Evolution represents a natural experimental process for testing animal design features. Driven by environmental pressures, animals have evolved adaptations which can give valuable insights into human biomedical conditions. The giraffe by virtue of its extremely long neck has a mean arterial pressure much higher than other mammals. However, the giraffe does not develop vascular damage or heart failure despite its high mean arterial pressure. The giraffe's cardiovascular physiology challenges a number of current concepts concerning the genesis of hypertensive vascular damage in the human. All animals senesce, and, in general, the manifestations of this senescence are similar to the aging features observed in humans. The characteristics of aging in natural animals strongly suggest that the so-called chronic degenerative diseases of humans are not really diseases but actually manifestations of the aging phenotype. Glucose regulation in birds and the naked mole rat has features which mimic the characteristics of the diabetic state, yet these animals do not develop the complications occurring in humans with diabetes. Disruptions in the functioning of the circadian molecular clock are thought to underlie certain neuropsychiatric disorders. The honeybee and the zebrafish have emerged as natural animal models for studying the regulation of molecular clocks and the mechanisms underlying plasticity of circadian rhythms. These examples underscore the valuable insights that natural animals can furnish with respect to biomedical disorders. Yet, this information data base remains a largely untapped resource.