I try to read widely so I not only can plug my knowledge of genetics into the liberal arts, but into unconventional ways others see science. One recurrent theme, as old as the history of biology is the idea of holism. It is an outlook shared by those calling it vitalism, elan vital, enteleche, or mneme. More modern terms, like Gaia and systems theory, have been introduced in the last half of the twentieth century. They share a belief summed up in the popular phrase “the whole is greater than the sum of its parts.” Opposed to this outlook are a variety of terms used by scientists who oppose holism. They call themselves mechanists or reductionists or in an older terminology, positivists. What they share in common is a belief that the material (non-supernatural) world can be analyzed into its components by scientific methods using experimentation and new technologies. Their approach has given us the complex composition of atoms worked out by physicists, the combinatorial components of atoms in molecules worked out by chemists, the germ theory of disease, worked out by microbiologists, and the theory of the gene worked out by biologists.
The danger of reductionism in the life sciences, its opponents claim, is its tendency to oversimplify how life works or how traits and the intact organism are shaped. The danger of holism, its opponents claim, is its tendency to obscure explanation, substituting a fuzzy explanation or term for complex systems that are not fully resolved. Reductionist virologists claim they not only can take apart viruses into their protein and nucleic components, but reconstitute the viruses from these components, or more remarkable, they can use “off the shelf chemicals” to synthesize the proteins and nucleic acid of a virus and make a live infectious virus from it as has been done for polio. The debate becomes polemic on both sides when human behavioral traits or human health issues are studied. Holistic thinkers properly condemn what they call genetic determinism for social traits like pauperism, criminality, psychosis, mental retardation, or inappropriate personalities. They invoke the abuses of the eugenic movements which tried to tie these social failings to Mendelian genes. The science of that social movement was sloppy and repudiated by many geneticists. Some genetic determinists today invoke molecular lesions in alleged genes for these traits. The media tend to report alleged genes for alcoholism, criminality, phobias, belief in God, altruism, selfishness, territoriality, sexism, and racism. They rarely report in the same detail follow-up reports that fail to confirm such alleged genetic determinants.
Most puzzling to me is how to interpret holistic interpretations of life. There is no doubt things are complex. Cells are complex. Organisms are complex. Ecological systems are complex. Cell biologists have worked out functions for many cell organelles. While viruses can be synthesized from simple chemicals, bacteria or nucleated cells cannot with today’s available techniques and knowledge. I would prefer acknowledging what we do not know than trying to create an alternative holistic explanation that tells us little about the processes involved. How does such an explanation differ from invoking a homunculus in each living cell? We could call it a “cellular soul” that regulates the dance or symphonic coordination, or multiple systems moving back and forth from the environment to the genes, changing them in subtle ways. How can this be so plastic if we look at the physical bodies of identical twins throughout their lives from birth to death? They are usually strikingly similar. But in behavior, occupation, or personality, they can be quite different. Doesn’t this tell us that the physical body is more fully controlled by the functioning of our genes? In contrast, does this not tell us that most social or behavioral traits are controlled chiefly by upbringing and culture?