Tag: Misc.

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.

Well, in my last post I asked if people were committed to “Evolution” and I confess I got a bit worried that this might be misinterpreted by some as “We believe in evolution regardless of the facts.” And in fact there was one flame-like comment posting that I deleted from the comments.

But now apparently the Pope has read my blog (or maybe someone told him about it) and he has come out in full support of evolution as a science and the facts of evolution as we evolutionary biologists know then (i.e., natural selection, macro and microevolution, etc).

As reported on MSNBC the Pope said

the debate raging in some countries —particularly the United States and his native Germany — between creationism and evolution was an “absurdity,” saying that evolution can coexist with faith.

In addition, he said

They are presented as alternatives that exclude each other,” the pope said. “This clash is an absurdity because on one hand there is much scientific proof in favor of evolution, which appears as a reality that we must see and which enriches our understanding of life and being as such.

Furthermore, and more importantly, the Pope has re-stated his belief that everyone must do something about global change and environmental destruction:

“We cannot simply do what we want with this Earth of ours, with what has been entrusted to us,” said the pope, who has been spending his time reading and walking in the scenic landscape bordering Austria.

I know I said recently that biology had a good day in the Bush administration. Unfortunately, that was mostly genetics and biochemistry. Evolution and environmental stewardship never seem to have good days there. Maybe just maybe, the Pope will have some impact around the world on both issues even as the U.S. sticks its head in the sand. NOTE – SEE COMMENTS – THE POPE IS PRETTY CLEARLY NOT DOING EVERYTHING HE COULD TO PROTECT THE ENVIRONMENT.

Peggy Farnham at the U. C. Davis Genome Center sent me this picture. apparently of a real tattoo. After a google search I found at least an early source for it here.

This inspires me to ask everyone out there – are you committed to Evolution? What have you done to show your commitment?

What have I done? I think the biggest example of my commitment, though boring, is that I worked six years on a new evolution textbook which was just published a few weeks ago (which you can find out about here or order from Amazon here).

Less boring – I once stood on a street corner in New Orleans with Owen White and handed out altered forms of a pamphlet someone else was handing out in which we added some information about evolution.

So – rather that spout off about what I have done .. what has anyone else done? Are you committed?