This difference brought on by evolution, allows us to clench our hand into a fist whenever we fold our thumb across the fingertips. (Photo: Denise Morgan for the University of Utah) Three views of a clenched human fist show how we buttress the fist to reduce the chance of hand injury when punching. Modern chimpanzees, according to Carrier, have long palms and fingers with a short thumb, while the human palm and fingers are much shorter and the thumb longer and stronger. While the human hand evolved to allow great dexterity, according to Carrier, a chimpanzee can also manipulate its hands in a way that would give it greater manual dexterity, but they still may not necessarily be able to form their hands like humans do. In the course of their conversation, Frank Fish, an expert in biomechanics, formed a fist and said, “I can hit you in the face with this, but that is not what it evolved for.”įish’s proclamation made Carrier stop and think. In a study published in The Journal of Experimental Biology, University of Utah scientists theorize human hands evolved their unique square palms and long thumb in order to stabilize the fist, providing a built-in compact club early humans could use in combat.Īn impassioned conversation with a colleague inspired David Carrier to pursue research on the matter. New research suggests the evolution of the modern human hand may be due to a very basic need: for use as a weapon. Refined through centuries of evolution, hands enable us to perform unique functions which help us to not only survive but also to thrive as a species. The human hand is a sophisticated work of art and science. It was only much later that our larger brains and more complex technology set us apart as Homo sapiens.A clenched human fist (Photo: Ralpharama via Wikimedia Commons) increasingly complex forms of technologyįossil evidence shows that our ancestors became bipeds first, followed by changes to the teeth and jaws. bipedalism (walking upright on two legs) 2.These can be summarised as trends involving the development of: Our own species Homo sapiens is the result of four major evolutionary changes. The ancestral line that led to modern chimpanzees also changed, possibly with changes that were as dramatic as our own. Millions of years of evolutionary change and natural selection meant that later hominin species were less apelike in appearance and behaviour than their early ancestors. It is highly likely that A.ramidus preserves some of the characteristics of the last common ancestor, suggesting that some of its features (particularly in the limbs and hands) were more like those in living monkeys and early apes like Proconsul. The fact that A.ramidus has a number of physical features that differ significantly from chimpanzees (particularly those that show it was not a knuckle-walker) is crucial to our understanding of hominin and ape evolution. This species dates to a critical time in hominin evolution as it is nearing the time when scientists believe hominins diverged from the ape branch of the family tree. Recent studies on the skeleton of the 4.4-million-year-old Ardipithecus ramidus have changed all this. However, this lacked supportive fossil evidence as there are almost no fossils of early chimps or gorillas and very few of early hominins. This view was based on the beliefs that our ancestors probably passed through a proto-ape stage and that African apes are less specialised than humans so have changed less since diverging from this ancestor. Until recently it was widely believed that it looked much like a chimpanzee, with features such as a short back, arms and hands adapted for grasping and swinging in branches, and wrists and forelimbs that enabled knuckle-walking. What this common ancestor looked like is not known. Most scientists believe that the ‘human’ family tree (known as the sub-group hominin) split from the chimpanzees and other apes about five to seven million years ago. Evidence from fossils, proteins and genetic studies indicates that humans and chimpanzees had a common ancestor millions of years ago.
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