The good news: improved health care is reducing occurrences of intestinal parasites worldwide. The bad news: at the same time, rates of asthma are increasing worldwide. The link between these trends? Evolution – human evolution. The human immune system has evolved in the constant presence of intestinal parasites. The immune system is designed to react to these parasites – in their absence, the immune system overreacts to simple allergens, resulting in asthma. Its evolved state is mismatched to modernity. Similar mismatches produce increased risk of diabetes, obesity, and cardiovascular disease in modern adult populations. Globalization is making understanding these types of complex evolutionary relationships more relevant in medicine as human environments change. As globalization improves standards of living, it also elicits medical surprises and disease burdens that can be illuminated by evolutionary insights.
In his book Evolution in Health and Disease (Oxford University Press, 1998), meeting co-organizer Dr. Stephen Stearns examines the relationship between human biology, lifestyle and health. He describes how human biology is the result both of macroevolution – changes occurring over a long period of time, and microevolution – changes occurring right now. The recent history of humans includes major changes in lifestyle in industrialized and developing countries that have altered the selective pressures on humans. The ensuing microevolutionary consequences present novel medical problems and offer new possibilities for clinical interventions.
"These ideas are novel, exciting, and much in need of further investigation and testing," says Stearns. "Evolutionary thinking definitely sheds useful light on medical research and practice. It complements other approaches. It does not replace them."
Evolution has not traditionally been considered an important aspect of medicine, but recently researchers from various fields are finding connections based on evolutionary biology that are leading them to new conclusions about their research and results. Combined with the vast quantities of data available due to the genomics revolution and various long-term health surveys such as the decades-long Framingham Heart Study, this "big picture" synthetic view is leading to a new approach called evolutionary medicine.
Dr. Stearns and two other leaders in this emerging field, Dr. Peter Byers of the University of Washington and Dr. Diddahally Govindaraju of the Boston University School of Medicine, have organized this meeting to bring together leading researchers from evolutionary biology, medicine, human biology and genetics, and public health. Their objective will be to synthesize and stimulate ongoing research on evolution in contemporary human populations, in order to foster beneficial interactions between medical science and evolutionary biology.
Meeting participants will survey the available evidence in long-term health studies and examine the range of evolutionary ideas that could be applied to and tested with that body of evidence. The group will work on developing a set of specific recommendations on how to design long-term studies in the future so as to reflect and to test evolutionary thought.
Initial work will use data from NIH clinical trials, including the renowned Framingham Heart Study. "Multigenerational and longitudinal clinical cohorts such as the Framingham Heart Study population provide unique opportunities to study ongoing evolutionary processes," says Govindaraju. "In some of these populations, risk factors that lead to overt manifestation of diseases…have been accurately measured [in] thousands of individuals. Thanks to this wealth of data, he adds, "these epidemiological studies provide a perfect scenario to study evolutionary changes that are taking place at the genomic, physiological and morphological levels among individuals, families and populations, and to extend these results to prescribe medications based on natural relationships of individuals based on evolutionary principles."
By catalyzing a synthesis between medicine and evolutionary biology, the meeting will help document ongoing evolutionary processes in modern human populations and the influence of evolutionary principles on human health and disease processes. Ultimately, the conference will help to advance a new scientific discipline rich with the potential to increase understanding of human health and disease, and improve human health and longevity.
Written from a news release by National Evolutionary Synthesis Center (NESCent).