Paul W. Ewald
Encyclopedia
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 http://www.louisville.edu/a-s/biology/history.html.
Ewald asserts, along with a growing body of peer review
ed 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
. 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
. 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." One example of this is schizophrenia
; patients with the mental illness rarely reproduce. Ewald believes Schizophrenia may be caused by Borna
virus. 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.
His background in evolutionary biology helped form these theories. Another major influence was a fateful case of diarrhea in the late 1970s. 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.
magazine named Ewald as one of the "25 Visionaries Who Are Changing Your World" for his research on the link between infections and cancers.
Today, Jul/Aug 99, Examines the possible connection of microorganisms with psychological problems.
Infectious disease
Infectious diseases, also known as communicable diseases, contagious diseases or transmissible diseases comprise clinically evident illness resulting from the infection, presence and growth of pathogenic biological agents in an individual host organism...
. He received his B.Sc. in 1975 from the University of California, Irvine
University of California, Irvine
The University of California, Irvine , founded in 1965, is one of the ten campuses of the University of California, located in Irvine, California, USA...
, in Biological Sciences and his Ph.D. in 1980 from the University of Washington
University of Washington
University of Washington is a public research university, founded in 1861 in Seattle, Washington, United States. The UW is the largest university in the Northwest and the oldest public university on the West Coast. The university has three campuses, with its largest campus in the University...
, in Zoology
Zoology
Zoology |zoölogy]]), is the branch of biology that relates to the animal kingdom, including the structure, embryology, evolution, classification, habits, and distribution of all animals, both living and extinct...
, with specialization in Ecology
Ecology
Ecology is the scientific study of the relations that living organisms have with respect to each other and their natural environment. Variables of interest to ecologists include the composition, distribution, amount , number, and changing states of organisms within and among ecosystems...
and Evolution
Evolution
Evolution is any change across successive generations in the heritable characteristics of biological populations. Evolutionary processes give rise to diversity at every level of biological organisation, including species, individual organisms and molecules such as DNA and proteins.Life on Earth...
. He is currently director of the program in Evolutionary Medicine at the Biology Department of the University of Louisville http://www.louisville.edu/a-s/biology/history.html.
Ewald asserts, along with a growing body of peer review
Peer review
Peer review is a process of self-regulation by a profession or a process of evaluation involving qualified individuals within the relevant field. Peer review methods are employed to maintain standards, improve performance and provide credibility...
ed 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
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
or protozoa
Protozoa
Protozoa are a diverse group of single-cells eukaryotic organisms, many of which are motile. Throughout history, protozoa have been defined as single-cell protists with animal-like behavior, e.g., movement...
. For example, cervical cancer
Cervical cancer
Cervical cancer is malignant neoplasm of the cervix uteri or cervical area. One of the most common symptoms is abnormal vaginal bleeding, but in some cases there may be no obvious symptoms until the cancer is in its advanced stages...
can be caused by the human papilloma virus; some cases of liver cancer are caused by hepatitis
Hepatitis
Hepatitis is a medical condition defined by the inflammation of the liver and characterized by the presence of inflammatory cells in the tissue of the organ. The name is from the Greek hepar , the root being hepat- , meaning liver, and suffix -itis, meaning "inflammation"...
C or B; the bacteria Helicobacter pylori
Helicobacter pylori
Helicobacter pylori , previously named Campylobacter pyloridis, is a Gram-negative, microaerophilic bacterium found in the stomach. It was identified in 1982 by Barry Marshall and Robin Warren, who found that it was present in patients with chronic gastritis and gastric ulcers, conditions that were...
has been proven to cause stomach ulcers
Peptic ulcer
A peptic ulcer, also known as PUD or peptic ulcer disease, is the most common ulcer of an area of the gastrointestinal tract that is usually acidic and thus extremely painful. It is defined as mucosal erosions equal to or greater than 0.5 cm...
. His research extends these findings to a wide variety of other ailments.
Ewald disagrees with the popular theory that genes
Gênes
Gênes is the name of a département of the First French Empire in present Italy, named after the city of Genoa. It was formed in 1805, when Napoleon Bonaparte occupied the Republic of Genoa. Its capital was Genoa, and it was divided in the arrondissements of Genoa, Bobbio, Novi Ligure, Tortona and...
