Dr. Cockburn is well trained and has had impressive experience with infectious diseases around the world. He describes his book as "a bird's-eye view of the relationships between host, parasite, and environment" and states that a specialist "is likely to find errors and omissions within his special knowledge."
The first chapter, "The Role of Speculation in Research," notes common distrust of "speculation," as, for example, the prejudice (based partly on negative experiments) of malariologists against considering simian malaria important in human disease until the recent demonstration of mosquito transmissibility to humans of Plasmodium vivax-like simian parasites.
In chapters on "Evolutionary Background," "Paleoepidemiology," "The Evolution of Infectious Diseases," and "The Species Concept in Microbiology," the author applies principles of evolution and genetics in speculating on the development of pathogenic organisms from originally "free living forms." He cites the recent discovery of Treponema zuelzerae (which contains "Reiter antigen") as an example