Tag Archives: biological diversity

Reduction in usefulness of reductionism

decorative paintingA couple of months ago I wrote about a set of credibility factors for computational models [see ‘Credible predictions for regulatory decision-making‘ on December 9th, 2020] that we designed to inform interactions between researchers, model builders and decision-makers that will establish trust in the predictions from computational models [1].  This is important because computational modelling is becoming ubiquitous in the development of everything from automobiles and power stations to drugs and vaccines which inevitably leads to its use in supporting regulatory applications.  However, there is another motivation underpinning our work which is that the systems being modelled are becoming increasingly complex with the likelihood that they will exhibit emergent behaviour [see ‘Emergent properties‘ on September 16th, 2015] and this makes it increasingly unlikely that a reductionist approach to establishing model credibility will be successful [2].  The reductionist approach to science, which was pioneered by Descartes and Newton, has served science well for hundreds of years and is based on the concept that everything about a complex system can be understood by reducing it to the smallest constituent part.  It is the method of analysis that underpins almost everything you learn as an undergraduate engineer or physicist. However, reductionism loses its power when a system is more than the sum of its parts, i.e., when it exhibits emergent behaviour.  Our approach to establishing model credibility is more holistic than traditional methods.  This seems appropriate when modelling complex systems for which a complete knowledge of the relationships and patterns of behaviour may not be attainable, e.g., when unexpected or unexplainable emergent behaviour occurs [3].  The hegemony of reductionism in science made us nervous about writing about its short-comings four years ago when we first published our ideas about model credibility [2].  So, I was pleased to see a paper published last year [4] that identified five fundamental properties of biology that weaken the power of reductionism, namely (1) biological variation is widespread and persistent, (2) biological systems are relentlessly nonlinear, (3) biological systems contain redundancy, (4) biology consists of multiple systems interacting across different time and spatial scales, and (5) biological properties are emergent.  Many engineered systems possess all five of these fundamental properties – you just to need to look at them from the appropriate perspective, for example, through a microscope to see the variation in microstructure of a mass-produced part.  Hence, in the future, there will need to be an increasing emphasis on holistic approaches and systems thinking in both the education and practices of engineers as well as biologists.

For more on emergence in computational modelling see Manuel Delanda Philosophy and Simulation: The Emergence of Synthetic Reason, Continuum, London, 2011. And, for more systems thinking see Fritjof Capra and Luigi Luisi, The Systems View of Life: A Unifying Vision, Cambridge University Press, 2014.


[1] Patterson EA, Whelan MP & Worth A, The role of validation in establishing the scientific credibility of predictive toxicology approaches intended for regulatory application, Computational Toxicology, 17: 100144, 2021.

[2] Patterson EA &Whelan MP, A framework to establish credibility of computational models in biology. Progress in biophysics and molecular biology, 129: 13-19, 2017.

[3] Patterson EA & Whelan MP, On the validation of variable fidelity multi-physics simulations, J. Sound & Vibration, 448:247-258, 2019.

[4] Pruett WA, Clemmer JS & Hester RL, Physiological Modeling and Simulation—Validation, Credibility, and Application. Annual Review of Biomedical Engineering, 22:185-206, 2020.

Where have all the insects gone?

I remember when our children were younger, and we went on our summer holidays by car, that the car windscreen would be splattered with the remains of dead insects.  This summer my wife and I drove to Cornwall and back for our holidays almost without a single insect hitting our windscreen.  Where have all of the insects gone?  It would appear that we, the human species, have wiped them out as a consequence of the way we exploit the planet for our own comfort and convenience.  Insecticides and monocultures aided by genetically-modified crops make a direct contribution but our consumption of fossil fuels and intensive production of everything from beef [see ‘A startling result‘ on May 18th, 2016] to plastics is changing the environment [see ‘Productive cheating?‘ on November 27th, 2013]. The biologist, Edward O. Wilson observed that ‘If all humankind were to disappear, the world would regenerate back to the rich state of equilibrium that existed 10,000 years ago. If insects were to vanish, the environment would collapse into chaos.’  It looks like we are on the cusp of that collapse.

Cristiana Pașca Palmer, the executive secretary of the UN Convention on Biological Diversity has highlighted the impact of our actions as a species on the other species with which we share this planet.  We are making the planet uninhabitable for an increasing number of species to the extent that the rate of extinct is perhaps the fastest ever seen and we might be the first species to catalogue its own demise.  Our politicians have demonstrated their inability to act together over climate change even when it leads to national disasters in many countries; so, it seems unlikely that they will agree on significant actions to arrest the loss of bio-diversity.  We need to act as individuals, in whatever way we can, to reduce our ecological footprints – that impact that we have on the environment [see ‘New Year Resolution‘ on December 31st, 2014] .  As the Roman poet Horace wrote: ‘You are also affected when your neighbour’s house is on fire’; so, we should not think that none of this affect us.

See also:

Man, the Rubbish Maker

Are we all free-riders?