Evolution Blogspot 39, Of What Value is the Study of Evolution?, Part II.

Practical applications of the Theory of Evolution, continued.

1. Medicine. Answers to questions about cancer, diabetes, and uncommon neurological disorders have become available from the information that has come out of genomic studies which, in turn, generated from evolutionary studies. Jonathan Eisen, Ph.D.–an evolutionary biologist and professor at U.C. Davis with appointments in the Departments of Medical Microbiology and Evolution and Ecolog–offers ten reasons for medical professionals to understand evolution:
   1. Antibiotic resistance. Understanding how antibiotic resistance originates and spreads is fundamentally a question of evolution. The more understanding medical professionals have about evolution, the less likely they will be to abuse antibiotics in human and animals.
   2. Origin and spread of virulence. Organisms can change their virulence properties on the short term owing to the processes of evolution. More importantly, behavior of medical personnel can both influence the spread of virulent strains and can unintentionally select for more virulent strains. Understanding evolution and the importance of hand washing are key.
   3. Vaccine use and development. Vaccines involve altering the evolutionary arms race between pathogens and hosts. It is not an intelligent design arms race. Vaccine work requires a committed understanding of that fact to produce safe, effective, and timely vaccines.
   4. Cancer origins. Cancer is, in essence, an analog of natural selection operating among cells within the body. The winners of this selection process are those that have uncontrolled growth. It is crucial to view cancer in its evolutionary context to be able to counter its origin, mutation, and spread.
   5. The human microbiome. Beneficial microbes are on and inside human bodies (as well as other animals). They are difficult to see, difficult to grow in lab cultures, and therefore difficult to study. The current methods of study are those developed by scientists studying evolution—indirect DNA based assays involving evolutionary and ecological analyses of the data. Understanding of these microbes is crucial for their survival and ours.
   6. Understanding the human genome. The human genome has almost completely been identified, and the genomes of multiple important other animals are known as well. The best way to learn about the genome sequence itself is through phylogenetic analyses comparing to other genomes. Medical, as well as evolutionary information, pertinent to the health and welfare of humans depends on the understanding of the important aspects of genetics and the genome.
   7. The relevance of animal and other models. Mouse, Drosophila, even yeast and E. coli have provided important insights into human embryology and pathology, genetic diseases, and how they can be altered. Models from these animals allow testing and manipulation that cannot be ethically done in humans and the information gleaned by years of evolutionary studies has proved to be invaluable for human well-being.
   8. Aging. Aging is a side effect of natural selection maximizing fitness by focusing on fitness and reproduction in the early years of life. Since there is little overall fitness cost to mutations that lead to deleterious effects in the aged, selection has generally overlooked that period of life. Any progress to be made in understanding or altering the adverse traits accompanying advanced age will come from a knowledge based on evolutionary studies of the efficiencies and inefficiencies of selection, and selecting genes and gene families susceptible to change and by a clear understanding of how to avoid costly errors for patients.
   9. The immune system. Over and above the issues of vaccines, the 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 such an integral part of medical practice that there are medical specialties that deal exclusively with issues of immunity. Understanding the immune system in the future will require evolutionary competence by the medical professional and will be an exercise in population genetics and natural selection, even more importantly that at present.

Mario R. Capecchi, PhD., Nobel Prize Laureate for his work in molecular biology (gene targeting), an evolutionary discipline, holds a professorship and endowed chair at the University of Utah in the Health Sciences Department as evidence of the value of his work to practical health issues. Capecchi’s long-time colleague, Raymond F. Gesteland, PhD, former University of Utah vice-president for research, said this of Capecchi’s work, “Mario’s science has evolved more and more in the direction of human disease. It’s a great example of basic research that ends up being of great value to society.” Capecchi himself said, “What makes us similar? That’s a powerful question. Similar genes work in pathways that are present in all organisms. We can look at the pathway of cancer, for instance, and learn about it in model organisms like the mouse. But the endpoint is the human being.”

Dr. Capecchi is involved in currently ongoing projects that include the creation of mouse models to study colon cancer, investigation of the role of fibroblast growth factors in limb development, and the role of Hox genes in embryonic development–specifically the development of limbs and motor nerves that enable the hind limbs to move. One of his students is studying the expression of the Hoxb8 grooming gene in the brains of mice during embryonic development with an eye towards its possible implications for human disease processes. In 2007, Capecchi wrote a paper entitled, A Conditional Mouse Model of Synovial Sarcoma: Insights into a Myogenic Origin, a study of a gene which–when activated–produced myoblasts which were 100% cancerous 100% of the time. The study has proved to be of major importance to the understanding of that devastating disease.