Introduction
In the realm of social insects, termites have long been overlooked and misunderstood. While bees and ants have captured human fascination with their industriousness and honey production, termites have been largely viewed as destructive pests. However, author Lisa Margonelli's chance encounter with a "termite safari" invitation in 2008 led her on a decade-long exploration into the fascinating world of these underappreciated creatures.
In "Underbug," Margonelli takes readers on a journey across three continents, delving into the research of termite experts and uncovering the surprising complexities of these tiny insects. From their evolution as solitary creatures to their current status as highly social organisms, termites have much to teach us about biology, ecology, and even human society.
This book challenges our preconceptions about termites and raises thought-provoking questions about their nature. Are termites best understood as individuals or as part of a larger "superorganism"? Could their unique digestive abilities hold the key to sustainable biofuel production? Might termite behavior inspire the development of advanced robotics? As we explore these questions, we'll discover that there's much more to termites than meets the eye.
The Misunderstood Termite
Termites have long been the subject of human disdain, primarily due to their appetite for wood – a material highly valued by humans. The extent of this animosity is evident in scientific literature, where nearly half of all termite-related articles published between 2000 and 2013 focused on methods of extermination.
The reason for this widespread antipathy is clear: termites cause an estimated $40 billion worth of property damage globally each year. From electrical poles and railway trestles to clapboards and bridges, these tiny creatures have an insatiable appetite for wooden structures. In some cases, they've even been known to devour currency, as evidenced by incidents in India and China where termites consumed significant amounts of paper money.
What makes termites such a formidable force is not just their appetite, but their sheer numbers. Collectively, termites outweigh humans by a ratio of ten to one, making them a truly ubiquitous presence on our planet.
The story of termites begins 250 to 155 million years ago when they evolved from their cockroach ancestors. Unlike their solitary forebears, early termites developed a crucial adaptation – their guts became home to microbes capable of digesting wood. This evolutionary leap gave termites access to an abundant food source, providing them with a significant advantage.
However, this adaptation came with a challenge. Termites frequently molt, replacing their guts and losing these precious microbes in the process. The solution to this problem marked a turning point in termite evolution: they began exchanging a mixture of feces, microbes, and wood chips (dubbed "woodshake") among themselves. This practice allowed them to preserve their gut bacteria across generations and led to the development of their highly social nature.
Over millions of years, termites refined their abilities and spread across the globe. Today, there are over 3,000 named species of termites, inhabiting a wide belt around the Earth's equator and extending halfway towards both poles. Their ability to digest wood has been their evolutionary trump card, allowing them to travel across oceans in hollow tree trunks and establish footholds in diverse environments.
Termites as Mirrors of Human Society
Throughout history, humans have had a tendency to view social insects, including termites, as reflections of their own societies. This anthropomorphic perspective has significantly influenced how these creatures have been studied and understood.
In early modern Europe, as scientific observation gained prominence, people began to look to nature for answers about how the world worked. This led to increased interest in studying insect colonies, including those of termites, ants, and bees. However, the first scientists to examine these insects did so through the lens of human social and political structures.
Initially, observers saw rigid hierarchies within insect colonies, mirroring the monarchies and class systems of their own societies. They identified what they believed to be kings at the top, aristocrats in the middle, and laborers and soldiers at the bottom. It wasn't until the 1670s that this notion of male rule in insect colonies was challenged. Dutch anatomist Jan Swammerdam, using a microscope, discovered that the supposed "kings" actually had ovaries and were, in fact, queens.
Despite this revelation, the tendency to view insects as miniature versions of human society persisted. In 1781, English naturalist Henry Smeathman presented a report to the Royal Society on termites he had studied in West Africa. He drew parallels between termite society and English society, comparing the termite "gentry" to the English aristocracy, describing both as "worthless" and living off the labor of others. Interestingly, Smeathman didn't see this as a criticism but rather as a natural order of things.
