• Question: why are some people short and some people tall?

    Asked by Botha to Aimee, Gemma, Hussain, Robert, Ross on 9 Nov 2015.
    • Photo: Ross King

      Ross King answered on 9 Nov 2015:

      This is a fantastic question – what makes us short and what makes us tall is an incredibly complicated thing! It’s all down to what’s in our DNA, the building blocks of our genetic code, which also controls many other things, such as what colour our eyes will be.

      Some of our features are controlled by one single patch of DNA, like colour blindness. Most other things are more complicated, and are controlled by lots of different patches of DNA.

      Some scientists say that about 400 different patches of DNA can work together to tell our bodies how tall we’ll grow. Any changes in these patches of DNA (that we call ‘mutations’) can increase the chance of you being taller, or shorter. We all have different DNA so this means we’re all different sizes.

      Sometimes, things that happen to us in our environment can control how tall or short we’ll be. For example, babies who have mothers who smoke have a higher chance of being shorter, rather than taller.

    • Photo: Hussain Jaffery

      Hussain Jaffery answered on 9 Nov 2015:

      This is probably one of the hardest questions in biology. We don’t know the complete answer to it, but we do know that at least 100 different genes determine height! Lots of different things have to work together to make you tall or short. Because people are so different and diverse, especially at the DNA level, we se lots of heights.

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