LETTERS TO THE EDITORS
Dogs, Genes and Drugs
To the Editors:
The article "Genetics and the Shape of Dogs" by Elaine A. Ostrander (September-October) was excellent, in addition to being a good example of how the same genetic makeup can give rise to different characteristics. The theme of the article raises questions about using animals to predict drug and disease response in humans.
All animals are examples of robust, complex systems (on many levels) and hence have emergent, modular and nonlinear properties. Perturbations in one complex system that lead to an effect will not necessarily lead to the same effect in a different complex system, regardless of how similar the two systems are or were.
Living complex systems also manifest different responses to the same stimuli because of differences in genes, mutations in the same gene, differences in proteins, gene regulation, gene expression, protein-protein interactions, gene networks or environmental exposures.
Therefore, we now understand why even two nearly identical complex systems (for example, a chimpanzee and a human, or even monozygotic twins) may respond differently to drugs and experience different diseases, and hence why one complex system/species cannot reliably predict responses for a different complex system/species.
Current biomedical research is studying disease and drug response at the level where the differences between complex systems (be they two different species or two different humans) become momentous, hence using animals to predict human response to disease and drugs is scientifically questionable.
Americans For Medical Advancement
Los Angeles, CA