Why do we have fingernails?
Thanks!
Scratcher
Dear Scratcher (or Rub-er),
This is either a great question or an idle musing. Try this: Wrap all ten of your fingernails with tape. Now, try to carry on with your regular day. You'll find that fingernails help us scrape and scratch all kinds of things.
Start with washing your hair. Fingernails help you scratch your scalp and get the shampoo all the way to the head-ends of your hairs. Now, get some bread out of a bag to make toast. Without the sharp edge of your nails, it's not so easy. You'll notice right away that you can't scratch an itch. Try opening a ketchup packet at the fast food restaurant with your thumbnail taped over. We use our nails all day to get a grip and start a rip.
Ask Bill Nye
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Ask Bill Nye!
Fingernails have a few properties that are worthy of a head scratch (ha!). First of all, they're on your fingertips, right where you can direct them to handle all sorts of tasks. Then, they're hard. They cut into softer materials like corn husks, pea pods, and bark. This helps us feed ourselves and shape our shelters. They're made of keratin, a protein you make from your food. Since we're always wearing them down, they're always growing. They are created from the soft tissue underneath, the root or "quick" of your nail.
Because fingernails scrape and cut into so many things in nature, germs can live underneath them. So, keep your nails clean, and don't bite them. It can make you sick and make your hands look worn. We all notice nails. That's probably why so many women and a few men paint and polish them. They're the way your hands make a first impression.
Our nails are the big-brained version of claws. You need 'em. So eat right. Keep them clean. And scratch on.
See more of Bill Nye's answers to questions about science.
http://encarta.msn.com/encnet/features/columns/?article=BN_fingernails
