Paleopathology

Paleopathology is the study of the evidence of trauma, disease, and congenital defects in human remains. Archaeologists, geneticists, and physical anthropologists, conduct paleopathology studies in order to evaluate the effects of disease upon ancient populations. Often, such research is conducted to garner more information about the biological and genetic characteristics of prehistoric or ancient populations, but sometimes paleopathology involves scientifically evaluating accounts of epidemics in historical records.

The earliest form of the science of paleopathology emerged in the 1600s. German naturalists, interested in newly discovered Egyptian mummies, carefully dissected and inspected the bones and tissues of specimen and attempted to compare the remains with contemporary cadavers. Early paleopathologists were able to identify striations and lesions on bone that indicated arthritis. In the late 1700s, scientists also cataloged distinctive marks on bone and tooth remains that were the result of deadly fevers.

Modern paleopathology is not limited to the study of mummified corpses. Various other types of remains, such as bone, teeth, blood, hair, fingerprints, and human waste, are actually utilized more frequently in research. As medical technology has become more advanced, scientists have been able to conduct paleopathological analysis on smaller amounts of biological material. With the aid of technology such as CAT scans and fiber optics, scientists are able to extract sample material without need of autopsy, thereby leaving remains relatively undisturbed and intact for future study.

The most common application of paleopathology is in studying patterns of disease in ancient individuals and populations. Osteologists (scientists who study bone remains) in the United States have devoted considerable effort to the study of the effects of European diseases on Native American population during the early colonial period (1492–1650). Analysis of remains not only shows the effect of disease upon individual specimen, but also adds to a larger understanding of the modes of transmission, virility, and mortality rates associated with epidemics. Paleopathology can also be used in combination with some forms of population genetics. For example, comparisons of analyzed remains from diverse geographic regions or kin associations assists in distinguishing possible genetic traits that aid in a population’s resistance to certain diseases.

Paleopathology is one of the few means scientists have at their disposal to gain clues about the diet, health, pathology, and general genetic trends of ancient populations. Scientists also use paleopathology as a means of collecting “census material” or information regarding a specimen’s age, sex, stature, and cause of death. From this data, anthropologists can estimate the general demographic composition of populations without the benefit of sometimes confused, scattered, fragmentary, or inaccurate written records. Even information about social customs and medicinal practices can sometimes be determined thorough paleopathological research on human materials. For example, skulls found in South America suggest that ancient peoples may have attempted to perform a primitive type of neurosurgery to relieve fevers or brain swelling. High levels of arsenic and mercury in hair samples from Medieval remains in France have raised questions about water contamination or possible medicinal use.

There are several limitations to paleopathological research. Since skeletal material is the most frequently recovered type of human remain, most paleopathology studies pertain to diseases that visibly alter or affect bone. Many diseases affect bone in similar ways, thus making it difficult and sometimes impossible to determine the exact disease represented. Many diseases do not affect bone at all, and are only evident in tissue, hair, or other rare remains. Paleopathology currently accounts for only a portion of the total diseases that ravaged past populations.

These very limitations, however, have yielded a paradoxical wealth of information. In the case of the disease tuberculosis, the limitations of paleopathology have provided a narrow scientific framework in which to study the disease without worry that data will grossly over-represent its threats and effects. Scientists know that tuberculosis remained a constant threat throughout the historic period until the advent of antibiotics and vaccines. Mentions of tuberculosis and tuberculin symptoms are present in medical writings from Ancient Greece and China, and the disease was still the focus of public health commissions at beginning of the twentieth century. However, tuberculosis is primarily a disease of the lungs, and only affects the skeletal system in 5–7% of all infected persons. Given the infrequency of bone degeneration associated with the disease, and the given limitations of paleopathological research itself, scientists did not expect to find numerous remains with evidence of tuberculosis. Yet, such remains have been discovered on every continent, in both prehistoric and historic burials, at a relatively frequent rate. Paleopathologists have concluded two possibilities. The first possibility is that the tuberculosis bacillus itself has altered and now produces a different pathological signature (e.g. that it used to affect bone more frequently) or that a certain strain was once more prevalent. The second possibility is that the disease was more widespread than scientists had previously estimated. Many paleopathologists theorize that both possibilities are factors in the history of tuberculosis.

The context of paleopathological research is not limited to the ancient world. However, modern research of this type often falls under the label of forensic anthropology—the branch of science most popularly known for its applications in crime investigation.

See also Archaeogenetics.