Christopher Wills is a professor of Biology at the University of California, San Diego, who has written several general-audience books about biology topics, including genetics and the brain. In Yellow Fever, Black Goddess (published simply as Plagues in Britain), he offers an intelligent and sophisticated discussion of the development of diseases, concentrating on the implications of those developments for the diseases themselves as well as for the people they afflict. In the course of describing evolutionary pressures on disease organisms, Wills describes the social conditions that provide diseases with opportunities to spread and closes with a discussion of recent research, including his own, that sheds some light on the coevolution of living things and their diseases.

Wills uses plague, cholera, typhoid, typhus, malaria, syphilis, and AIDS in examples that show a progression of evolutionary strategies used by disease. As social conditions change to make humans more and less vulnerable in various ways -- from proximity to nutrition to hygiene -- different diseases have arisen to take advantage of opportunities or have receded in the face of opportunities lost. This is extremely interesting stuff, simultaneously showing the vulnerability of diseases, so easily thwarted by the skin or the stomach acids, and their adaptability, as when they tuck themselves into recesses of the body out of easy reach of the immune system (typhoid in the gall bladder), or when they evolve to trick or blind the immune system more directly (HIV).

Wills is at his best when he is closest to biology. He has traveled widely, and that experience could form the basis for some very interesting discussions alongside the main topic of the book. But the descriptions of political conditions can be disconcerting or misleading -- like casually describing his "religious" use of an anti-malarial drug when visiting a country whose inhabitants could never afford it themselves or describing the Rwandan Hutus as a "rebel force". Wills acknowledges that he is a "privileged member of the First World", but what was probably intended as a regretful remark about the vast disparity between the rich and poor sounded rather more smug. And the Hutus were often victimized by the Tutsis over the course the past centuries, but his description neatly glosses over 30 years of Hutu rule -- punctuated regularly by massacres of Tutsis -- that makes his description of the Hutus in 1994 as terrified refugees and downtrodden rebels bizarre to say the least. (Also reviewed in The Net Net: Season of Blood: A Rwandan Journey, by Fergal Keane, treats the Hutu-Tutsi conflict and describes events leading up to the 1994 massacres.)

Happily, the subject at hand is front and center in Yellow Fever, Black Goddess: The Coevolution of People and Plagues. Wills makes the obligatory observations about antibiotic resistance, of course, and he goes further by describing just what kinds of developments these organisms are making to resist our medications (as well as how creative research is becoming in seeking new ways not just to kill bugs but to break disease cycles). Wills offers very interesting discussions of fighting disease, both artificially and with an evolving immune system, and his discussions of herd immunity -- both post-immunization and genetic -- help to explain the value of "genetic diversity" in a particularly lucid way.

Read Yellow Fever, Black Goddess for the science. The treatments of the more traditional stories of the history of epidemiology are appealing and interesting as well, but Wills's strength is clearly in his strong and engaging description of science, its discoveries and its methods. Moreover, by describing humans' changes to their environments as evolutionary pressures for diseases (a particularly useful context for discussing antibiotic resistance), Wills is able to paint a larger, more complete picture -- a picture of a system in which deliberate changes are met with adaptations from organisms that seem to want to live as much as humans want to be rid of them.