Women in Science: Unexpected aliens

TM & copyright 20th Century Fox/Rex Features

For those of you who have watched James Cameron’s Avatar, if you cast your mind back you might remember that in this film a well-informed fantastical ecology was created, with many of its constituent animals and plants showing utterly alien traits, such as six-legged elephant-horses, and bizarre iridescent blue plants.

Except, iridescent blue plants aren’t in the least bit alien. There are many plant species that produce a vivid metallic blue iridescence. Even in the UK we have these strange looking organisms, though you would have to wade into the sea to see them, as it is really only some native seaweeds (such as Drachiella spectabilis) that show any iridescence in our temperate climate. However, in many tropical rain forests, vivid metallic blue ferns, spike mosses, orchids and begonias can be found hiding in the undergrowth. Although they are not always immediately obvious, when the dark conditions in which they grow are illuminated by a sudden speck of sunlight, the colours that these plants reflect can rival in intensity and beauty the iridescence found in any butterfly or bird.

While these iridescent plants are not alien, they are however still a bit of a mystery. By and large plants are green, and this is no bad thing as chlorophyll  (the molecule responsible for producing the green colour) is the vital component in photosynthesis, the reaction that is ultimately responsible for everything that plants produce – from tea, chocolate, aspirin and corn to oxygen – in general everything that is needed for our continued survival. A few plants, such as the British native Toothwort, do not produce chlorophyll at all, and resort to parasitizing green plants. They can be easily identified as the strange ghostly-white plants growing under trees like Hazel whose roots they have infested.

So why would these iridescent plants buck the trend and resort to being not just blue, but such a vivid metallic blue? I don’t know, and (this might sound strange) I am actually really glad I don’t know, because I now have the opportunity to try and discover the answer. For me, it is an intriguing study because these blue plants really should not be this colour. Blue light is vital to plant growth, as it tells the plant where light is coming from. When a house plant bends towards a window, it is the blue light from the window that has given the plant with this information. By producing iridescence that reflects this blue light, the plant is not only missing out on energy for photosynthesis, but could also be missing out on useful information about its surroundings. But not only are the plants blue, this strange iridescence has evolved repeatedly throughout the evolution of plants. This suggests that in some conditions, producing this iridescence has a real advantage that helps the plant survive.

While the benefit of looking at bizarre phenomena such as iridescence in plants might not be immediately obvious, a new term – biomimetics – has been coined that describes where research like this can sometimes lead, where biological systems are used as the source of inspiration for design and engineering. The classic (and one of the earliest recorded) example of plant-inspired biomimetics is Velcro, after the Swiss engineer George de Mestral found how well the burrs of burdock attached to his dog’s (and his own) coat. Current attempts to increase the efficiency of solar panels are inspired by plants and their abilities to harvest sunlight in diverse and often difficult conditions. The self-cleaning surfaces now being advertised for glass and other surfaces were originally inspired by the leaves of the Sacred Lotus, the leaves of which are always spotless regardless of the boggy conditions in which it grows. This list could go on, and is continually being added to as the diverse strategies that plants use to survive in hostile conditions that they can’t run from are translated into new ideas to improve our lives. So while I am not sure if the iridescence found in tropical plants was in any way a source of the alien colours found in the science fiction ecology of Avatar, I am convinced that plants will continue to provide inspiration for new ideas in the future.

Dr Heather Whitney is speaking at ZSL and L’Oréal-UNESCO’s Soapbox Science on Southbank, 16th July 2012 www.zsl.org/soapboxscience

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• http://www.facebook.com/GerryTierney Gerald Joseph Tierney

  What I wanted to know about Avatar is why aliens who aren’t placental mammals have breasts.

• rongraves

  But they were – they also had navels, confirming this.

• http://www.facebook.com/philip.feeley.3 Philip Feeley

  Does anyone know of any other articles or books describing the materials we’ve developed like those in their last chapter? This would be an interesting (and optimistic) read.

• http://www.facebook.com/GerryTierney Gerald Joseph Tierney

  No, it was just another innacuracy.