Chapter Twenty-nine: A Large Web or Rather a Network, Every Living Thing

Twenty-nine

A Large Web or Rather a Network

When he can spare the time, Dr. Jan Mees is an exorcist of scientific ghosts. A marine biologist, Mees’s full-time job is directing the Flanders Marine Institute in Ostend, Belgium, but his side project is serving as co-leader of an international group of volunteer scientists. Together, they’re working to build a World Register of Marine Species, a comprehensive database vetting the accuracy of scientific names for aquatic life. It was a daunting task from the beginning, but Mees and his colleagues have been surprised by how much of their work involves not adding to the register but subtracting from it.

After analyzing 418,850 species, the project has eliminated 190,400 of them—more than 45 percent—as redundant. The species felis and Triakis semifasciata, for instance, are in fact both the leopard shark. Octopus rooseveltii, named in 1941 as a tribute to then-president Franklin Delano Roosevelt, already existed as Octopus oculifer, named in 1909. No one knows how many previous generations of marine biologists devoted their careers to studying a notional species, not realizing that their peers were studying it under different names.

One of the most prolific over-classifiers, they’ve discovered, was Louis Agassiz, who eagerly declared and named North American species based on little evidence, and even less scientific rigor. Viewing a single sample of fossilized teeth, Agassiz determined they defined not three different species but three completely new genera of fish. They’ve since been matched to teeth belonging to the fossil of a single individual fish, collapsing an entire branch of his imagined taxonomy. Hundreds of Agassiz’s species identifications have been abandoned on similar grounds.

Presently, the greatest single instance of systematist ephemerality is the case of Litteronia saxatilis, a shore-dwelling sea snail commonly known in English as the rough periwinkle. Easily found on beaches on both sides of the North Atlantic, the rough periwinkle long ago developed the ability to blend into its immediate marine environment by varying the size, the coloration, and even the shape of its shell. The mollusk inside the shell is unchanged, but two centuries of classifiers, not only focusing on external morphology but accepting empty shells as definitive type specimens, made the rough periwinkle the “champion of taxonomic redundancy,” according to Dr. Mees. Since its initial naming in 1792, Litteronia saxatilis has been identified, named, and catalogued as a separate species or subspecies no fewer than 112 times. The World Registry of Marine Species has quietly erased those identifications, retroactively updated the scientific literature to point to the original designation, and moved on.

Why so many duplications? Most are products of the Linnean emphasis on appearance, which allowed minor physical variations to be interpreted as novel species. Some constitute genuinely separate discoveries, obscured by the difficulty of reviewing printed scientific literature in the days before digitization and database searches. Still more are the results of overzealous imaginations, seeking a measure of immortality by declaring a “discovery” where none existed. To estimate how many officially designated species are mistakes or duplicates, on land as well as underwater, John Alroy, a paleobiologist at Maquarrie University in Sydney, Australia, has devised a “flux ratio,” a predictive metric extrapolated from the number of corrections already made to taxonomic data. Professor Alroy’s flux ratio predicts that ultimately, 24 to 31 percent of all current species names will eventually be discarded as redundant.

We’ve also come to realize that while some species exist under multiple names, other named species don’t exist at all. In the tenth edition of Systema Naturae, in the order Vermes, Linnaeus included the Shot, or Furia infernalis, the creature he was convinced had nearly killed him as a student in 1728. He described it as a flying worm as thin as a human hair, which

quickly buries itself under the skin, leaving a black point where it had entered; which is soon succeeded by the most excruciating pain, inflammation and gangrene of the part, swooning, and death. This all happens in the course of a day or two, frequently within a few hours, unless the animal be immediately extracted, which is effected with great caution and difficulty, by applying a poultice of curds or cheese; or carefully dissecting between the muscles where it has entered.

Linnaeus had given it scientific existence, and that had been good enough for other reports of Furia infernalis attacks to start trickling in. A priest in Lapland attested he’d narrowly avoided the bite of one, which landed on his plate. A young servant girl had not been so lucky: A Shot had bitten her finger, and she would surely have died had an onlooker not immediately amputated the infected digit. After reports of an 1823 Furia infernalis attack that killed some five thousand reindeer in Lapland, Finland imposed a ban of fur from the region in hopes of preventing its spread. No one, however, could produce a specimen. The contemporary consensus is that Linnaeus was likely bitten by a horsefly.

