• Question: Why do people have different coloured skin?

    Asked by Afaf to Carolyn, Peter, Richard, Sara, Siana on 17 Nov 2015.
    • Photo: Richard Unwin

      Richard Unwin answered on 17 Nov 2015:

      Hi Afaf,
      Good question. The colour of your skin is controlled by the amount of a pigment called melanin you make, and this is controlled by your genes. Melanin acts to protect the skin from sunlight, so you’ll find that people whose families came from hot countries e.g. Africa have genes that help them make more melanin, so their skin is darker. People with ancestors from cold countries don’t need that melanin, so have genes for less melanin giving them lighter coloured skin. These genes are turned on by sunlight, which is why light skinned people tan in the sun.

    • Photo: Carolyn Nielsen

      Carolyn Nielsen answered on 17 Nov 2015:

      Great answer by Richard.

      There’s also an interesting condition called vitiligo, where pigment is lost from patches of the skin because of a lack of melanin in those areas. It’s not completely clear why this happens, but it is likely related to a malfunction with the immune system that causes it to mistakenly attack part of the body (autoimmunity).

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