Culture and the Course of Human Evolution
by Gary Tomlinson

Reviewed by Kevin C. Moore

In an academic age where interdisciplinarity can seem an implicit virtue, the application of STEM ideas to explain human phenomena has become a dominant epistemological shift. This is, often, a salutary trend. The rise of fields such as evolutionary psychology, for instance, have opened compelling new frameworks for understanding human behavior. Ecocriticism, too, constitutes a concerted and salutary reaching across disciplinary lines, a contribution to the effort to understand our response to, and responsibility for, the geological and evolutionary era now frequently called the Anthropocene. Yet scientific explanations for human questions always pose the risk of taking on deterministic overtones, and it is also the case that when scientific explanations cross into the humanities, there is the risk that the nuances of complex realities may be lost, or that human prejudices may look to find confirmation in the wilderness of scientific results.

Take social Darwinism and its notion that our genetic identities dictate our actions. Despite the cautionary tales of twentieth-century atrocities involving eugenics, the rising visibility of epigenetics—the study of gene expression, and of how changes to gene expression that occur during the life of the individual can be inherited—of late has proven fertile terrain for advocates of the discredited concept. If a group can be proven to have been epigenetically impacted by historical conditions, hate groups interpret that as confirmation for their arguments (deep-Google “epigenetics” at your peril). Of course, no such explanation emerges from actual epigenetics research, an exquisitely subtle field, as anyone familiar with the actual science will tell you. But slippage can—and often does— occur in popular discourse, when intriguing scientific methods and findings are incorrectly applied to fields to which they are not directly applicable.

Gary Tomlinson, the John Hay Whitney Professor of Music and Humanities at Yale, offers an important corrective to this problem in Culture and the Course of Human Evolution (2018), a multidisciplinary project that seeks to remind humanists that human cultural developments are not detached from an evolutionary past, while, at the same time, recognizing that evolution involves the transmission of information via a range of media, which are not simply genetic or epigenetic but just as often cultural and environmental. Author of the acclaimed A Million Years of Music (2015), Tomlinson has now spent years studying the most recent developments in evolutionary biology, where it is “not enough for us [humanists] to dabble.” Culture, the product of this work, explores not only what some of the most important recent developments in evolutionary studies have to offer our humanistic understanding of human culture, but also what various methods and ideas from the humanities might offer science as well. Deliberately dwelling in the “straits separating science and the humanities,” Tomlinson asserts that evolutionary history is ultimately just that: history. Which is to say that it is as much a discipline of the humanities as of the sciences. For histories, Tomlinson argues, “will not reveal their secrets on the experimenter’s lab table,” but rather through the detailed descriptive research methods scholars of the humanities depend upon. In Tomlinson’s view, evolutionary history is a grand transmission of information –throughh a complex network of genes, culture, and the environment—a great, indeed the greatest, “archive,” and one that his work proposes to read.

Ultimately, as with all discussions of evolution, the fundamental concept underlying Tomlinson’s analysis  is that of emergence, which, to quote Wikipedia, "occurs when an entity is observed to have properties its parts do not have on their own." Water, for example—an aggregate of H20 molecules—has the emergent property of wetness, which is not a property of individual H20 molecules. Tomlinson’s focus is on the emergence and course of human evolution, and so as one illustration of emergence in action he uses the example of a spear. The spear, he points out, is a tool whose component parts—the point, shaft, and binding apparatus—have nothing to do with one another, but taken together constitute a novel and useful technology. Only transgenerational education makes the knowledge of how to create a spear possible. The question of how to study emergent phenomena is, for Tomlinson, perhaps the most important one to consider, since emergence is a field rife with possible error. We need to be especially vigilant, Tomlinson warns, to remember that, at least as concerns human affairs, emergence is a historical matter. The spear is not simply a random or accidental new phenomenon, but the product of a shift in either the “behavior or operation” of the larger system in which the spear’s hithertofore component parts had no means to come together.

