When you think of all the things your fingernails help do, it makes sense that evolutionary adaptation didn’t eliminate them (unlike the tail). You can peel an orange easily, undo knots, scratch an itch, and pick your nose, all with the help of fingernails. They can even function as an early warning sign of potential malnutrition or health risks.
And how about toenails? Why do we have toenails? Early humans were thought to use all four limbs for climbing, and toenails definitely help with gripping (think about longer, thick, claw-like nails that early humans would have had). Useful back then, but why do we still have toenails? Why do humans have nails, period? Read on to discover all the fascinating reasons why humans have nails!
There Is Debate Over the Origin of Fingernails
Today, we use tools way more than other primates – though there are some orangutans getting too clever for their own good – so it makes sense that our fingertips remain the broadest in the primate kingdom. You might say we evolved to need claws the least, so our claws followed suit and became very un-clawlike.
It’s All About the Branches
Researchers believe T. brandti evolved its tiny nails – and in a sense, our nails? – to make it easier to grasp small branches, as well as hold on to food. They’re the smallest “true” fingernails on record, but they may have offered a big advantage to T. brandti.
Fingernails Are Perfect for Certain Manipulations
The theory that humans using tools caused our fingernails to get less and less claw-like has support in the evolution of the so-called “grooming claw” or “toilet claw” in certain primates. Like it sounds, it’s a specialized nail used for personal grooming. Perhaps the use of tools prohibited humans from evolving this nifty nail? Regardless, the nails we know and love (and chew) today still prove useful in a number of applications.
In the Distant Past, Fingernails Helped Humans Capture Body Lice
Unfortunately, gorillas may have given early Homo sapiens one kind of lice that their fingernails were no match for: pubic lice. That doesn’t mean anything “unnatural” was going on (not necessarily); we may have gotten them from living near gorillas or killing them for their meat.
Fingernails May Have Inspired Early Weapons and Tools
Colin McGin argues in his Prehension: The Hand and the Emergence of Humanity that early humans drew inspiration from their fingernails: “the fingernails themselves provide an excellent prototype for tools designed to score and tear – the ingenious early human just needed to make sharper and more powerful nail-like implements.”
It’s an intriguing and romantic thought: early humans, inspired by their own bodies to create an extension of their bodies.
Reasons Why We Still Have Toenails Are Hotly Debated
They Protect Our Fingers
Horse hooves, similarly, have no nerve endings, allowing us to “shoe” them the way we do. We don’t put our nails through that kind of punishment, but think how many more broken thumbs there would be in the world if the “shield” of a thumbnail wasn’t there to absorb the blow of a hammer?
They Provide Support (By Getting Out of the Way)
Ryan says that nails “allow the fingers and toes to be spread flat which provides a more solid support for the hands and feet during grasping.” So along with added grip on branches in the treetops from broader fingertips, our lack of claws let primates and early humans use their palms for extra support.
Nails Are Indicators for Certain Health Conditions
Nails Are Also Indicators of Overall Health and Nutrition
Research has shown that not getting enough vitamin B12, for example, can cause brown-gray nail discoloration. Pink or red nails that got that way without nail polish suggest malnutrition, which is ironic, considering that those colors are considered healthy and sexy when artificial.