Paul W. Ewald

Paul W. Ewald is an evolutionary biologist, specializing in the evolution of infectious disease. He received his B.Sc. in 1975 from the University of California, Irvine, in Biological Sciences and his Ph.D. in 1980 from the University of Washington, in Zoology, with specialization in Ecology and Evolution. He is currently director of the program in Evolutionary Medicine at the Biology Department of the University of Louisville [1].

Ewald asserts, along with a growing body of peer reviewed studies published in mainstream scientific journals, that many common diseases of unknown origin are in fact the result of the presence of slowly acting infections caused by viruses, bacteria or protozoa.^{[citation needed]} For example, cervical cancer can be caused by the human papilloma virus; some cases of liver cancer are caused by hepatitis C or B; the bacteria Helicobacter pylori has been proven to cause stomach ulcers.^{[citation needed]} His research extends these findings to a wide variety of other ailments.

Ewald disagrees with the popular theory that genes alone dictate certain disease susceptibility. He says "A disease-causing gene that reduces survival and reproduction would normally eliminate itself over a number of generations."^{[citation needed]} One example of this is schizophrenia; patients with the mental illness rarely reproduce. Ewald believes Schizophrenia may be caused by Borna virus.^{[citation needed]} He argues that this disease would have already been eliminated if it were from a strictly genetic cause. He also points out that in the case of gene sharing identical twins where one develops breast cancer, the other twin has only a 20% chance of developing the disease.^{[citation needed]}

His background in evolutionary biology helped form these theories. Another major influence was a fateful case of diarrhea in the late 1970s.^{[citation needed]} His first thought during this bout was that his body was using diarrhea to expel the pathogen and he should avoid anti-diarrheal medication. Looking at the problem from the standpoint of the organism, expulsion was not an evolutionary benefit. The only benefit to the pathogen causing the sickness would be the potential transmission to other hosts; much like the particulate expelled during coughing, diarrhea can be a means of distribution. This thinking sparked his curiosity of the evolutionary process of infections.

Another major influence on Ewald's thinking has been the AIDS virus which is inactive for years (allowing it to spread) before terminal, chronic and deteriorative ailments incapacitate and finally kill the victim.^{[citation needed]}

Awards

In 2010, Utne Reader magazine named Ewald as one of the "25 Visionaries Who Are Changing Your World" for his research on the link between infections and cancers.

Quotes

• "[Ewald's theory] opens our eyes to many quite weird possibilities about disease that most medical scientists, tending to be unaware of current evolutionary thought, don't think of.^{[citation needed]}" - William D. Hamilton

Books & articles by Paul W. Ewald

Popular books by Paul W. Ewald

• Plague Time: The New Germ Theory of Disease, Anchor, 2002, ISBN 0-385-72184-6

Academic books and articles by Paul W. Ewald

• "Transmission Modes and the Evolution of Virulence, with special reference to Cholera, Influenza, and AIDS," Human Nature, Vol. 2, No. 1, 1991, pp. 1–30.

• Evolution of Infectious Disease, Oxford University Press, 1993, ISBN 0-19-506058-X.

• "Emerging pathogens: Insights from evolutionary biology," Emerging Infectious Diseases, Vol. 2, 1995, pp. 245–257.

• "The evolution of virulence: a unifying link between ecology and parasitology," Journal of Parasitology, Vol. 81, pp. 659–669.

• "Vaccines as evolutionary tools: The virulence-antigen strategy," in Concepts in Vaccine Development (S. H. E. Kaufmann, ed.), Walter de Gruyter & Co:Berlin, 1996, pp. 1–25.

• "Alternative transmission modes and the evolution of virulence," (with Giulio De Leo), in Adaptive Dynamics of Infectious Diseases: In Pursuit of Virulence Management Series: Cambridge Studies in Adaptive Dynamics (No. 2), (Ulf Dieckmann ed.), 2002, ISBN 0521781655.

• "Virulence Management in Humans," in Adaptive Dynamics of Infectious Diseases: In Pursuit of Virulence Management Series: Cambridge Studies in Adaptive Dynamics (No. 2) (Ulf Dieckmann ed.), 2002, ISBN 0521781655.

Popular articles about Paul W. Ewald

• Steve Mirsky, Profile: Paul W. Ewald, A Host with Infectious Ideas, May 2001, Scientific American.

See also

• Human Microbiome Project
• Koch's postulates
• List of human diseases associated with infectious pathogens
• Medical microbiology

External links

• A New Germ Theory. Originally published in The Atlantic Monthly magazine, February 1999
• Guarding Against the Most Dangerous Emerging Pathogens: Insights from Evolutionary Biology, by Paul W. Ewald, CDC website
• PANDAS (Paediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococci) and PITAND (Paediatric Infection-triggered Autoimmune Neuropsychiatric Disorders)
• Closer to Truth: PBS TV show, with Paul Ewald and others.
• Biologist Paul Ewald Says Germs, Not Genes, Cause Most Killer Diseases
• The Infection Connection by Harriet Washington, Psychology
• TED Talks: Paul Ewald asks, Can we domesticate germs? at TED in 2007

Today, Jul/Aug 99, Examines the possible connection of microorganisms with psychological problems.