We’ve also been subject to a different kind of illusion: seeing one species where in fact there are several. One of the more surprising results of genomic analysis is the discovery in 2021 that the giraffe, believed to be a single species since Linnaeus named it Giraffa camelopardelis in 1758, is in fact four distinct species, genetically distinct for at least a million years. This startled zoologists, who are now rushing to reevaluate everything thought to be known about what seemed a familiar animal. “To put our results into perspective, the genetic differences between the distinct giraffe species are similar to those between polar and brown bears,” says Dr. Axel Janke, a geneticist at Goethe University. “We’ve clearly completely forgotten what a giraffe is.”

The finding has also galvanized conservationists. As a single species, giraffes were already classified as “vulnerable” on the International Union for Conservation of Nature’s list of threatened species. Now understood as separate species and therefore separate populations, at least three of the four meet the criteria for reclassification as “endangered” or “critically endangered.” “Giraffes are assumed to have similar ecological requirements across their range, but no one really knows,” says Dr. Julian Fennessey, director of the Giraffe Conservation Foundation. “It would be ignorant to ignore these new findings.”

With its imposing Palladian architecture and central courtyard, London’s Burlington House elegantly plays its role as a temple of learning. The massive three-century-old building, formerly the residence of the Earl of Burlington, now holds the Royal Academy of Arts, the Royal Astronomical Society, the Royal Society of Chemistry, and the Geological Society of London, as well as a half-dozen other learned societies under the benevolence of the Crown. In one corner, tucked away in an unobtrusive arcade of columns, is the Linnean Society.

While it retains its original name, the society has long since grown beyond its founder James Edward Smith’s vision of enshrining the Linnean worldview. It is now one of the world’s foremost centers for publishing contemporary biological research, with membership a coveted honor for biologists around the world. It deals frankly with its past, acknowledging and disavowing malign aspects of its legacy. “Linnaeus’ work on the classification of man forms one of the eighteenth-century roots of modern scientific racism,” it notes on its website. “The Linnean Society intends to confront the consequences of scientific racism.”

The society does, however, maintain a physical link to its namesake. The surviving specimens of Linnaeus’s personal collection—the ones that Smith did not auction off, give away, or simply discard—are carefully preserved at Burlington House. Access to this collection (as well as to the trove of Linnaeus’s original manuscripts that Smith received in the bargain), is limited and closely monitored. Permitted visitors are ushered into an elevator that descends into an underground complex, then led into the display area of the Strong Room, both a security vault and a fail-safe controlled environment. If the streets of London were being firebombed above (as they were in the Blitz raids of World War II), the Strong Room is so thickly reinforced that its temperature and humidity would vary by less than one degree. Here, in glass-topped drawers that slide neatly from custom-built cabinets, reside the remnants of Linnaeus’s original collection. “All the natural objects preserved in spirits of wine exist no more,” lamented one visitor in 1888. “The mammals have disappeared, the birds have flown, and the fishes slipped away, probably caused by the several removals.” But the cocoa plant (Theobroma cacao) remains, as does the slender-leaved Buffonia and the twinflower Linnea borealis. It is a singular experience, to look at a carefully curated plant or insect and know that Linnaeus once held it in his hand. And to know that (by the rules of conventional taxonomy), this particular plant or insect represents the quintessence of its species, just as Linnaeus purportedly represents Homo sapiens.

While the Linnean Society preserves these as historical artifacts, it’s ready to move beyond the limitations they’ve come to represent. A myriad of lifeforms cannot be pressed under glass or pinned to display cases. They are constantly adapting and diverging, defying our attempts to attach fixed labels. A retrospective of the society, published on the three-hundredth anniversary of Linnaeus’s birth, concluded with the statement, “Species names are not static…. The species, called by its Linnean two-word name, is a practical category for entities we wish to talk about.”

