Unmitigated reductionism has had a detrimental effect on drug discovery and vaccine development
We simply can’t anticipate or compute some interactions and effects due to the sheer complexity of living organisms in thermodynamic interaction with their environment. For instance, the experience of pain can alter human behaviour, but the lower-level chemical reactions in the neurons that are involved in the perception of pain are not the cause of the altered behaviour, as the pain itself has causal efficacy. According to the principles of emergence, the natural world is divided into hierarchies that have evolved over evolutionary time (Kim, 1999; Morowitz, 2002). Reductionists advocate the idea of ‘upward causation’ by which molecular states bring about higher-level phenomena, whereas proponents of emergence accept ‘downward causation’ by which higher-level systems influence lower-level configurations (Kim, 1999).
The constituents of a complex system interact in many ways, including negative feedback and feed-forward control, which lead to dynamic features that cannot be predicted satisfactorily by linear mathematical models that disregard cooperativity and non-additive effects...
An additional peculiarity of complex biological systems is that they are open—that is, they exchange matter and energy with their environment—and are therefore not in thermodynamic equilibrium...
In the past, the reductionist agenda of molecular biologists has made them turn a blind eye to emergence, complexity and robustness, which has had a profound influence on biological and biomedical research during the past 50 years.
The number of new drugs that are approved by the US Food and Drug Administration has declined steadily from more than 50 drugs per annum 10 years ago to less than 20 drugs in 2002. This worrying trend has persisted despite continuous mergers and acquisitions in the industry and annual research and development expenditures of approximately US$30 billion. Commentators have attributed this poor performance to a range of institutional causes . . . However, there is probably a more fundamental reason for these failures: namely, that most of these approaches have been guided by unmitigated reductionism. As a result, the complexity of biological systems, whole organisms and patients tends to be underrated (Horrobin, 2001). Most human diseases result from the interaction of many gene products, and we rarely know all of the genes and gene products that are involved in a particular biological function. Nevertheless, to achieve an understanding of complex genetic networks, biologists tend to rely on experiments that involve single gene deletions. Knockout experiments in mice, in which a gene that is considered to be essential is inactivated or removed, are widely used to infer the role of individual genes. In many such experiments, the knockout is found to have no effect whatsoever, despite the fact that the gene encodes a protein that is believed to be essential. In other cases, the knockout has a completely unexpected effect (Morange, 2001a). Furthermore, disruption of the same gene can have diverse effects in different strains of mice (Pearson, 2002). Such findings question the wisdom of extrapolating data that are obtained in mice to other species. In fact, there is little reason to assume that experiments with genetically modified mice will necessarily provide insights into the complex gene interactions that occur in humans (Horrobin, 2003).
Another defect of reductionist thinking is that it analyses complex network interactions in terms of simple causal chains and mechanistic models. This overlooks the fact that any clinical state is the end result of many biochemical pathways and networks, and fails to appreciate that diseases result from alterations to complex systems of homeostasis. Reductionists favour causal explanations that give undue explanatory weight to a single factor.
Unmitigated reductionism has had a detrimental effect on drug discovery and vaccine development
We simply can’t anticipate or compute some interactions and effects due to the sheer complexity of living organisms in thermodynamic interaction with their environment. For instance, the experience of pain can alter human behaviour, but the lower-level chemical reactions in the neurons that are involved in the perception of pain are not the cause of the altered behaviour, as the pain itself has causal efficacy. According to the principles of emergence, the natural world is divided into hierarchies that have evolved over evolutionary time (Kim, 1999; Morowitz, 2002). Reductionists advocate the idea of ‘upward causation’ by which molecular states bring about higher-level phenomena, whereas proponents of emergence accept ‘downward causation’ by which higher-level systems influence lower-level configurations (Kim, 1999).
Have a read:
Reductionism and complexity in molecular biology
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1299179/
Some highlights