From an evolutionary point of view, most complex chronic diseases appear to be the result of imbalance, mismatch, between our genetic makeup and the conditions of life in Westernized twenty-first century nations. The basic contentions (Eaton and Eaton, 1999a; Eaton et al., 2002a) are that:

1. The contemporary human genome was selected over thousands of millennia during which our ancestral line existed as prehuman primates who became increasingly human-like until, during the period between 100 and 50 thousand years ago, they became behaviorly modern and lived as near equivalents of hunter-gatherers studied during the last century.

2. Our genetic makeup, especially that regarding our core metabolic and physiologic characteristics, has changed very little between the emergence of agriculture, roughly 10 000 years ago, and the present.

3. On the other hand, cultural change during these past 10 millennia has progressed at an ever-accelerating rate. The resulting dissonance between what amount to Stone Age genes and Space Age lives fosters development of multiple health disorders ranging from the potentially life threatening (cancer, pulmonary emphysema, heart attacks) to the more mundane, but still costly and uncomfortable conditions such as acne, high frequency hearing loss, myopia (near sightedness), and dental caries.

These contentions make up the “discordance hypothesis” and its corollary is that the “afflictions of affluence” might best be prevented by reincorporating the essentials of our ancestral living pattern into our contemporary lives – ideally blending the best from the past with best from the present.