It has been shown that human evolution, in the form of natural selection for particular traits, can occur over the short term-just a few generations, “the blink of an eye to evolutionary biologists,” according to Yale University evolutionary biologist Stephen Stearns, one of the NESCent meeting organizers. So what does understanding our evolutionary history add to our ability to improve human health? All in all, medicine seems to be making great progress in preventing, treating, and curing disease without including evolutionary information. More recently, genomic studies have opened the door to studying genetic differences between populations, bringing us the possibility of more effective individualized medicine. Over time, doctors have learned more about the relationship between environment and disease, including factors such as hygiene and lifestyle. The field of medicine has developed to address the wide array of environmental and lifestyle-induced diseases. In fact, a recent study presents evidence that evolution may have been occurring even faster in human populations than expected over the past 10,000 years (Hawks et al. As the title of the meeting- Evolution in Contemporary Human Populations: Medical, Genetic and Behavioral Implications (Govindaraju 2007)-suggests, this group of scientists clearly share the belief that evolution is going on in contemporary human populations. Although the participants work on different aspects of human health, they all realize the value of evolution in their work.
In May 2007, evolutionary and medical researchers, doctors, ethicists, and anthropologists met at the National Evolutionary Synthesis Center to catalyze the emerging scientific discipline known as evolutionary medicine.
Genes are important, environment is important, the interaction between the two is important-but so is human evolution, as it exerts an ongoing influence on characteristics of the human population. Initiatives such as the Human Genome Project and the Haplotype Map have provided new tools for studying evolution and human health. Evolution is providing clues about puzzling medical results, and studies of human health are giving us new information about the rate and driving forces of evolution. Recently, however, these traditions have been giving way to a new approach, as researchers and medical practitioners discover connections based on evolutionary biology that are leading them to new conclusions about their respective fields. Other evolutionary studies have seemed far removed from contemporary human health issues. Conversely, evolutionary biologists have not traditionally paid much attention to the medical implications or applications of their findings, with a few exceptions such as the study of emerging infectious diseases.
An evolutionary viewpoint pushes the focus out farther to look at long-term ecological relationships, including symbiotic bacteria, parasites and pathogens, historical lifestyles, and the genetics of populations. Medical practice tends to focus on the immediate, or proximate, causes of disease, including genetics and lifestyle, to identify a potential treatment. Evolution has not traditionally been considered to be an important aspect of medicine, and medical practitioners and researchers have not traditionally approached their work from the perspective offered by evolutionary biology.