The 19th century saw social insects being used to justify various ideologies. Some scientists used observations of lighter-colored ants seemingly keeping darker ants as slaves to argue for the "natural" basis of slavery and racism. On the other hand, Russian zoologist Pyotr Kropotkin saw in insect colonies a model for a cooperative and egalitarian utopia, as described in his 1902 book "Mutual Aid."
By the 1970s, when American biologist Deborah Gordon began studying ant colonies in the American Southwest, the metaphor had shifted again. Now, social insects were being compared to assembly-line workers in postwar factories, endlessly repeating simple tasks. Gordon urged her peers to abandon these unhelpful analogies, arguing that they obscured the true nature of these insects, which were fundamentally unlike humans.
However, even Gordon couldn't resist the allure of metaphor entirely. While rejecting the factory worker analogy, she proposed a new one: ants, she suggested, were like neurons firing through the human brain.
This historical perspective highlights how our understanding of social insects, including termites, has often been colored by our own societal structures and ideologies. It underscores the importance of approaching the study of these creatures with an open mind, free from preconceived notions based on human society.
The Evolutionary Puzzle of Termite Sociality
When examining an individual termite, one might be underwhelmed. These creatures, about the size of a fingernail clipping, with bulbous, eyeless heads and translucent bodies, appear rather unimpressive in isolation. However, to truly understand termites, one must look beyond the individual and consider their remarkable social structure.
Termites are classified as eusocial insects, a term biologists use to describe the highest level of sociality known among animals. This classification is characterized by two main features: collective child-rearing and a division of labor between fertile and non-fertile "castes."
At the heart of most termite colonies is a queen and her mate, often referred to as the king. The queen's primary role is to lay eggs, which she does at an astonishing rate of up to one every three seconds. Most of these eggs are coated with a chemical that prevents the termites from reaching sexual maturity. Instead of reproducing themselves, these non-fertile termites become either "workers," responsible for maintaining the colony, or "soldiers," tasked with protecting it.
This social structure presents an intriguing evolutionary conundrum. According to Darwin's theory of evolution, natural selection favors individuals who are adept at reproducing. The fittest individuals, in evolutionary terms, are those who have the most offspring. However, in termite colonies, only the queen and her mate engage in reproduction. So how do the non-fertile termites evolve?
Two main theories have been proposed to explain this apparent paradox. The first, associated with American biologist William Wheeler's work on ants in the early 20th century, suggests that we should view the entire colony as a single individual from an evolutionary perspective. This "superorganism" theory posits that the colony as a whole reproduces through altruistic behavior and evolves as a single unit or "body."
The second theory, proposed by English biologist William D. Hamilton in the 1960s, is known as inclusive fitness. This theory argues that altruism makes evolutionary sense when individual organisms sacrifice themselves for genetically similar organisms. To illustrate this concept, consider a scenario where a brother saves his sister's life, allowing her to have children who will share a quarter of his genes. From an evolutionary standpoint, this strategy is successful if the sister has at least twice as many children as the brother would have had – a feat easily accomplished by insect queens.
While Hamilton's inclusive fitness theory is currently more widely accepted in the scientific community, some termite researchers are beginning to revisit the superorganism concept. This ongoing debate highlights the complexity of termite social structures and the challenges they pose to our understanding of evolution.
The Living Architecture of Termite Mounds
Termite mounds are not merely static structures; they exhibit behaviors reminiscent of living organisms. This becomes apparent when observing termites in different contexts. A single termite in a petri dish will wander aimlessly, but a group of 40 will form a purposeful herd, circling the dish. When thousands of termites are placed in a large container with mud, they begin constructing surreal structures that, in nature, can reach heights of 8 to 30 feet.
The interior of a termite mound is a complex network of tunnels and stairs leading to subterranean chambers and galleries. Many scientists believe that the construction process is guided by a "cement pheromone" present in the termites' saliva. When one termite deposits its mud ball, the scent signals to other termites where to place theirs. As this process continues, the signal intensifies, and these stacks eventually form walls or pillars. The scale of this construction is impressive: over the course of a year, an 11-pound termite colony can move approximately 64 pounds of dirt and 3,300 pounds of water.
