Evolution educators are united by a deep sense of purpose about the need to support the public understanding of evolutionary science. Despite this widespread agreement, there is one area in which evolution educators are somewhat divided. There remains significant disagreement over the question of if and how classroom teachers should engage students in understanding the role of our human sense of purpose in evolutionary processes. We want to briefly outline the challenge here and open a discussion about a possible avenue for addressing this persistent challenge.
One of the first things evolution educators learn is that, when it comes to the evolution of the biological species on our planet, there is no pre-defined endpoint, no ladder that goes from low to high, humans are not the pinnacle of creation, and in all of these ways, evolution has no purpose. Evolution is merely the selection of heritable variation over time. This is all true and important in many respects, yet it abstracts out a deeper truth that may be obscuring important causal dynamics in evolutionary processes and may result in the seemingly endless public relations problem that evolution science appears to have within the public sphere (see Brem et al 2003).
Simply put, purpose evolves. Goal-directed behaviors and the cognitive processes that underpin them can be highly adaptive. Ever since ancient bacteria stumbled upon the capacity to move towards favorable or away from unfavorable environments, many organisms have evolved more and more elaborate capacities for goal-directed behavior. In our particular lineage as species capable of symbolic thought, we have evolved a still more elaborated capacity to develop and make explicit our goals, values, and sense of purpose in the world, allowing us to move towards imagined and distant futures. This much is uncontroversial at the level of scientific discourse, but if or how educators should engage students in general education classrooms on these points is less than clear.
A concrete area of evolution education research and practice in which this point can be made clear is that of teleological reasoning. Teleology, from the Greek telos for “end”, “purpose”, or “goal”, is a perspective that organisms or traits exist by virtue of their function. Statements such as “birds exist to fly” are clearly not scientific causal explanations of how birds got here. For that reason, biology has been in a centuries-long pursuit to advance explanations free of teleological reasoning, instead focusing on antecedent causes – causal factors that precede the phenomena to be explained (see Corning 2014 for extended historical discussion).
In teacher education and evolution education research, this often gets reduced down to the notion that “students tend to reason teleologically” and therefore “the role of educators is to correct such errors”. This sometimes results in the perception that any reference to the needs or goals of an organism is to be forbidden in a scientifically adequate evolutionary explanation. Take the research of Bravo & Cofré (2016). In this study of classroom educators’ practices for addressing teleological reasoning, the researchers highlight one teacher’s approach of having students create and read aloud their own evolutionary explanations of a given trait, and the other students are instructed to “boo” whenever their peer uses the word “need” in the explanation. That is, if a student described that a trait evolved because organisms in a population needed it to survive better, this would be viewed as wholly incorrect and deserving of peer mockery in the form of “boos” from the other students.
Now, it is technically not scientifically adequate to simply state that a trait evolved “because of a need”, such an explanation lacks explicit reference to the sources of variation and mechanisms of selection at the population level. However, as we have argued in our recent preprint article (Hanisch & Eirdosh 2020a), evolution education researchers may be jumping the gun by assuming such statements from students reflect truly flawed thinking. Instead, we point to the fact that students are rarely if ever given the opportunity to learn about the role of goal-directed or purposeful behaviors in evolutionary dynamics.
Instead of banning all teleological reasoning from student explanations of evolutionary change, we instead argue that students need tools to assimilate the role of purposeful behaviors in evolutionary processes with their intuitive understanding of the role of purposeful behaviors in everyday life.
Environments produce constraints or contexts that determine the adaptive function of any given trait or behavior. Evolution often produces organisms capable of goal-directed behaviors rooted in evolved motivations, preferences, or (in the case of humans) verbally reflected purposes that motivate responses to the perceived needs imposed by the environment (Aunger & Curtis 2015; Mitchell 2020). Such goal-directed behaviors often have fitness consequences for individuals or groups, and therefore function as important aspects of selection pressure within a given population. This again is not at all controversial among even the most mainstream of evolutionary biologists, and yet this nuanced role of goals and purposes in evolutionary processes remains far from the mainstream research agenda of evolution education.