Remember that Linnaeus was a great innovator, but that not all his ideas worked or have been carried forward to today. In our attempts to come to grips with the challenges facing us and the other species with which we share the planet, it is worth reflecting on the importance of such innovation and on the necessity of looking forward and adapting our outlook as new challenges arise.

As we’ve come to realize, “the other species with which we share the planet” exist in mind-boggling numbers. Even with the elimination of duplicated or imaginary species, we’re forced to confront the fact that we’ve barely begun the tally of life’s diversity. As advances in genetics now make clear, the number of extant species—as defined by genetically distinct reproductive populations—is vastly greater than previously imagined.

How much greater? That number keeps revising upward. In 2011, the most exhaustive survey of biodiversity yet undertaken came up with an estimate of 8.7 million species, of which only 1.2 million had been catalogued thus far. That estimate meant that 86 percent of all land-dwelling species, and 91 percent of all aquatic species, remained undiscovered. Yet those numbers were dwarfed by a preliminary report five years later from the National Science Foundation. An NSF project called Dimensions of Biodiversity is using gene sequencing to identify species down to the microbial scale, and while it will take years for full results to emerge, project members already estimate the total number on Earth is more than twenty orders of magnitude greater than previously understood. “Until now, we haven’t known whether aspects of biodiversity scale with something as simple as the abundance of organisms,” reports Dr. Kenneth J. Locey, a postdoctorate fellow at Indiana University and a Dimensions of Biodiversity researcher. “As it turns out, the relationships are not only simple but powerful, resulting in the estimate of upwards of one trillion species.”

One trillion species. That would mean we’ve discovered and recorded only one one-thousandth of one percent of all possible entries in a catalogue of life.

As hard as that number is to imagine, it is harder still to imagine that many species fitting into the Linnean taxonomical hierarchy, which is already tottering to accommodate the 1.2 million species thus far identified. Extensive modifications to the system have already been adopted: Linnaeus’s original three kingdoms (animal, vegetable, mineral) have been joined by five more: fungi, chromista, protozoa, archaea, and bacteria. The original five nesting boxes (kingdom, class, order, genus, species), which Linnaeus considered perfect and complete, are usually presented as seven, with the addition of phylum (inserted between class and kingdom) and family (between order and genus). But this is the simplified version. In reality, biologists have been compelled to balloon the hierarchy to no fewer than twenty-one distinct categories.

Some taxonomists have deployed a twenty-second category, beneath the level of kingdom, although its name has not been standardized. It is variously referred to as dominion, superkingdom, realm, empire, and domain. Under any name, it is intended to accommodate our increased understanding of the diversity of unicellular life. A group of microbes called hemimastigotes, for instance, differs from other microbes as much as a chanterelle mushroom differs from a chimpanzee. To account for such evolutionary distance, the hierarchy requires augmentation beneath what has, from the beginning, been understood as its very root.

The original five levels of Linnean taxonomy, with current additional levels interspersed

Extended as it is, Linnean-based taxonomy does not include cultivars, a term coined in 1923 to describe distinctive plant varieties that nevertheless retain the genome of the original species. Pumpkins, zucchinis, and yellow squash are all cultivars of the species Curcurbita pepo. Six other vegetables commonly found in the produce section—broccoli, cabbage, Brussels sprouts, cauliflower, kohlrabi, and kale—are taxonomically the same plant, cultivars of the wild mustard Brassica oleracea. Since 1953 these have been documented separately under the International Code of Nomenclature for Cultivated Plants, which also catalogues grexes, a separate term for hybridized orchids.

And then there are viruses, classified separately by the International Committee on the Taxonomy of Viruses. There’s no consensus on where they fit in the current taxonomical system, if at all. Some biologists argue that they are not technically alive, as they have no metabolism and cannot replicate without a host. Others, pointing to recent discoveries of “megaviruses” that rival bacteria in size and genetic complexity, believe they occupy at least a border zone between life and non-life.