For a long time, it was assumed that termite mounds functioned as chimneys to cool the underground nest. However, this understanding was challenged by American physiologist J. Scott Turner's research. By pumping propane gas into a Namibian termite mound and tracking its movement, Turner discovered that mounds don't act as chimneys but as lungs. They move oxygen down into the nest and draw carbon dioxide up and away from the base of the mound.
Turner's choice of the term "lung" is deliberate and reflects his broader theory about termite mounds. He views termites not as mere inhabitants of their mounds, but as part of an interlocking, living organism. This organism, according to Turner, is physiologically self-regulating and even capable of its own kind of "thought," as evidenced by the complex building process.
While Turner's extended organism theory isn't widely accepted in the scientific community, he's not the first researcher to draw such conclusions. In the early 20th century, South African naturalist Eugène Marais developed a similar perspective, describing termite colonies as "composite animals." In Marais's view, the mound's external structure functioned as a kind of "skin," while its tunnels formed an "immune system," rushing termites (likened to blood cells) to defend the body when attacked. The queen, in this analogy, was seen as an "ovary" – the source of the body's fertility.
These perspectives challenge us to reconsider our understanding of termite mounds. Rather than seeing them as simple structures, we're invited to view them as complex, living systems that blur the lines between individual and collective, between structure and organism.
The Fungal Farms of African Termites
In the vast fields north of Windhoek, the capital of Namibia, one encounters an impressive sight: enormous termite mounds built by the Macrotermes genus. These structures are not only massive but also precisely oriented, each inclining at exactly 19 degrees from north – the position of the sun at this latitude. This uniform orientation suggests a remarkable spatial awareness among these termites.
However, as impressive as these above-ground structures are, it's what lies beneath the surface that truly showcases the ingenuity of these insects. Beneath and around Macrotermes mounds are hundreds of small chambers, each containing a comb-like structure made from chewed grass and wood. For over 30 million years, these termites have been cultivating a specific fungus called Termitomyces within these structures.
The process begins when the termites inoculate the plant material with the fungus. As the fungus grows, it spreads along the comb in branch-like spores. This fungal growth serves a crucial purpose: it breaks down cellulose and lignin – complex sugar structures found in plant cell walls – into simpler sugars that the termites can digest. In essence, the termites have developed a sophisticated method of outsourcing part of their digestion to another organism.
This relationship between the termites and the fungus is symbiotic, meaning that both parties depend on and benefit from each other. While some termites harvest the sugar-rich crop at the bottom of the combs, others are busy "feeding" the fungus with more dry grass and wood at the top. This continuous cycle ensures the survival and prosperity of both species.
The interdependence between Macrotermes and Termitomyces is so profound that it's challenging to determine which organism is truly in control. While we might instinctively assign a higher status to the animate insects over the inanimate fungus, some scientists hypothesize that the fungus might actually be using chemical signals to direct the termites' mound-building activities.
While this hypothesis remains unproven, there's no doubt about the effectiveness of this arrangement. According to Namibian farmers familiar with these termites, each mound – which contains about 11 pounds of termites – consumes as much dead grass as a 900-pound cow. This comparison vividly illustrates the incredible efficiency of the termite-fungus partnership.
In the context of the mound as a living structure, this fungal cultivation system can be likened to a giant boiler room and canteen combined. It provides both energy and sustenance for the mound's "residents," further reinforcing the idea of the termite colony as a complex, living superorganism.
This remarkable adaptation demonstrates the innovative ways in which termites have evolved to maximize their resources and survival capabilities. It also highlights the complex interdependencies that exist in nature, challenging our understanding of ecological relationships and the boundaries between different forms of life.
The Potential of Termite Gut Microbes in Biofuel Production
Modern scientists have learned to appreciate termites for what they truly are, moving beyond the anthropomorphic projections of their predecessors. When they examine termite mounds today, they no longer see reflections of human social structures. Instead, they recognize the unique biological marvels that termites represent. One area where termites show particular promise is in the field of sustainable energy production.
