Human illnesses can be understood as damage to those adaptations that we took on at various stages in our evolution from pre-life molecules to modern Homo sapiens. Preventing these illnesses entails avoiding what causes the damage-- which too frequently are the everyday hazards of twenty-first-century life, as the chart below shows: Level of EvolutionCause of adaptive failureresulting disease or problemPre-lifeEnvironmental poisonsCertain birth defectsSingle cell (bacteria and amoeba-like)Viral infectionColds/flu/HIVMorula (sponge-like)Cellular stressCancerChordatePhysical stressBack painFishExcess dietary saltHypertension/heart diseaseAmphibianTobacco smokeLung cancer/emphysemaLower primateExcess dietary sugarDiabetes mellitusHigher primateVitamin C deficiencyScurvyApeExcess dietary proteinGoutHomo sapiensReduced dietary varietyNutritionaldiseases/food allergies