How do we measure life?

Cellularity is a design project that examines the social and technological impacts of being able to create life in the laboratory.

As a designer, I have collaborated with a team of UK researchers who are attempting to build artificial chemical cells that imitate selected properties of natural cells. As well as having potential technological applications, chemical cells could lead to a new understanding of how living and nonliving things differ from one another.

To explore these impacts, I have imagined how chemical cells could develop as a pharmaceutical technology and have designed The Cellularity Scale – a speculative definition of life that is applicable in a future where we no longer ask whether something is dead or alive, but instead, how alive it is.

The Emergence of Life in the Pharmaceutical Industry

This short film describes a scenario in which chemical cells are developed as a medical technology. The earliest generation of chemical cells are nothing more than a simple drug-delivery mechanism but successive generations accumulate more of the properties of natural cells until the fifth generation which is considered to be fully alive.

The Cellularity Scale

The Cellularity Scale is a speculative definition of life. It is an alternative to hard-edged definitions of life which are based on sets of essential properties. A living system, either natural or artificial, can be plotted on the scale between 0% (nonliving) and 100% (fully living).

Life-like properties

The scale is based on a gradual accumulation of living properties which are illustrated below.

14%

1. Individuation

The first true chemical cell approved for use in the healthcare industry is a simple construction approximately half the size of a red blood cell.

It is manufactured by forming an inorganic membrane around particles of a given drug compound.

30%

2. Metabolism

Advances in metabolic engineering led to the second generation of chemical cells.

When triggered, they are capable of manufacturing and releasing a specific drug as an when it is required.

50%

3. Replication

The third generation of chemical cells are equipped with the autocatalytic machinery necessary to replicate themselves.

Useful for treating chronic conditions, they maintain a constant population in a patient over extended periods of time.

72%

4. Reproduction

By reproducing in pairs, the fourth generation of chemical cells bear offspring that combine the metabolic processes of both their parents.

Often used when a patient’s condition does not respond to to a known compound, these offspring will produce novel varieties of drugs, some of which might have a positive effect.

100%

5. Death

The fifth and most recent generation of chemical cells are characterised by one important additional feature: the ability to die.

This makes them the subject to a form of natural selection, allowing them to evolve towards a more effective treatment of the patient’s condition.

A new tree of life

As well as being a method of measuring life, the scale can also be thought of as a root to a new tree of life.

Acknowledgments

This project was undertaken in collaboration with researchers on the Chell project:

• Prof. Cameron Alexander and Prof. Natalio Krasnogor at Nottingham University
• Prof. Lee Cronin at Glasgow University
• Prof. Ben Davis at Oxford University

Thanks to the following people for their advice and expertise:

• Jessica Bland at the Royal Society
• Geoff Cooper at the Cronin Lab
• John Dupré and Maureen O’Malley at Egenis
• Christophe Malaterre
• Tom Murray and Greg Kaebnik at the Hastings Center

The ideas in this project owe a debt to the following books and papers:

• The Imitation Game – A computational chemical approach to recognizing life by Leroy Cronin, Natalio Krasnogor, Benjamin G Davis, Cameron Alexander, Neil Robertson, Joachim H G Steinke, Sven L M Schroeder, Andrei N Khlobystov, Geoff Cooper, Paul M Gardner, Peter Siepman, Benjamin J Whitaker & Dan Marsh
• Lifeness signatures and the roots of the tree of life by Christophe Malaterre (forthcoming)
• What is Life? Investigating the Nature of Life in the Age of Synthetic Biology by Ed Regis