How do animals change their colour? | The Economist
- 5 years ago
Take a look at the science behind the kaleidoscopic animals that can adopt new colours at will.
Click here to subscribe to The Economist on YouTube: http://econ.trib.al/rWl91R7
Chameleons aren't the only animals that can change colour. Some primates can blush. How do animals change colour?
1. Brain signals:
The colours of the environment, a rival, or mate, trigger a signal from the brain to other cells. In some animals the process starts in the eye, called chromatophores. Chromatophores are packed in their thousands beneath the skin surface. Some of these cells contain sacs of colour pigments. Muscles in the skin adjust the size and position of these sacs. This changes their colour.
2. Trick of the light:
Other creatures use optical trickery in cells called iridophores. Iridophores are skin cells containing micro-crystals. The spacing between these tiny crystals determines the light reflected. Chameleons have two layers of iridophores. They switch their colour from green to red by changing the spaces between these crystal layers.
In humans, colour change is simpler. Blushing is a rush of blood to the face where blood vessels are close to the skin's surface. A red flush is often involuntary but its biological purpose remains a matter of debate.
Daily Watch: mind-stretching short films every day of the working week.
For more from Economist Films visit: http://films.economist.com/
Check out The Economist’s full video catalogue: http://econ.st/20IehQk
Like The Economist on Facebook: https://www.facebook.com/TheEconomist/
Follow The Economist on Twitter: https://twitter.com/theeconomist
Follow us on Instagram: https://www.instagram.com/theeconomist/
Follow us on LINE: http://econ.st/1WXkOo6
Follow us on Medium: https://medium.com/@the_economist
Click here to subscribe to The Economist on YouTube: http://econ.trib.al/rWl91R7
Chameleons aren't the only animals that can change colour. Some primates can blush. How do animals change colour?
1. Brain signals:
The colours of the environment, a rival, or mate, trigger a signal from the brain to other cells. In some animals the process starts in the eye, called chromatophores. Chromatophores are packed in their thousands beneath the skin surface. Some of these cells contain sacs of colour pigments. Muscles in the skin adjust the size and position of these sacs. This changes their colour.
2. Trick of the light:
Other creatures use optical trickery in cells called iridophores. Iridophores are skin cells containing micro-crystals. The spacing between these tiny crystals determines the light reflected. Chameleons have two layers of iridophores. They switch their colour from green to red by changing the spaces between these crystal layers.
In humans, colour change is simpler. Blushing is a rush of blood to the face where blood vessels are close to the skin's surface. A red flush is often involuntary but its biological purpose remains a matter of debate.
Daily Watch: mind-stretching short films every day of the working week.
For more from Economist Films visit: http://films.economist.com/
Check out The Economist’s full video catalogue: http://econ.st/20IehQk
Like The Economist on Facebook: https://www.facebook.com/TheEconomist/
Follow The Economist on Twitter: https://twitter.com/theeconomist
Follow us on Instagram: https://www.instagram.com/theeconomist/
Follow us on LINE: http://econ.st/1WXkOo6
Follow us on Medium: https://medium.com/@the_economist