A new paper in Science represents one of the best recent accounts of why thinking about evolutionary biology is a lot more than an academic enterprise, but actually matters for understanding – and solving – problems that confront us on a global scale.
For those of us working in evolutionary biology, the piece is not surprising, but it is refreshing. I have found that as I have given talks on research in evolutionary psychology, a frequent response that I receive is that I didn’t “need” to know anything about evolution in order to do the sort of research that I do. There is a sense that is correct: one could, in principle, arrive at a hypothesis through intuition, blind empiricism, or any number of any pathways. Evolutionary ideas provide, to my mind, a useful hypothesis-generation engine, and the success of the field seems to vindicate this point of view.
Scott Carroll and colleagues provide additional reasons for the importance of understanding evolutionary biology, and show that these ideas have applications ranging from areas of healthcare to fighting the spread of harmful pathogens to agricultural policy.
Carroll et al., for instance, take up a point made by researchers in evolutionary psychology. Back in 2001, for instance, Terry Burnham and Jay Phelan in their book Mean Genes, discussed the implications of the fact that there is a “mismatch” between the environments that selected for the human genome and the environment that humans currently inhabit. Carroll et al. point out that this mismatch has tremendous costs both in lives and the loss of economic activity:
Some of the most serious non-communicable diseases in humans may be prevented by better aligning current environments with those in which our hunter-gatherer ancestors evolved. Sedentary modern lifestyles and diets with high glycemic processed foods are increasingly implicated in the rapidly rising rates of obesity, diabetes and cardiovascular disorders. These mismatch disorders are estimated to contribute to about two-thirds of all deaths in Western societies and to a growing proportion of deaths in developing countries.
Carroll et al. point out that thinking about human ancestral environments, and the diets our bodies evolved to consume, might go some way to understanding how to combat this global health challenge.
Another global health challenge relates to the evolution of parasites. Many people know, for instance, that the use of antibiotics has led to selection for antibiotic-resistant pathogens: pathogens in patients that are susceptible to any given antibiotic are killed, failing to reproduce, leaving their resistant cousins free reign. Somewhat less well known is a similar problem in agriculture. Carroll et al. point out that the pervasive use of herbicide has selected for resistant species, representing a profound danger to important food crops. Armed with knowledge of evolutionary biology, however, scientists have developed a technique to slow this process. Farmers grow “refuges” in which a pesticide is not present, allowing the pest in question to reproduce. This gives rise to a large number of pathogens that have not been selected to be resistant. As they mate with other members of their species, they produce offspring who similarly lack resistance, making them susceptible to herbicides.
Carroll et al. close with an argument that implies that meeting global challenges relies on understanding not only evolutionary biology, but also psychology and economics. Consider these “refuges.” From the standpoint of the entire agricultural community, such refuges represent a benefit: the presence of refuges leads to more herbicide-sensitive pathogens over time. However, from the standpoint of each farmer, a refuge is a cost, since refuges contain crops that are damaged by pathogens, unprotected as they are by the pesticide in question. This gives each farmer the incentive to abolish her refuge, to maximize profits, leading to a well-studied commons dilemma. Solving this problem is, at its heart, a task for economists, political scientists, and policy makers.
As TVOL retools itself for the future, this piece constitutes excellent reading for anyone interested in the vast reach of evolutionary biology into human affairs.