• Question: Why do we have hair on our heads?

    Asked by #nerdyweirdo to Chris, Josh, Rebecca, Rob, Susan on 23 Jun 2015.
    • Photo: Josh Meyers

      Josh Meyers answered on 23 Jun 2015:

      We have evolved to lose most of the hair on our bodies (compared with chimpanzees!) but it is thought that the hair on our heads remains for two main evolutionary reasons:
      1. To protect us from the sun’s damaging UV radiation which can cause sunburn and skin cancer.
      2. To help us maintain our body heat as much of this is lost through our heads. (There are some suggestions that this is not a biological effect, but an artefact of not usually wearing clothes on our heads – e.g. hats)

      There are also some other reasons we have hair:
      – Our eyebrows have evolved in order to keep sweat and other foreign particles out of our eyes. It could be that hair has a similar function.
      – Finally, nowadays humans are attracted to people with hair. So effectively we are breeding selectively to maintain hair in our population!

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