(This call to vigilance has implications for how we think about technological prognostication, and for that matter about science fiction. We should not be surprised, for instance, that AI looks not like the Terminator but like the utterly familiar: a news story curated by algorithm for our interest on Facebook, which is a feedback system dependent upon the behavior of our willful participation.)

The persistence of systematic artifacts that archaeologists can study to “read” the past depend upon the material they are made from: spoken words vanish as soon as they are uttered; wood and other plant matter decays relatively quickly. Some archaeological evidence, however, persists; mainly items made of stone. In examining spears and other early human tools, while the functional differences between primitive cutting tools can seem immaterial to the retrospective modern human eye, degrees of nuance in toolmaking practices are discernable, and a surprising amount can be learned from primitive instruments. Oldowan stone choppers, for instance, which are about 2.7 million years old, do not reflect systematic knowledge or standardized procedure, even though the basic technique for flaking cores was clearly passed down by imitation, and cognitive processes dependent upon indexical rather than symbolic reasoning. The Levallois technique mastered during the Middle Paleolithic period (200,000-300,000 years ago), on the other hand, clearly depends upon a technique with distinct stages, and thus on a complex system of symbols to transmit that technique to others.

Tomlinson’s work is a survey of the course of human evolution, and the ideas of evolutionary biology form the backbone of Tomlinson’s account. The modern conception of evolution, referred to as the Modern Synthesis, emerged in the 1930s, and is a fusion of Mendelian genetics with Darwinian evolution. Contemporary "Mendelian" genetics accounts for the ways in which the information to build individual organisms is encoded in the genetic material (DNA). Darwinian evolution is the idea that the individuals best fit to their local environment are also those most likely to pass on that genetic material. For each generation, those genes that promote reproduction are selected for, and those whose carriers are unable to reproduce are selected against. While many are familiar with the main ideas of the Modern Synthesis, Tomlinson also introduces his reader to key evolutionary concepts such as coevolution (when two species mutually impact each other’s evolution), niche construction (where a system of environmental feedback provides accelerating evolutionary advantages), and emergence (the arrival of novel evolutionary phenomena). The evolutionary model provided here depends upon “major-transition theory,” which John Maynard Smith and Eörs Száthmary advanced as an update to Stephen Jay Gould’s older notion of “punctuated equilibrium.” In both models, evolution takes place gradually but with periodic bursts of rapid change. But for Maynard Smith and Száthmary the focus is on the handful of major transitions that have occurred during the history of life on earth, “very large, important punctuations” that entirely change not only lifeforms but the mechanics of evolution itself (such as the arrival of sexual reproduction).

So much for the transmission of information via genes. Presumably the reader will also be familiar with the notion of the transmission of information via other media (memories, print, images, etc.) as well. But what about the transmission of information via our environment? To generalize, information is “what is conveyed or represented by a particular arrangement or sequence of things.” For example, a truly random sequences of 1s and 0s is noise. A sequence of 1s and 0s arranged in a meaningful order is information. Along these same lines, just as the information contained in DNA alters the way our genes construct our bodies, in just such a way “niche construction”—the arrangement of the matter of one’s physical environment—encodes in the physical world information that changes the way we interact with it. Prehistoric cavemen and modern city dwellers interact very differently with the world around them, and the instructions that encode those differences in behavior are written, at least partially, into the built environment around us. We exist with our built environments in system of “feedback.” This is of course true for animals and other forms of life just as it is for humans.

Tomlinson’s analysis of the nuances of information transmission across media—genetic, linguistic, environmental—is built upon the semiotic work of Charles Sanders Peirce. Peirce may be the most influential nineteenth-century American thinker who most Americans have never heard of. A co-founder, with William James, of the philosophical school of Pragmatism, Peirce was also a prolific scholar in the fields of semiotics and logic. Of all Peirce’s concepts, the one most important to Tomlinson here is Peirce’s distinction between different categories of sign: icon, index, and symbol. Tomlinson takes these categories and maps them onto evolutionary history so as to demarcate pivotal transitions in the history of culture.

