• Question: what are finger/toenails for

    Asked by simeons to Betul, Bridget, Ceri-Wyn, Laurel, Maria on 22 Jun 2010 in Categories: .
    • Photo: Laurel Fogarty

      Laurel Fogarty answered on 20 Jun 2010:

      Fingernails and toenails protect the tips of the fingers and toes and make them stronger. Fingernails also make us more dexterous- we can pick up and manipulate smaller things than just with our fingers alone.

    • Photo: Ceri-Wyn Thomas

      Ceri-Wyn Thomas answered on 20 Jun 2010:

      Well finger and toenails are made of the same protein (keratin) as other mammals’ hooves and horns, so from an evolutionary perspective I guess we have retained that gene that causes the growth of those same horny coverings over the ends of our own limbs and that’s why we have them on our ‘front’ (hands) and ‘back’ limbs (feet). Primates also have nails.

      Fingernails are particularly useful to us. They offer some degree of protection from injury but they also help to increase the sensitivity of our finger tips since when we press down on an object our finger nails act as a kind of counter-force which prevents our fingertips from splaying out. This helps us to manipulate very delicate objects like tools (twigs and stones long ago, circuit boards and wires etc now!). Finally, fingernails also allow us to do really delicate things like picking thorns out of our skin or threading a needle- so they help us to manipulate our environment in quite fine detail. I guess toenails offer good protection although I doubt they’d help you thread a needle with your feet- unless you were really gifted! 😉

    • Photo: Bridget Waller

      Bridget Waller answered on 21 Jun 2010:

      Good question. They originated in the claws and functional ‘weapons’ and ‘tools’ we see in other mammals (look at your cats retractable claws – very cool), but now have shrunk to little coverings on our toes/finegrs. They probably still provide some protection from bruising, but not terribly functional on the whole.

    • Photo: Betul Arslan

      Betul Arslan answered on 22 Jun 2010:

      All animals together with homo sapiens have some sort of nails (like claws and talons). Our nails are like our tool to do things, can you imagine having no nail? That is how we ‘feel’ earth (and that is exactly why cats should not be declawed by the way) Our 30, 000 year old ancestors had nails too, they might not be crucial for living but they definitely had advantages in survival. Thanks for this intriguing question!

    • Photo: Maria Pawlowska

      Maria Pawlowska answered on 22 Jun 2010:

      Nothing much – they’re the evolutionary leftovers of hooves and claws 🙂

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