The key to this potential lies in the termite's gut. Termite digestive systems contain hundreds of species of microbes that enable them to convert wood and dead plant matter into energy. What makes these microbes especially interesting is their uniqueness – approximately 99 percent of these microorganisms are found nowhere else in nature except in termite stomachs.
Understanding how termite guts function could have far-reaching implications for human society, particularly in the realm of energy production. The U.S. Department of Energy estimates that the United States could produce 1.3 billion tons of dry biomass – including trees, straw, and grass – annually without reducing its current agricultural output. If this biomass could be converted into energy using methods similar to those employed by termites, it could yield about 100 billion gallons of biofuel, nicknamed "grassoline." Such a development could lead to an 86 percent reduction in current vehicular emissions, representing a significant step towards more sustainable energy use.
The quest to unlock the secrets of termite digestion took a significant leap forward in 2004 when a team of scientists at the University of California, Berkeley developed a process called metagenomics. This technique allowed researchers to sequence the genes of entire microbial communities. In 2007, the science journal Nature published the results of a metagenomic analysis of a Costa Rican termite's gut. The study identified 1,000 genes that might be responsible for wood digestion, sparking hope that the era of grassoline was just around the corner.
The U.S. Department of Energy's Joint Bioenergy Institute (JBEI) made considerable progress in this field, successfully developing a viable biofuel and reducing its production cost from an initial $100,000 per gallon to about $30. However, this was still not economically competitive with conventional gasoline, and efforts to further reduce costs have stalled.
A physicist at JBEI explained the challenge to the author. The institute's approach involved taking bacteria like E. coli, which naturally have no interest in producing biofuels, and forcing them to do so. Moreover, the cells used in these studies seemed to have a kind of memory of their past metabolic processes. This information wasn't encoded in their DNA but appeared to be stored elsewhere in their chemistry. Deciphering this code and fully understanding how termite gut microbes function remains the final frontier in the quest for affordable biofuel.
The potential of termite-inspired biofuel production illustrates how studying these often-overlooked insects could lead to groundbreaking advancements in sustainable technology. It also underscores the complexity of natural systems and the challenges involved in replicating or harnessing them for human benefit.
Swarm Intelligence: Lessons from Termites for Robotics
Imagine constructing a skyscraper like the Empire State Building without any central planning, architectural blueprints, or even basic engineering knowledge. It seems impossible, doesn't it? Yet, this is precisely what termites achieve when building their impressive mounds. This feat of collective construction, accomplished by creatures with minimal individual intelligence, offers fascinating insights into swarm intelligence – a concept that's increasingly influencing the field of robotics.
Termite mounds are products of swarm intelligence, a phenomenon where complex behavior emerges from the interactions of many individuals without any centralized control. But how exactly does this work?
Scientists favor a theory called stigmergy to explain this process. As mentioned earlier, termites are believed to deposit a "cement pheromone" on their mud balls, which guides other termites on where to place theirs. However, the process is more intricate than it initially appears. During construction, some piles of mud balls evolve into walls, while others don't. Even more intriguingly, some completed walls are later demolished. This suggests the presence of multiple pheromones triggering different behaviors.
These various triggers collectively form a simple set of rules. One scent might instruct a termite to drop its mud ball, another to keep moving, a third to remove a mud ball, and so on. Biologists find this theory appealing because it explains how relatively simple creatures can accomplish highly complex tasks without direct communication or coordination.
The concept of stigmergy isn't just useful for understanding termite behavior – it's also proving to be a valuable template for roboticists. Radhika Nagpal and her team at Harvard University's Wyss Institute for Biologically Inspired Engineering have applied these principles in developing a robot called TERMES. This robot is equipped with "wheel legs" and claw-like hands for moving objects, and it uses sensors to respond to external stimuli. These stimuli trigger algorithmic rules, much like how scents are believed to guide termite behavior.
When working collectively, individual TERMES robots can construct elaborate structures without any central command, much like termites. The only information they need is embedded in their environment. When two robots encounter each other, one simply stops and waits for the other to move before resuming its pre-programmed task. Nagpal refers to this as "extended stigmergy."
