-like hominid-to-human evolutionary tale, Almécija has maintained since 2010 6 that the human grip is a primitive feature that long preceded the mental capacity to make tools. 4 The identity of Orrorin’s very fragmentary skeleton and its possible relationship to Homo remains in dispute but would never be considered Homo as evolutionary dogma could never accommodate the existence of a human alleged to be 3 million years older than australopithecine apes. 3 Interestingly, the thumb bone from Orrorin tugenesis-an incomplete collection of human-like bones and teeth that evolutionists date at 5.7 to 6.1 million years-does have these typically human curves. Australopithecines also lack these grip-enhancing contours. They can only manipulate small objects by gripping them between the thumb and index finger tip-to-tip or pad-to-side, a pad-to-pad grip being impossible for them. Living great apes like chimpanzees and gorillas do not have these bony contours. Image by Sergio Almécija, Salvador Moyà-Solà, and David Alba, via PLoS ONE. And beyond that is another more shallow depression (in blue) for the soft tissue of the thumb’s tip ( distal ungula pulp), which being smaller and less mobile is able to securely grasp a tiny object. Just beyond this tendon’s insertion, an especially large depression (in green) accommodates the bulky soft tissue of the thumb pad ( proximal ungual pulp), which is soft and mobile enough to adapt to the shape of an object being grasped. As shown above, the tendon (shown in red) that enables you to freely flex the end of your thumb is accommodated by a particularly large depression (in orange, proximopalmar fossa). Each curve in the contour of the bone at the end of the thumb ( pollical distal phalanx) enhances the human ability to feel and grip tiny objects gingerly but securely. Your human ability to nimbly hold and manipulate objects between your thumb and any one of your fingers depends on more than the ideally designed proportions of your thumb, finger, and hand bones. Almécija’s analysis of primate thumb-and-finger proportions published in Nature Communications overturns the view that we humans evolved our hands from chimp-like ancestors in favor of the notion that chimps evolved their hands from hands like ours.

CHIMPANZEE HAND STRUCTURE MANUAL

Such manual dexterity presumably gave our ancestors something to think about and made the manufacture of tools move past the fashioning of stone axes so they could adapt and evolve to hoist themselves into the modern world. “Chimpanzees have actually evolved more than humans.” 1Įvolutionary wisdom holds that humans developed big brains and creative powers after coming down from the trees and evolving hands capable of manipulating the world around them. “Human hands have not changed that much since they diverged from chimpanzees,” Almécija says. They believe the human hand’s precision grip is not advanced but instead represents the primitive condition much like that of the last common ancestor shared with apes. They are challenging the view that humans diverged from chimp-like ancestors with hands adapted to swing from tree limbs. Evolutionary researcher Sergio Almécija and colleagues have knocked the pins from under that bit of conventional evolutionary thinking.

CHIMPANZEE HAND STRUCTURE MANUALS

Thumbing through the pages of most manuals on human evolutionary history, a reader would soon latch onto the idea that our precision grip was a relatively recent addition to the human repertoire.

Nature World Report: “ Chimps vs Humans-Whose Hands Are More Primitive?”.

Science: “ Humans Have More Primitive Hands Than Chimpanzees”.

Chimpanzee hand structure