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." One example of this is schizophrenia
Schizophrenia
Schizophrenia is a mental disorder characterized by a disintegration of thought processes and of emotional responsiveness. It most commonly manifests itself as auditory hallucinations, paranoid or bizarre delusions, or disorganized speech and thinking, and it is accompanied by significant social...
; patients with the mental illness rarely reproduce. Ewald believes Schizophrenia may be caused by Borna
Borna
Borna is a town in the Free State of Saxony, Germany, capital of the Leipzig district. It is situated approx. 30 km southeast of Leipzig. It has approx. 21,000 inhabitants.-History:Borna as a town is more than 750 years old....
virus. 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
Breast cancer
Breast cancer is cancer originating from breast tissue, most commonly from the inner lining of milk ducts or the lobules that supply the ducts with milk. Cancers originating from ducts are known as ductal carcinomas; those originating from lobules are known as lobular carcinomas...
, the other twin has only a 20% chance of developing the disease.
His background in evolutionary biology helped form these theories. Another major influence was a fateful case of diarrhea in the late 1970s. His first thought during this bout was that his body was using diarrhea to expel the pathogen
Pathogen
A pathogen gignomai "I give birth to") or infectious agent — colloquially, a germ — is a microbe or microorganism such as a virus, bacterium, prion, or fungus that causes disease in its animal or plant host...
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
AIDS
Acquired immune deficiency syndrome or acquired immunodeficiency syndrome is a disease of the human immune system caused by the human immunodeficiency virus...
virus which is inactive for years (allowing it to spread) before terminal
Terminal illness
Terminal illness is a medical term popularized in the 20th century to describe a disease that cannot be cured or adequately treated and that is reasonably expected to result in the death of the patient within a short period of time. This term is more commonly used for progressive diseases such as...
, chronic
Chronic (medicine)
A chronic disease is a disease or other human health condition that is persistent or long-lasting in nature. The term chronic is usually applied when the course of the disease lasts for more than three months. Common chronic diseases include asthma, cancer, diabetes and HIV/AIDS.In medicine, the...
and deteriorative ailments incapacitate and finally kill the victim.
Awards
In 2010, Utne ReaderUtne Reader
Utne Reader is an American bimonthly magazine. The magazine collects and reprints articles on politics, culture, and the environment from generally alternative media sources, including journals, newsletters, weeklies, zines, music and DVDs...
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." - William D. Hamilton
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 DiseaseEvolution of Infectious DiseaseEvolution of Infectious Disease is a 1993 book by the evolutionary biologist Paul Ewald. In this book Ewald contends the traditional view that parasites should evolve toward benign coexistence with their hosts. He draws on various studies which contradict this dogma and asserts his own theory...
, 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 AmericanScientific AmericanScientific American is a popular science magazine. It is notable for its long history of presenting science monthly to an educated but not necessarily scientific public, through its careful attention to the clarity of its text as well as the quality of its specially commissioned color graphics...
.
See also
- Human Microbiome ProjectHuman microbiome projectThe Human Microbiome Project is a United States National Institutes of Health initiative with the goal of identifying and characterizing the microorganisms which are found in association with both healthy and diseased humans . Launched in 2008, it is a five-year project, best characterized as a...
- Koch's postulatesKoch's postulatesKoch's postulates are four criteria designed to establish a causal relationship between a causative microbe and a disease. The postulates were formulated by Robert Koch and Friedrich Loeffler in 1884 and refined and published by Koch in 1890...
- List of human diseases associated with infectious pathogens
- Medical microbiologyMedical microbiologyMedical microbiology is both a branch of medicine and microbiology which deals with the study of microorganisms including bacteria, viruses, fungi and parasites which are of medical importance and are capable of causing infectious diseases in human beings...
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 TEDTED (conference)TED is a global set of conferences owned by the private non-profit Sapling Foundation, formed to disseminate "ideas worth spreading"....
in 2007
Today, Jul/Aug 99, Examines the possible connection of microorganisms with psychological problems.