However, the notion of the Primacy of DNA has been soundly challenged by current research which reveals that the existence of a self-regulatory property for genes is a patently incorrect assumption. An important article by H. F. Nijhout (Metaphors and the Role of Genes in Development, BioEssays 12:441, 1990) describes how concepts concerning genetic “controls” and “programs” were originally conceived as a metaphor to help define and direct avenues of research. Widespread repetition of this compelling hypothesis over time has resulted in the “metaphor of the model” becoming the “truth of the mechanism,” despite the absence of substantiative supporting evidence.

Nijhout elegantly and succinctly redefined the truth as follows, “When a gene product is needed, a signal from its environment, not a self-emergent property of the gene itself, activates expression of that gene (emphasis mine).” Simply stated, a gene can not turn itself on or off, it is dependent upon a signal from its environment to control its expression. Genes are indeed involved with the structure and behavior of an organism, however they are not the source of “control.”

Gene expression is under the influence of specialized proteins referred to as regulatory proteins. Regulatory proteins bind to DNA and mask the activity of genes. In order to activate a specific gene, its regulatory proteins must be removed from the DNA strand. The binding and release of DNA regulatory proteins is controlled by “environmental” signals. Rather than recognizing the Primacy of DNA, it is more correct to acknowledge the Primacy of the Environment as causal in shaping biological expression.

The fact that the cell’s nucleus and its enclosed genes do not represent the controlling element or “brain” of the cell is easily verified in studies wherein the cell is structurally or functionally enucleated. Cells in such experiments continue to express complex behavioral repertoires and purposeful interactions with their environment and may survive for months despite the absence of functional genes. Consequently, genes can not be invoked to be the source of “control” in regulating cell behavior.

Even though genes are not self-regulating, they do encode the characteristics of our physical body. All of our genes are derived from parental DNA, therefore it could still be argued that our expression (physiology, health, behavior) is “predetermined” by our genetic heritage. Even that assumption has now gone by the wayside. In 1988, geneticist John Cairns published what has since become a revolutionary paper entitled On the Origin Of Mutants (Nature 335:142, 1988). Cairns recognized that gene mutations were not solely the result of random chemical events as is currently perceived.