Throughout the continuum of medical and scientific history, repeated evidence has confirmed that the main etiological determinants of disease are nutritional deficiency, toxicant exposures, genetic predisposition, infectious agents, and psychological dysfunction. Contemporary conventional medicine generally operates within a genetic predestination paradigm, attributing most chronic and degenerative illness to genomic factors, while incorporating pathogens and psychological disorder in specific situations. Toxicity and deficiency states often receive insufficient attention as common source causes of chronic disease in the developed world. Recent scientific evidence in health disciplines including molecular medicine, epigenetics, and environmental health sciences, however, reveal ineluctable evidence that deficiency and toxicity states feature prominently as common etiological determinants of contemporary ill-health. Incorporating evidence from historical and emerging science, it is evident that a reevaluation of conventional wisdom on the current construct of disease origins should be considered and that new knowledge should receive expeditious translation into clinical strategies for disease management and health promotion. An analysis of almost any scientific problem leads automatically to a study of its history.--Ernst Mayr.