Reading the bones.

THE MODERN ERA OF DISEASE EMERGENCE AND REEMERGENCE IS ATTRIBUTED TO ISSUES RANGING from the deterioration of the environment, which brings humans in contact with pathogens that jump species barriers, to globalization, which is expanding the reach of pathogens beyond their former geographic boundaries. The transition from foraging to agriculture about 10,000 years ago accelerated the emergence of infectious disease. But it was the rise in social inequalities within and between societies that created disparities in disease risks and access to treatments, conditions that are still evident in today’s world. The calls for improving surveillance, research, vaccines, and behavioral change are indeed urgent, but what is also worrisome is the lack of an evolutionary perspective in formulating new strategies to confront this modern disease-scape. Paleopathology—the study of ancient diseases—not only provides an archaeological record of the adaptations and lifeways of ancient peoples, it is a source of information on the evolutionary epidemiology of infectious diseases. Reading the bones of the ancient dead can guide how we confront infectious diseases today. The genomic analysis of pathogens in human remains, together with knowledge from oral history and tradition, provides a framework for understanding the emergence of modern diseases. As described in the News story on p. 1306, analysis of the graveyard of the Abbey of St. Peter in the province of Lucca, Italy, is revealing how epidemics such as the plague spread through Europe. It was once thought that a mutation in Yersinia pestis, the source of the Black Death, caused the plague’s lethality, which wiped out about half of the European population during the Middle Ages. But paleopathologists working in conjunction with microbiologists and geneticists are discovering that the ancient pathogen is similar to the modern-day microbe. This raises the question of why the bacterium was so deadly in the past. The team has also discovered a mass grave, where they hope to recover DNA of Vibrio cholerae from the remains. This pathogen killed nearly 100,000 people in a worldwide pandemic in 2012. By understanding the evolution of this bacterium, scientists hope to discover the genetic changes that are associated with extreme virulence. The Italian project, like many other sites, involves remarkable support by the local inhabitants and human remains that are available for study. This contrasts with the situation in the United States. The Native American Graves Protection and Repatriation Act (NAGPRA) of 1990 requires that human remains affi liated with tribes must be returned to those tribes for reburial. It was the result of a compromise among organizations representing Native Americans, the scientifi c community, museums, and preservation interests. In many cases, NAGPRA has stimulated constructive interactions by all stakeholders. However, the Act hampers potential research and, although conceived with good intentions, is at times ambiguous. As a result of such legislation, the opportunities offered in Italy and other sites outside the United States have attracted many U.S. paleopathologists and bioarchaeologists. This is extremely unfortunate, as there is much to be learned from analysis of the ancient DNA of Native Americans. Understanding the origin and spread of smallpox, measles, typhoid, and other outbreaks in the New World will not only test long-held hypotheses about how disease devastated Native Americans, but should reveal the virulence of strains, how diseases spread, and how populations recovered. These are precisely the issues that researchers need answers to in considering future pandemics. To expand the sources of ancient remains in the United States, the scientifi c community must increase its engagement with the public, policy-makers, and tribal communities in ways that clearly explain how access to human remains, in an ethical and respectful manner, holds great potential for understanding the diseases that affect their own health. Different ecological settings that characterize archaeological sites offer opportunities to examine patterns of disease, as well as adaptive potentials and constraints. Ancient bones can help us deal with diseases in the future, and scientists should have an opportunity to study them.