Some articles have the word “classic” written all over them, even on their first day of publication. Such an article appeared in the September 11 2014 issue of ScienceXpress, an electronic publication that features selected articles of the premier journal Science before they appear in print. Authored by a team of ten scientists headed by Scott P. Carroll, founding director of the Institute for Contemporary Evolution, it was titled “Applying Evolutionary Biology to Address Global Challenges.”
The words “evolutionary biology” and “global challenges” are seldom mentioned in the same breath. For most people, evolution is a slow process that might account for the way species are but cannot address the rapid changes taking place all around us, such as human-induced environmental and climate change. The key insight of the article is that evolution takes place on ecological time scales. Moreover, even when genetic evolution can’t keep pace with environmental change, a sophisticated knowledge of evolution is required to understand and manage the mismatch between organisms adapted to past environments and their current environments.
These insights are not brand new within the field of evolutionary biology. They date back to classic studies in the 1970’s by scientists such as John Endler working on guppies and Peter and Rosemary Grant working on Darwin’s Finches, showing that genetic change can take place even in a single generation and that organisms are consequently adapted to their environments at a much finer spatial and temporal scale than previously imagined. For the most part, however, awareness among evolutionary biologists does not extend to the general public or the many communities of scientists and policy experts attempting to address global challenges of all sorts.
Something else is common knowledge among evolutionary biologists but little known by others—the very idea that a single theoretical framework can address all topics concerning the living world. The generality of evolutionary theory is what made it seem so momentous in Darwin’s day (read the final paragraph of the Origin of Species). By the 1970’s the geneticist Theodosius Dobzhansky could utter his famous proclamation “Nothing in biology makes sense except in the light of evolution.” Nearly half a century later, the only thing wrong with this statement is that it has become trite with overuse. But step outside evolutionary biology and you enter a world that utterly lacks a unifying theoretical framework. In my book Evolution for Everyone I write that the Ivory Tower would be more aptly named the Ivory Archipelago—many islands of thought with little communication among islands. The world of public policy is even worse, with a separate community for each policy issue. When Carroll et al. move effortlessly from cancer to crop breeding, from obesity to preserving endangered species, they are doing what comes naturally to an evolutionary biologist but it provides a new model for the wider community attempting to address global challenges. In short, “Applying Evolutionary Biology to Address Global Challenges” deserves to become a classic. The more widely it is read, the more effectively we will surmount our challenges.
Yet, for all its admirable qualities, the Carroll et al. article reports only half a synthesis. For a glimpse of the other half, consider an article titled “Evolving the Future: Toward a Science of Intentional Change”, published in the journal Behavioral and Brain Sciences at about the same time as the Carroll et al. article. I am the lead author and my co-authors, Steven C. Hayes, Anthony Biglan, and Dennis Embry, are leaders in the applied behavioral sciences. The goal of our article is much the same as the Carroll et al. article: to sketch a unified science of intentional change that is centered on evolutionary theory. But whereas their article deals with topics such as cancer, antibiotic resistance, and gene therapy, our article deals with topics such as psychotherapy, early childhood education, urban revitalization, and economics. The lack of overlap between the topics covered by the two articles reflects a fundamental shortcoming in contemporary evolutionary theory that our article attempts to address—its confinement to genetic evolution.
Darwin knew nothing about genes. For him, the three ingredients of natural selection were variation, selection, and heredity, defined as a resemblance between parents and offspring. Yet, when the rediscovery of Mendel’s work in the early 20th century led to the sciences of genetics and population genetics, the study of evolution became almost entirely gene-centric. Say the word “evolution”, and evolutionary biologists and the lay public alike hear the word “genes”. A prime example is provided by the Carroll et al. article, which defines evolution as “the change in genetic makeup of a population” as if no other mechanism of inheritance exists.
This position is indefensible in my opinion. In fact, I will hazard a prediction that when pressed on the issue (as I am doing in this article), all ten authors of the Carroll et al. article will back away from their definition. Of course evolution requires heritable variation, not genetic heritable variation per se, and all of the major consequences of evolution follow from any mechanism of inheritance (although there can also be important differences). An uncontestable example is evolutionary algorithms implemented on computers. The fact that all ten authors reflexively defined evolution in terms of genetic evolution, despite being so synthetic in other respects, demonstrates just how gene-centric the field of evolutionary biology has become.
