Why all medical professionals need to study evolution

As an evolutionary biologist with a 50% appointment in a medical school (in the Med. Micro. and Immunology department at U. C. Davis - my other 50% is in the Section of Evolution and Ecology on the main campus) I am somewhat dismayed by the lack of attention evolution receives in Medical Schools.

So I am starting a new thread here on my blog about why medical professionals need to understand evolutionary biology. First, there is a great site out there for people who want to learn more called the "Evolution and Medicine Network" which has links to courses, articles, books, etc.

Here are my top 10 picks for reasons medical professional need to understand evolution

1. Antibiotic resistance. The emergence and spread of antibiotic resistance is one of the most vexing issues in medicine right now as well as one of the best studied topics in the evolution of microorganisms. Understanding how antibiotic resistance originates and spreads is fundamentally a question of evolution. The more medical professionals understand this issue the better they will be at preventing spread in hospitals and in convincing patients and the community to stop abusing antibiotics in human and animal care.
   
2. Origin and spread of virulence. Not all pathogens are equal. Some are minor annoyances. Others produce really nasty outcomes. And importantly, organisms can change these virulence properties on the short term. Even more importantly, behavior of medical personnel can both influence the spread of virulent strains (can anyone say - wash your *$&% hands) and can unintentionally select for more virulent strains. Understanding the evolution of virulence is critical for making sure health care does not make things worse (see papers by Ewald for example).
   
3. Vaccine use and development. Vaccines involve altering the evolutionary arms race between pathogens and hosts. It is not an intelligent design arms race. If you do not get the difference, stay out of vaccine work.
   
4. Cancer origins. Cancer is in essence a analog of natural selection operating among cells within the body. Unfortunately for us, the "winners" of this selection process are those that have uncontrolled growth. Thinking of cancer in this way can help understand how to both prevent and treat it.
   
5. The human microbiome. Beneficial microbes are all over us and play fundamental roles in human health. Unfortunately they are very hard to study because, well, they are small, and many cannot be grown in culture in the lab. The current ways to study them primarily involve indirect DNA based assays involving evolutionary and ecological analyses of the data.
   
6. Understanding the human genome. The human genome is done (well, almost, but close enough for most uses). Now what? Well, the best way to learn about the genome sequence itself is through "phylogenomic" analyses comparing to other genomes.
   
7. The relevance of animal and other models. Mouse is a useful model for some aspects of human biology but not all. Drosophila too. And even yeast and E. coli? Which aspects of human biology can be modelled by each model organism? Understanding their evolutionary history and evolutionary processes helps figure this out.
   
8. Aging. Aging is in essence an unfortunate side effect of natural selection maximizing fitness by futzing with health and reproduction in the early years. Since there is little fitness cost to mutations that lead to deleterious effects when we are old, well, we are kind of screwed. But understanding the ailments associated with aging is best done with this knowledge of the efficiencies and inefficiencies of selection.
   
9. The immune system. See #3 above. But this is bigger than that. The whole process of how the immune system (both the innate and the adaptive components) works both at the level of an individual and at the level of a population is an exercise in population genetics and natural selection.
   
10. Pluses and minuses of high mutation and recombination rates. Many medical professionals know HIV has a high mutation rate. And some might know that recombination rates are high in some pathogens. What are the consequences of this on the pathogen biology? Read Evolution 101, or my new textbook.
    
11. A bonus one. Epidemiology of infectious diseases. One of the best tools in studying the spread of infectious diseases is phylogenetic analysis - which can show how different strains are related to each other.
    

Just a brief tour of some of the areas that evolutionary biology informs medicine. More on this later.