Skip to main content

Unit information: The Biology of Colour in 2021/22

Unit name The Biology of Colour
Unit code BIOL30014
Credit points 10
Level of study H/6
Teaching block(s) Teaching Block 4 (weeks 1-24)
Unit director Dr. How
Open unit status Not open

Recommended: Sensory Biology (Y2), Behavioural Ecology (Y2), Green Planet (Y2)



School/department School of Biological Sciences
Faculty Faculty of Life Sciences

Description including Unit Aims

Historically, the external appearance of organisms has been mainly of taxonomic or aesthetic interest to humans. Only recently has colouration been investigated from the standpoint of production, perception and function, tackling questions such as how and why colour patterns have evolved across nature, how do sensory systems detect and process this information, and how are colour patterns produced.

The forces that drive the evolution of colouration are diverse, including the need to communicate or to hide from others, the need to defend against the elements, and a variety of others that we are only just appreciating. A complete understanding of colouration involves quantifying colour, sensory limitations, and uncovering the diverse evolutionary forces shaping colouration in nature.

In this unit, we survey this rapidly developing field from these multiple perspectives, extending principles covered in second year units to understand issues as diverse as sexually selected ornamentation; colouration involved in anti-parasite and antipredator defence; leaf, fruit and flower colour; colouration as a deceptive mechanism; and the import of colour for humans in the sports arena. Throughout the unit we particularly emphasise the need to understand receiver sensory systems, comparative aspects of colouration in nature, and how methodology has been used to address the study of colouration.

While most units take a ‘field’ and study diverse topics within that field using similar methods, our unit takes a topic and studies it in radically different ways, promoting a recognised strength of the University of Bristol.

Intended Learning Outcomes

By the end of this unit, students will be able to:

1. Describe modes of colour production in the natural world;

2. Define how animals and plants sense light and describe the role of sensory systems in the evolution of colouration;

3. Describe and explain how signalling, protective colouration and environmental factors drive the evolution of colouration in animals and plants;

4. Illustrate how research methods can be applied at various spatial scales (ranging from photons to ecological networks) to study animal and plant colouration.

5. Evaluate the strength of evidence presented in scientific papers relevant to the theories of colouration.

6. Apply knowledge from the above, supported by examples from the literature, to propose novel hypotheses and experiments.

Teaching Information

Lectures, directed reading, research and/or problem-solving activities; and independent study.

Assessment Information

Summative written assessment, with one essay question to be selected from a choice of two.


If this unit has a Resource List, you will normally find a link to it in the Blackboard area for the unit. Sometimes there will be a separate link for each weekly topic.

If you are unable to access a list through Blackboard, you can also find it via the Resource Lists homepage. Search for the list by the unit name or code (e.g. BIOL30014).

How much time the unit requires
Each credit equates to 10 hours of total student input. For example a 20 credit unit will take you 200 hours of study to complete. Your total learning time is made up of contact time, directed learning tasks, independent learning and assessment activity.

See the Faculty workload statement relating to this unit for more information.

The Board of Examiners will consider all cases where students have failed or not completed the assessments required for credit. The Board considers each student's outcomes across all the units which contribute to each year's programme of study. If you have self-certificated your absence from an assessment, you will normally be required to complete it the next time it runs (this is usually in the next assessment period).
The Board of Examiners will take into account any extenuating circumstances and operates within the Regulations and Code of Practice for Taught Programmes.