Human illnesses can be understood as damage to those adaptationsthat we took on at various stages in our evolution from pre-lifemolecules to modern Homo sapiens. Preventing these illnessesentails avoiding what causes the damage-- which too frequently arethe everyday hazards of twenty-first-century life, as the chartbelow shows br br Level of Evolutionbr br Cause of adaptive failurebr br resulting disease or problembr br Pre-lifebr br Environmental poisonsbr br Certain birth defectsbr br Single cell bacteria and amoeba-likebr br Viral infectionbr br ColdsfluHIVbr br Morula sponge-likebr br Cellular stressbr br Cancerbr br Chordatebr br Physical stressbr br Back painbr br Fishbr br Excess dietary saltbr br Hypertensionheart diseasebr br Amphibianbr br Tobacco smokebr br Lung canceremphysemabr br Lower primatebr br Excess dietary sugarbr br Diabetes mellitusbr br Higher primatebr br Vitamin C deficiencybr br Scurvybr br Apebr br Excess dietary proteinbr br Goutbr br Homo sapiensbr br Redu