We and our fellow primates have these things growing out of our fingers (and toes, for that matter). They seem like they evolved from claws, but they don’t seem especially valuable for self defense, climbing trees, traction, or the other things that other mammals use them for. I guess they would have some value for digging or as a crude tool.
Are nails just vestigial traces of prior functionalilty, or did they evolve because they provide a real survival benefit?
You ever tried to pick a booger with a hot dog weenie?
I’m with Lieu. I can still smell that oscar meyer, and it was extracted from my nose last night.
(I get a discount rate at the 24 hour clinic for this)
Or scratch your butt?
I’m thinking they’re kept on some I can open the blades on my pocket knife.
No kidding, Lady Chance has these paper thing nails (she calls them ‘irish nails’) and can’t open a blade for love nor money.
They may not be as effective as claws, but a finger with a fingernail is better than one without, and is also better suited to the more delicate work that we do with them, e.g. using tools, picking up small objects, etc. The nails don’t get in the way as much as claws would.
Could they offer some very low level of protection?
Yeah its a long shot, just throwing it into the mix.
One theory: flat fingernails increase tactile sensation on the digital pads by providing a back that gives even pressure when we touch something.
They make it much easier to pick fleas and lice out of your hair.
And even if we didn’t need “claws” at all, you wouldn’t expect them to just disappear overnight. A lot of body parts and systems persist in some form even after they no longer have a use, and sometimes develop new uses (how many different uses do various animals have for their tails, for instance?).
I had a teacher that told me that nails help to even out the pressure on your fingers. Plus there is the scratching aspect.
An odd thing is my index and middle finger nails constantly pop up off the skin. I have about 1/5 of the nail come up on a regular basis. Could this be the first sign of a loss of nails in the human species?
x-files theme
Either that, or there was a fly in your telepod.
Now that you mention it…
how would scratching be represented in the evolutionary process? Wouldn’t systems dissapear only if they contributed to a degradation of survivability? I can’t see where not being able to scratch your behind would lead to your death.
Well if a potential mate comes by, is he or she going to pick the person who’s already scratched and is standing around, or the one who went over to a tree to scratch their backside like a dog?
Somewhat related to the OP, why is the tissue underneath your fingernails so sensitive? It seems rather pointless to have a bunch of nerve endings under a great slab of keratin.
-Oli
um, the nerves are all over your fingers, why wouldnt they be under your nails? that and if you remove the protective layer from any part of your body I would be willing to bet that whats underneath is sensative as hell.
someone peel off all your skin and tell us how if feels!
Evolution isn’t a design process that has any motivation behind it. It’s just a case of “Is this detrimental to this creature’s life? No? Then it stays.” kind of situation.
Fingernails are left overs from claws, which are great for digging, scratching the enemy, and a few other things, and are in no way detrimental to our way of living, so they never fell by the wayside.
I would think that scratching was a vital process for getting rid of various parasites - very important evolutionarily.
Plus fingernails are still useful, just in more refined fashion.