Washington, Apr 2 : While scratching they come really 'handy' and when painted, they add a girly shine to hands. But these are not the reasons for why we humans sport fingernails.
According to John Hawks, a biological anthropologist at the University of Wisconsin-Madison, we have nails because we're primates.
"We have fingernails because we're primates," Live Science quoted Hawks, as saying.
Fingernails are one of the features that distinguish primates, including humans, from other mammals. They are essentially flattened forms of claws.
"Most mammals have claws. [They] use them to grab onto things, to climb things, to scratch things, and to dig holes," he said.
Researchers suspect that primates sort of lost their claws and fashioned broad fingertips topped with nails to aid in locomotion.
While claws would have provided excellent grip as our mammalian ancestors clambered up large tree trunks, they would have been a nuisance for larger-bodied primates trying to grasp smaller branches while scrambling across tree canopies for fruits.
Rather, primates developed broader fingertips made for grasping, Hawks said.
He added that whether fingernails are an adaptation that helps to support broad fingertips or a side effect from the loss of claws is unclear.
According to him, another reason for fingernails is that they serve as a visual advertisement of a person's health. For instance, malnutrition can change the coloring of nails, while small pits in fingernails can signal the skin condition psoriasis.