• Question: how do patterns on animals form?

    Asked by sophied to Adam, Catherine, Leila on 22 Mar 2012.
    • Photo: Adam Stevens

      Adam Stevens answered on 22 Mar 2012:

      Most patterns are different colours of hair (on mammals) or scales or other things (on other animals). The cells that make this hairs or scales will all have codes on that tell them to make a particular colour. Some of the cells will make one colour and some the other. How the pattern develops would have to be communicated from some kind of central controller. I don’t know if this would be the brain or if the cells just communciate between themselves.

      This property must have evolved over time as either camouflage or to make reproduction more likely – the animals with particular patterns (by random at first) either survive better, making their offspring slightly more patterned or are more likely to breed if their mates like their patterns (which would have been random at first as well!) making them more likely to have patterned offspring.

    • Photo: Leila Battison

      Leila Battison answered on 22 Mar 2012:

      Here’s another problem that scientists still don’t have complete answers to.

      Most patterns form on animals for camouflage (like cheeetahs), or as a warning (like snakes). The colour itself comes from certain pigments being ‘activated’ in the skin cells . But these cells are first made when the animal is a tiny embyro, so is one of the really early things to form, and we don’t know how the genes decide how to make the colour.

      Most animals can’t change their colours after they’ve been born (a leopard can’t change its spots!), but some animals, like octopuses and chameleons and some fish and jellyfish things, can change their colour really really quickly in response to the environment. Here, the amount of pigment can be changed according to what senses the brain recieves, creating new patterns.

      If you can, watch this video – I was amazed when I first saw it!

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