The study of man's ills, diseases, diet, traumatic injuries, etc., by examination of human and animal remains. Such studies can determine life expectancy and population statistics, and contributory reason for the success or failure of a particular population. Most of the material studied is osteological, though soft tissue may be analyzed when preserved, as in of mummification or bog preservation. Some of man's ills - fractures, malnutrition, dental decay, and some diseases - leave their mark on his bones. Where his bones survive, evidence can be recovered which may reveal much about the conditions in which he lived, and died. Congenital malformations may show relationships between skeletons; diseases such as arthritis, tuberculosis, syphilis, and leprosy can be identified, as well as such conditions as bone fracture through injury. Evidence of war wounds and cannibalism have are also sought. The following groups of diseases have been regularly diagnosed in skeletons (both human and animals) from archaeological sites: (1) dental diseases; (2) diseases of the joints; (3) trauma (fractures and other injuries); (4) dietary deficiency diseases; (5) tumors; (6) inflammatory diseases: general inflammation and more specific conditions such as tuberculosis, leprosy and syphilis in man; (7) congenital deformities; and (8) endocrine disturbances. Study of the relative frequency of different diseases yields information about both the medical history and biology of ancient populations.