The biology of colour
Press release issued: 9 August 2017
Colouration is a vitally important biological trait because it is involved in individual survival and with reproduction through camouflage, warning colouration, mate choice, social signalling, thwarting parasitism, as well as thermoregulation.
In a wide-ranging and comprehensive review, published in Science last week, a group of evolutionary biologists, behavioural ecologists, psychologists, optical physicists, visual physiologists, geneticists and anthropologists – including academics from the University of Bristol – turn their attention to this diverse area of science and set out what they believe are the key questions for the future.
In the last 20 years, the field of animal colouration research has been propelled forward very rapidly by technological advances. These include spectrophotometry, digital imaging, innovative laboratory and field studies, and large scale comparative analyses each of which are allowing completely new questions to be asked.
For example, we now recognise that other organisms see the world differently from humans.
We understand the mechanisms underlying of colour production, and studies of function have advanced through elegant field and lab experiments. Interspecific colour measurements collected at a geographic scale are even shedding light on the dynamics of evolutionary processes.
We can now pose questions about the evolution of camouflage based on what a prey’s main predator can see. We can start to appreciate that gene changes underlying colour production have occurred in parallel in unrelated species. Knowledge of production and perception and function of colouration is poised to make contributions to medicine, security, clothing and the military.
Dr Laszlo Talas, member of University of Bristol’s Camo Lab and one of the co-authors said: "Because we often adopt a human-centric view when thinking about the colours of animals and their ecology, it can lead to fallacies.
"Most animals did not evolve to hide from us. We must recognise the differences in visual ecology across the animal kingdom. For example, while we can easily spot the light brown coats of West Caucasian turs (a goat-like animal) against green vegetation, a lynx, their main predator, has dichromatic colour vision with poorer acuity and it would not be able to see them so clearly.
"This is just one of many examples we should keep in mind when trying to make sense of animal camouflage."
The review stems from a workshop held at the Wissenschaftskolleg zu Berlin (Institute of Advanced Studies, Berlin), organised by Tim Caro (University of California Davis, USA) and Innes Cuthill (University of Bristol). This meeting also spawned a special edition of Philosophical Transactions of the Royal Society published last month, featuring 19 more specialized articles on animal colouration: http://rstb.royalsocietypublishing.org/content/372/1724
‘The biology of colour’ by I. Cuthill, W. Allen, K. Arbuckle, B. Caspers, G. Chaplin et al in Science.