• Question: why are your fingernails the colour that they are?

    Asked by claireandhannah to Iain, Jo, Leo, Mariam on 23 Jun 2010 in Categories: . This question was also asked by kannah.
    • Photo: Iain Moal

      Iain Moal answered on 23 Jun 2010:

      Well, they should be see-thorough, unless you use nail varnish, in which case you know why they are the colour they are 🙂

      Fingernails are made of a protein called keratin, which is colourless, so that is why they are the way they are.

    • Photo: Leo Garcia

      Leo Garcia answered on 23 Jun 2010:

      Well, I can probably answer HOW they are as they are, but not necessarily WHY. Although, for the WHY questions in biology, we must always look towards our evolution.

      For how, then: Nails are made from a strong protein called ‘keratin’, which is the same thing that hair and, in other animals, hooves and horns are made of. The part of the nail we see (as some of it is embedded under the skin of our fingers), is known as the ‘nail plate’, and is translucent. So, the ‘colour’ we see is actually the colour of the underlying capillaries.

      For why the nail plate is see through – well, I suppose a good question to answer is ‘why shouldn’t they be?’ If there is no evolutionary pressure towards nail plates which are, say, black, or striped etc. then it is more efficient for the body not to have to spend energy on making unecessary pigment!

    • Photo: Joanna Watson

      Joanna Watson answered on 23 Jun 2010:

      I don’t know, I guess they could be a different colour because I think they are made out of the same stuff as horses hooves and dogs claws (I’m not 100% sure about that) and they can be different colours.