One part of the problem may have been introduced with Ernst Mayr’s famous distinction between proximate and ultimate causes. Proximate causes are meant to describe how a trait works, that is the specific mechanisms operating at the moment, and ultimate causes are meant to describe how a trait evolved, through such processes as random variation and natural selection. This has tended to be interpreted into evolution education guidance implying that, in the search for evolutionary explanations of traits, proximate mechanisms have little or no role to play – and if students refer to such proximate mechanisms, including goal-directed behaviors of organisms, they are committing an error in reasoning. However, recent thinking about this proximate-ultimate distinction (e.g. Laland et al., 2011) have clarified the complex causal interdependence of proximate causes as drivers of ultimate causes over differing timescales. For students to intuitively assume that organisms have goals and respond to perceived needs is not fundamentally incompatible with an evolutionary explanation. The fact they are generally not given the opportunity to resolve this intuitive understanding with the scientific perspective, and instead judged (and perhaps often graded) as having naive unscientific ideas is, in our minds, an untenable situation.
The consequences of this missing causal component of proximate goal-directed behavior in evolution education may be partly responsible for sustaining public perceptions that evolutionary views of our species are incompatible with our experiences of free will and purposeful action.
There are many other reasons for this gap between evolution science and evolution education, as we have begun to outline in our other preprints (Hanisch & Eirdosh 2020b,c). However, central to all of these reasons is the tendency in evolution education to reduce all evolutionary processes to genetic change, and a unidirectional selection of individual organisms by the environment, instead of the appropriate emphasis on the complex causes of trait development and changes in trait frequency in populations.
The difference between such gene-centered models as compared to trait-centered models may seem minute (there are, in fact, many ways that both perspectives are congruent with each other), yet when you look at the persistent challenges that evolution education has faced for decades, it may be time to take a closer look at the pedagogical implications of such emerging perspectives from the evolution sciences (Eirdosh & Hanisch 2020). Indeed, helping students understand the evolution of our human sense of purpose, and the role of purposeful action in evolutionary processes, may emerge as a central purpose of evolution education itself.
Aunger, R., & Curtis, V. (2015). Gaining control: How Human Behavior evolved. OUP Oxford.
Bravo, P., & Cofré, H. (2016). Developing biology teachers’ pedagogical content knowledge through learning study: the case of teaching human evolution. International Journal of Science Education, 38(16), 2500-2527.
Brem, S. K., Ranney, M., & Schindel, J. (2003). Perceived consequences of evolution: College students perceive negative personal and social impact in evolutionary theory. Science Education, 87(2), 181-206.
Corning, P. A. (2014). Evolution ‘on purpose’: how behaviour has shaped the evolutionary process. Biological Journal of the Linnean Society, 112(2), 242-260.
Eirdosh, D., & Hanisch, S. (2020). Can the science of Prosocial be a part of evolution education?. Evolution: Education & Outreach, 13(1).
Hanisch, S., & EIrdosh, D. (2020a). Causal mapping as a teaching tool for reflecting on causation in human evolution. https://doi.org/10.35542/osf.io/y62jw
Hanisch, S., & EIrdosh, D. (2020b). Conceptual clarification of evolution as an interdisciplinary science. https://doi.org/10.35542/osf.io/vr4t5
Hanisch, S., & EIrdosh, D. (2020c). Educational potential of teaching evolution as an interdisciplinary science. https://doi.org/10.35542/osf.io/7md3v
Laland, K. N., Sterelny, K., Odling-Smee, J., Hoppitt, W., & Uller, T. (2011). Cause and effect in biology revisited: is Mayr’s proximate-ultimate dichotomy still useful?. science, 334(6062), 1512-1516.
Mitchell, K. (2020) The Evolution of Free Will. Darwin Day Lecture 2020. The Humanist Association of Ireland. https://www.facebook.com/watch/?v=648471095910764