According to Tomlinson, many animals make use of icons, which are signs that encode a qualitative resemblance between the sign and what it represents. An icon, put differently, looks like the thing it is signifying. A bird identifying a particular berry on the basis of its appearance does so “iconically”; for us, a jumping deer on a street sign—signaling a deer crossing area—would be an iconic resemblance. An index is a more complicated manifestation of sign, requiring the processing of associative, usually historical knowledge of a causal relation. An index, in other words, shows evidence of what it is representing. The presence of smoke, for example, is interpreted as indicating that fire is close by. Indexical knowledge emerges from some kind of learning experience, whether individual or passed down through education from other species members. Some animals are capable of indexical cognition, such as a cat who knows that the sound of a shaken bag of food signifies dinner will shortly arrive. But the cat has no way of transmitting that information to its offspring, who must experience it for themselves. Finally, in a symbol, the most complex form of sign on Peirce’s hierarchy, one no longer finds any obvious relation between what Saussure would later call the signifier and the signified, the two only relating now through systems of rules and conventions, which are a necessary background for understanding its meaning. A traffic light, for example, or the Nike swoosh, are symbols.

For Tomlinson, symbols are almost the exclusive domain of Homo sapiens. But whereas many theorists of culture and evolution may focus their search for glimpses of symbolic cognition in animals, the more interesting question for Tomlinson is tracing what he calls “hyperindexicality,” the pre-symbolic situation where indexical signs break their seeming boundaries. If cats found ways to simulate shaking sounds while their kittens were dining, to call attention to the indexical relationship between the phenomena of shaking and food, the situation would certainly be hyperindexical. While we may not observe this particular behavior in cats, we do know that cats are capable of creating sounds that tap into the same empathy pathways that trigger human concern for infants of their own species, which is another clear example of an indexical sign leaping forward in the direction of symbolic communication. The development of increasingly complex systems of hyperindexical behaviors like this were, for Tomlinson, exactly the phenomena that early humans participated in when they performed proto-rituals resembling, but not yet becoming, music, dance, and language.

Tomlinson’s explorations, though offering few conclusive answers, are rich and compelling. Culture and the Course of Human Evolution offers a series of novel questions, with implications that reach to bedrock ideas of humanist inquiry. Tomlinson begins with the questions evolutionary theorists presently wrestle with, and extends them to human culture in its historical context, enriching his process with his humanist historical method. The approach is a deliberately messy one, as Tomlinson regularly warns, because “[u]nderstanding complex histories is like digging in loose sand: each deepening of insight brings a tumble of new questions all around.” How does the environment serve as a medium for transmitting biological and cultural data? What did language and culture look like on the threshold of spoken languages and history? What are the conditions of emergence for phenomena that are at once genetic, cultural, and environmental? Humans, and other species, and the planet itself, are a part of complex systems without their knowledge. A true Foucauldian “founder of discursivity,” Tomlinson’s questions are presented as sites for further inquiry, including what may be the biggest question of all: how did modern human behavior “click into place without physical transformations noticeable in the fossil record?” How did it happen so quickly, so that, as Tomlinson aptly puts it, “in a blink of the earth’s eye, they were transformed”?

In 1990, science-fiction author Terry Bisson published a short story called “Bears Discover Fire,” which nicely emblematizes the popular conception of emergence. The plot is contained in the title—bears are spotted in highway medians enjoying the warmth of campfires. But, as with most science-fiction, the implications for “real” human life are the most interesting aspects of the story. From a Tomlinsonian point of view, Bisson’s vision of sudden evolutionary emergence ultimately practices an exercise in anthropocentric historical vanity. They suppose that further evolutionary emergence will occur in a configuration that is currently imaginable to us. But that’s not how major-transition evolution, or for that matter emergence takes place. Unlike science fiction, emergence is unimaginable until it is made manifest. Evolution, including human evolution, is neither unsubtle, nor unsystematic, nor over. If we wish to better understand it and get some glimpse of where we may be headed, our best path may be to return to the archive of life, documenting in context historical instances of hyperindexicality and emergence.