Mary P. Ryan

Evolution of infectious Disease: A Biocultural Analysis of AIDS

The evolution of infectious disease can be understood from an ecological model that incorporates information from anthropology, epidemiology, and biomedicine. This model considers variables such as the pathogen, the host population, and the environment. In this model, the role that culture as well as other environmental variables plays in the transmission of infectious disease in human populations is considered. In addition, the sociocultural response and its impact on the disease process can be analyzed. The present AIDS epidemic is placed in an ecological and evolutionary context of the disease in hominid evolution. The interaction between Human Immunodeficiency Virus (HIV) and human populations is considered in this perspective. The ability of the virus to survive in semen and blood both increases as well as limits the possibility of transmission. Cultural practices that increase the transmission of blood and semen or increase sexual activity will obviously increase the potential risk of viral transmission. In societies that practice exchange of blood, blood transfusion, and where vaccinations with unclean needles exist or where there is intravenous (IV) drug use, the transmission of HIV by blood is enhanced. HIV which can cause a breakdown of the immunological system is paradoxically a very fragile pathogen. Replication occurs within T‐cells, an important part of the immunological system. Outside of the blood or semen the virus dies quickly. From the perspective of the pathogens adaptation, the virus has effectively solved the problem of survival. The fragile viruss long incubation period and its ability to survive in the presence of antibodies help to assure its transmission. HIVs ability to suppress the immunological system may assure its immediate survival, but this adaptation may cause the death of its host from other opportunistic pathogens that are usually not lethal.

Conference Panel: On Political Identity

In May, 1990, a conference was held at UCLA on the theme of “American Politics in Historical Perspective.” Panels were organized on political institutions and social history, on periodization, and on political identity. The panel presentations on political identity are printed below, along with some of the exchanges among the conference group. Slightly edited for clarity, they are offered to readers in the interest of conveying some of the intellectual ferment currently surrounding the focus on political identity and its use as an approach in historical study. The editors of Studies in American Political Development do not endorse any of the views or interpretations expressed.

Reproduction in American history.

The spectrum of experience subjected to historical analysis has enlarged dramatically over the last decade and taken scholars to the very border between biology and social organization-the study of human reproduction. Demographers led this investigation into the private domain, carefully examining variations in fertility and presenting their discoveries in mathematical models and tabulations. Now more traditional historians are advancing into this field of research. At work in the archives rather than at