This approach suggests a potential future direction for robotics. Rather than developing a single, hyper-intelligent machine as often depicted in science fiction, we might instead see swarms of relatively simple machines working together to perform complex tasks. Each individual unit might be "dumb," but collectively, they could demonstrate remarkable intelligence and problem-solving abilities.
The parallels between termite behavior and these robotic systems highlight the valuable lessons we can learn from nature. By studying how termites build their complex structures without centralized planning, we can develop more efficient and adaptable robotic systems. This biomimetic approach – imitating nature's solutions to solve human problems – could lead to significant advancements in fields ranging from construction to disaster response.
Moreover, this concept of swarm intelligence challenges our traditional notions of intelligence and problem-solving. It suggests that complex problems don't always require complex individual units to solve them. Instead, the interaction of many simple units following basic rules can lead to surprisingly sophisticated outcomes. This insight could have far-reaching implications not just for robotics, but for our understanding of collective behavior and decision-making in various contexts, from organizational management to urban planning.
Conclusion: The Underappreciated Wonders of Termites
As we conclude our journey into the fascinating world of termites, it's clear that these tiny creatures are far more remarkable than most of us ever imagined. From their evolutionary history to their potential role in shaping future technologies, termites continue to surprise and inspire scientists across various disciplines.
Termites evolved from cockroaches between 250 and 155 million years ago, developing the unique ability to digest wood thanks to the microbes in their guts. This adaptation led them to become highly social creatures, forming large colonies with complex structures and behaviors. For centuries, humans have been fascinated by these insect societies, often projecting their own social and political ideas onto them. However, it's only in recent decades that scientists have begun to study termites on their own terms, free from anthropomorphic biases.
This shift in perspective has revealed the true wonders of termite colonies. We've discovered their remarkable architectural skills, evidenced by the massive, precisely oriented mounds built by species like Macrotermes. These structures aren't just impressive in size and shape; they function as living, breathing entities, regulating the internal environment of the colony with astonishing efficiency.
We've also learned about the sophisticated "agricultural" practices of some termite species, which cultivate fungal gardens within their mounds. This symbiotic relationship between termites and fungi showcases the complex interdependencies that can evolve in nature, challenging our understanding of ecological relationships.
Perhaps most excitingly, termites might hold the key to solving some of humanity's most pressing challenges. The unique microbes in termite guts could potentially revolutionize biofuel production, offering a sustainable alternative to fossil fuels. If we can unlock the secrets of how termites break down cellulose so efficiently, we might be able to produce affordable, environmentally friendly "grassoline" on a large scale.
Furthermore, the way termites work together to build their complex structures without any central coordination is inspiring new approaches in robotics. The concept of swarm intelligence, as demonstrated by termites, could lead to the development of robot swarms capable of tackling complex tasks in construction, disaster response, and other fields.
As we face global challenges like climate change and resource scarcity, the lessons we can learn from termites become increasingly valuable. These tiny insects demonstrate remarkable efficiency in resource use, adaptive capabilities, and collective problem-solving – all qualities that human societies desperately need to cultivate.
In the end, "Underbug" invites us to reconsider our relationship with the natural world. Termites, long seen as pests to be eradicated, emerge as complex, fascinating creatures with much to teach us. Their societies, while alien to our eyes, offer alternative models of organization and cooperation that could inform our own societal structures.
Moreover, the story of termite research reminds us of the importance of approaching scientific study with an open mind. By shedding our preconceptions and anthropocentric biases, we open ourselves up to truly revolutionary discoveries.
As we continue to explore the intricate world of termites, we're likely to uncover even more surprises. These underappreciated insects, it turns out, are not just wood-eating pests, but windows into the marvels of evolution, ecology, and collective behavior. They challenge us to think differently about intelligence, society, and our place in the natural world.
In a time when humanity faces unprecedented environmental and social challenges, the humble termite offers us valuable lessons in sustainability, cooperation, and adaptation. Perhaps by paying closer attention to these tiny "underbugs," we can find innovative solutions to some of our biggest problems. The termite, it seems, has much more to offer us than we ever imagined – if only we're willing to look closely and learn.