Fingernails and toenails on the human body are from since the evolution of the species and these were very useful for the early people. They use them for climbing purposes. It has the same functions as the claws in the animals. At that time no tool was available for the human beings except that are found in nature and the nails that served them as the scrapers, cutters and tweezers.
Today nails have become evolutionary remnants and are used for the small purposes like to scratch and itch or to protect the tips of our fingers and toes. Nails are broad and slightly curved in shape. They are made up of keratinized structure, same substance of which the horns are made. These are found in the vertebrate animals while in crocodiles it is in the form of thimble shaped structure, in hawks and owls they are found as talons and also in horses and cows as hooves for the protection of their feet. So the fingernails protect the tips but at the same time do not obstruct the sensitivity and movement of the fingers. If sometimes a nail is removed then you have to take care of the skin below the nail because it is very sensitive and can allow the bacteria and germs to enter the body and the nail is not there which acts as the protective layer.
So we can say that today nails are of not much importance as twenty thousand years back. But of course they increase the beauty of womanâ€™s hand when painted with beautiful nail colors.