A single book—Evolution in Four Dimensions by Eva Jablonka and Marion J. Lamb—does a masterful job of expanding evolutionary theory beyond genetic evolution. After a concise but authoritative history of evolutionary thought that explains why it became so gene-centric, Jablonka and Lamb describe three additional mechanisms of inheritance and their interactions: epigenetics (the inheritance of patterns of gene expression), forms of social learning found in many species, and forms of symbolic thought that are distinctively human. Like the Carroll et al., article, Evolution in Four Dimensions deserves to become a classic and the publication of a second edition in 2013 following its original publication in 2006 is a good sign. I assign it as a first text in most of my classes and nearly all of my students are amazed. Biology majors never imagined on the basis of their previous education that there is more to evolution than genetic evolution. Non-biology majors never imagined that their topic areas such as cultural anthropology, social psychology, economics, political science, sociology, history, and the humanities can be approached using the same theoretical framework that has proven itself in the biological sciences—not because everything is a matter of genes, but because of additional inheritance systems. The very word “biology” loses its meaning. Epigenetic inheritance mechanisms are just as “biological” as genetic inheritance mechanisms, but are the mechanisms of social learning and symbolic thought any less “biological”?
The synthesis required for evolutionary science (a better word choice than biology) to address global challenges won’t be complete until all mechanisms of inheritance are included. What stands in the way of a full synthesis? One thing that doesn’t stand in the way is the quality of scientific research on non-genetic inheritance mechanisms. Human-related research from an evolutionary perspective is commonly branded as inferior in quality, a sorry collection of just-so stories compared to the more rigorous study of genetic evolution. The peer-review process says otherwise. To pick Behavioral and Brain Sciences as an example, its impact factor is ranked first among 49 behavioral science journals and third among 244 neuroscience journals. Target articles are subjected to a grueling review process and further scrutiny by approximately two dozen commentators. Our target article reports dozens of randomized control trials, the gold standard of assessment for intentional change practices, and the commentaries are largely supportive, while recognizing that much new ground remains to be broken. Going beyond our own article, I conducted a survey of all target articles published in BBS during the period 2001-2004. Approximately a third of them were from an evolutionary perspective. Far from occupying the fringes of the scientific literature, the study of human psychological and cultural change from an evolutionary perspective is at the cutting edge.
If the quality of science doesn’t stand in the way of a completed synthesis, what does? It’s easy to understand the reluctance of scientists and scholars from the human-related disciplines, especially given the legacy of Social Darwinism and efforts to define these disciplines in ways that cannot be “reduced” to “biology”. But why should evolutionary biologists be reluctant? Why aren’t they eager to expand the domain of their subject beyond genetic evolution? I don’t fully understand why evolutionary biologists are reluctant, but I can report that many of them are, at such a visceral level that there is no logical explanation. They just don’t want to go there.
An example unfolded at about the same time that the Carroll et al. article and our own BBS article were published. I was in Norway on Evolution Institute business. The EI formulates public policy from an evolutionary perspective. One of our projects examines the concept of quality of life, including Norway as a case study of cultural evolution at the national scale leading to a high quality of life. The Norway Project (as we call it) has been an amazing experience and the open-minded interest of Norwegian scientists, scholars, politicians, trade unions, policy experts, and the general public has been gratifying. To date, the most negative reaction has been from an evolutionary biologist named Glenn-Peter Saetre, who is a professor at the University of Oslo’s highly regarded Center for Ecological and Evolutionary Synthesis (CEES). In a newspaper article and public event where we shared the stage, Prof. Saetre was resolute that evolution should be defined in terms of genetic evolution and warned of the dangers of “biologizing” the human sciences.
Before continuing, I want to stress that I admire Prof. Saetre as an evolutionary biologist and CEES as a research center, which exemplifies the approach that the Carroll et al., article calls for. I hope that CEES will be among the melting pot of centers and other institutions that become involved in our Norway Project. I am not criticizing Prof. Saetre as a person. If only his position was confined to himself! Instead, it is deeply systematic of many evolutionary biologists, who for no good logical reason get sweaty palms at the prospect of going beyond genetic evolution. Unless their reluctance is overcome, using evolution to address global challenges will remain an unfinished synthesis.