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In Purpose and Desire, Scott Turner Argues that Cognition Is Foundational to Life


In a previous article, Ann Gauger described how J. Scott Turner identified homeostasis as the foundational principle defining life in his new book Purpose and Desire: What Makes Something “Alive” and Why Modern Darwinism Has Failed to Explain It. Homeostasis represents persistence of form—the driving tendency of life to maintain itself in a state of dynamic disequilibrium with the outside world. As one example, the internal conditions of any organism from a simple cell to a complex animal are maintained within tightly controlled ranges of such factors as temperature, pH, and concentrations of essential chemicals. Homeostasis must persist even in dramatically varying external conditions, else the organism dies and decomposes back into simple chemicals. Today’s article will focus on what Turner describes as the flipside of homeostasis, which is cognition.

Turner sees cognition as an essential feature of life, and it leads to intentionality. He does not define these concepts in the sense of thinking about what one wishes to do on holiday. Instead, he describes cognition as forming a mental image of the outside world and intentionality as the resulting actions. More specifically, organisms maintain homeostasis through self-adjustments and interactions with the outside world, which can include reshaping the surrounding environment:

Cognition involves forming a coherent mental image of the “real” world, and the coherence of that mental image depends upon a homeostatic brain. Intentionality is the obverse of this: intentionality is the reshaping of the real world to conform to a cognitive mental image. This also depends upon a homeostatic brain. In short, all homeostasis involves a kind of wanting, an actual desire to attain a particular state, and the ability to create that state. (p. 70)

Examples of this process abound in biology. For instance, certain species of ants actually herd aphids and mealybugs. The ants milk the bugs by stroking them with their antenna, causing the bugs to secrete a sweat substance that is a rich source of food. The ants continuously move their insect stock to new pastures and protect them from prey, so their food source remains constantly available. Even more striking, they can sense the approach of a storm before it arrives, and they respond by corralling their livestock under leaves for their protection. After the storm, they return the herd to the original location.

In contrast, other ant species create stunningly complex underground structures with separate chambers for farming fungus and collecting waste. Their cities also use distinct ventilation shafts to allow fresh air to enter and carbon dioxide to exit. The air flow is driven by differences in temperature between the waste chambers and farming chambers. The colony constantly adjusts the underground environment to ensure the proper temperature, humidity, and oxygen levels are maintained. The ants also use antibiotics to “weed” their fungal farms. A farming ant species creates a completely different image of a desired world from that of a herding species, and uses a drastically different strategy to bring its picture into being.

These differences demonstrate key points about cognition. First, the origin of a new cognitive image does not lend itself to undirected evolutionary explanations. The proposed common ancestor for the different ant species would likely have lived a simpler existence with a dramatically different image of a desired world. Perhaps it inhabited a single tunnel, and workers foraged for food in the surrounding vicinity. Evolving a complex change of behavior would require multiple new neural connections in the brain, and each would require multiple new chemical signals — or new receptors — to guide axons to new target neurons during development. The launching of new signals or construction of new receptors would require the alteration of multiple regulatory regions of multiple genes, amounting to numerous coordinated mutations. The chances of so many undirected mutations being obtained in the time allotted by the fossil record seem remote.

Additionally, individual behavioral changes toward a new cognitive mapping, in isolation, would conflict with the current cognitive mapping, since the corresponding goals would be different. For instance, ants suddenly developing the drive to follow random insects would become distracted from constructing a tunnel. As an analogy, imagine construction workers mixing up a few pages of the blueprints for a skyscraper with that of a shopping mall. The construction crew would constantly work in conflict, never effectively achieving either goal. In the same manner, the ants’ initial behavioral changes toward a new mental image would work against the original goals and be quickly selected out of the population.

For evolution to move forward, a new world image would have to come into being first, and then multiple coordinated behavioral changes would need to take place at once. In the case of herding, the ants would immediately require the ability to identify the correct species to domesticate, the drive to constantly remain close to the herd, and the ability to identify and drink the secreted liquid. The herding would require recognizing when the herd’s food was diminishing, identifying new locations with more food, and obtaining the skill to direct the herd to the new pasture. Even more challenging, protecting the herd from storms would require learning to predict the weather, identify a safe shelter, move the herd to the shelter, and recognize when conditions were safe to return to the grazing pasture. The implausibility of complex behavioral changes originating solely through natural selection acting on mutations has been recognized by leading evolutionary theorists.

A second point, which Turner emphasizes, is that cognition is not confined to individual complex animals. In the case of ants, a colony acts as a collective brain, and it maintains homeostasis between its underground city and the outside world. Conversely, cognition is demonstrated even by single cellular organisms. Biologist Lynn Margulis comments:

I’ve watched conscious bacteria for hours seeing things about which everyone would scream if they saw them. Unbelievable diversity! A microscopic theater with thousands of beings all interacting, dying, killing, feeding, excreting, and sexually provoking each other — all activities most people think are so specifically human. The idea that only people are conscious makes me laugh.

Turner adds another claim. Individual cells or organisms can have their own cognitive mappings of the world, but when they come together, they negotiate a new integrated picture, which allows them to work together. He provides several diverse examples to argue his point.

For instance, he describes how the human body maintains its temperature through interactions between multiple systems and tissues, including muscle cells, blood vessels, skin pores, and a thermostat in a small region at the base of the brain. However, the thermostat does not seem to function as the center of control. And every attempt to model temperature regulation as a system with increasing numbers of control centers failed to capture the underlying complexity. Turner concludes:

Rather than nerve cells and sensors serving as dedicated components in neural “circuits” that are wired together into a well-tuned cybernetic computer, there are innumerable little conversations, spreading of gossip and vague rumors, and the “weather” inside the brain. Individual nerve cells seem to be homeostatic agents unto themselves, capable of sensing temperature, making comparisons, and even bringing about a degree of self-maintenance of temperature on their own…There is no master thermostat; every cell is a “-stat” of some sort. The steady temperature of the body somehow emerges from the endless conversations and negotiations between these innumerable many little “-stats.” (p. 65)

Turner also discusses Margulis’s theory that the first eukaryote came about by a sulfur-consuming bacterium combining with a sulfur-producing bacterium. The challenge to this theory is that the two organisms would have had different mental pictures of the world and interacted with their environments in very different ways. After combining, the two bacteria would have acted in conflict, resulting in a highly inefficient symbiont. It would have been lost through natural selection long before random mutations would have properly integrated its architecture.

Instead, Turner argues that the two organisms would have had to negotiate a new reconciled picture of the world, and the cognitive desire to move into this new picture would have driven the organism forward.

…what exactly drives it forward? Is it the tokens of memory [DNA] that force life into an uncertain future, pushing it there to either stand or die? Or is it forward-looking intentionality that strides confidently into the future, dragging the memory tokens along in its wake, intending to stand rather than simply to die? (p. 183)

Turner’s propositions are provocative and maybe even disturbing to both traditional evolutionists and many proponents of intelligent design. However, his thesis is well-argued and needs to be examined carefully. Key points are that the evidence of purpose and design permeate life at every level, and this evidence presents ever increasing challenges to all theories of undirected evolution.

Image credit: viamoi [CC BY 2.0], via Wikimedia Commons.