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Why can’t I wiggle my toes individually, like I can with my fingers? – Vincent, age 15, Arlington, Virginia
One of my favorite activities is going to the zoo where I live in Knoxville when it first opens and the animals are most active. On one recent weekend, I headed to the chimpanzees first.
Their breakfast was still scattered around their enclosure for them to find. Ripley, one of the male chimpanzees, quickly gathered up some fruits and vegetables, sometimes using his feet almost like hands. After he ate, he used his feet to grab the fire hoses hanging around the enclosure and even held pieces of straw and other toys in his toes.
I found myself feeling a bit envious. Why can’t people use our feet like this, quickly and easily grasping things with our toes just as easily as we do with our fingers?
I’m a biological anthropologist who studies the biomechanics of the modern human foot and ankle, using mechanical principles of movement to understand how forces affect the shape of our bodies and how humans have changed over time. Your muscles, brain and how human feet evolved all play a part in why you can’t wiggle individual toes one by one.
Chimpanzee hands and feet do similar jobs.
Manoj Shah/Stone via Getty Images
Comparing humans to a close relative
Humans are primates, which means we belong to the same group of animals that includes apes like Riley the chimp. In fact, chimpanzees are our closest genetic relatives, sharing almost 98.8% of our DNA.
Evolution is part of the answer to why chimpanzees have such dexterous toes while ours seem much more clumsy.
Our very ancient ancestors probably moved around the way chimpanzees do, using both their arms and legs. But over time our lineage started walking on two legs. Human feet needed to change to help us stay balanced and to support our bodies as we walk upright. It became less important for our toes to move individually than to keep us from toppling over as we moved through the world in this new way.
Feet adapted so we could walk and balance on just two legs.
Karina Mansfield/Moment via Getty Images
Human hands became more important for things such as using tools, one of the hallmark skills of human beings. Over time, our fingers became better at moving on their own. People use their hands to do lots of things, such as drawing, texting or playing a musical instrument. Even typing this article is possible only because my fingers can make small, careful and controlled movements.
People’s feet and hands evolved for different purposes.
Muscles that move your fingers or toes
Evolution brought these differences about by physically adapting our muscles, bones and tendons to better support walking…