It is becoming pointless to add further boxes to the nesting hierarchy, further branches of kingdoms to the common trunk of life. As the philosopher Marc Ereshefsky wrote in The Poverty of the Linnaean Hierarchy, “Linnaeus’s motivation for assigning species binomial names has become obsolete. Even his sexual system and the method of logical division has been abandoned…. All that remains of Linnaeus’s original systems is a hierarchy of categorical ranks and the use of binomial names.”

It is, in fact, something of a misnomer to continue to call it the Linnean hierarchy. The existing infrastructure (including the category family, borrowed from Michel Adanson) reflects the gradual acceptance of Genera Plantarum, Antoine-Laurent de Jussieu’s rival system of plant classification. While little noted in the eighteenth century and largely ignored in the nineteenth, Jussieu’s work gained gradual acceptance throughout the twentieth century. By 1981, seventy-six of Jussieu’s classifications of botanical genera had been incorporated into standard taxonomy, while only eleven of Linnaeus’s remained. In 2005, the International Botanical Congress made the shift away from the Linnean sexual system official, moving the recognized starting point of genera names from Linnaeus’s 1753 edition of Species Plantarum (the first botanical spinoff volume of Systema Naturae) to August 4, 1789, the publication date of Jussieu’s Genera Plantarum. The present taxonomy of plants is a hybrid, one that could rightly be called the Linnaeus-Jussieu-Adanson system.

But no one is worrying about placing labels on our current system of labels. Instead, biologists are proposing and debating the contours of an entirely new system to replace it.

Can we build a system without objective bias?

Julian Huxley’s concept of cladistics, a taxonomy based on genetic diversion, seems to fit the bill, but there are complications. The boundary of cladogenesis—when one species population becomes incapable of breeding with its source species—is difficult to pinpoint, particularly in the fossil record: There is, as yet, no consistent means of identifying which aspects of genetic drift decisively affect reproduction. And reproduction itself is proving an increasingly fluid boundary. As we’ve discovered, many species have evolved means of thriving without resorting to conventional fertilization. Several kinds of salamanders and frogs are both unisexual and parthenogenic, their eggs developing without male intercession. Others survive through kleptogenesis, the “stealing” of sperm from the males of another species—a process that fertilizes the egg without incorporating the male’s genes. One spectacular instance of resourcefulness occurs in a cluster of five species of salamanders in the genus Ambystomia. Each species is unisexual, but together they form a reproductive complex, borrowing genes from one another to trigger reproduction while remaining distinct species.

Yet life is more resourceful still. We’ve also come to recognize that some species are not individual organisms but the interaction of several. Lichens, for instance, straddle two kingdoms. Linnaeus labeled lichens the rustici pauperini (poor trash) of the vegetable world, but placed them firmly in kingdom Plantae. In the late twentieth century, biologists discovered that most lichens are not a single species but a symbiotic colony of the fungus ascoycota (kingdom Fungi) and algae (kingdom Plantae). A more recent study established that at least some lichens incorporate a third organism, basidiomycete, which is a yeast. Far from being rustici pauperini, lichens display some of the most sophisticated interactions of lifeforms yet discovered.

Other boundaries in biological perception have begun to be dismantled. The blue whale, long considered Earth’s most massive lifeform, has been dwarfed by the discovery of a thirteen-million-pound organism dubbed Pando. A resident of central Utah since at least the last Ice Age, Pando is so enormous it occupies 108 acres. Yet it went unnoticed until 1976, when researchers from the University of Colorado found what appeared to be a forest of aspen trees was really forty thousand clones of the same tree, interconnected at the roots.

Pando is truly a single organism, as the clones do not propagate by seeding. Instead, when one tree begins to die it replenishes by sending signals through the root structure, and a new clone emerges. Biologists are both elated at the identification of Pando and frustrated that we failed to recognize it sooner; human incursion into its domain may have stopped its replenishment, leading to a slow decline and eventual death. While possibly the oldest organism, Pando is not the largest, although it was considered such until 2015, when a single instance of the honey mushroom fungus (Armillaria ostoyoe) was found to extend underground across 2,385 acres in Oregon’s Malheur National Forest. The “humongous fungus,” as it’s affectionately called, has since yielded the title to an even more recently perceived organism. In 2022, biologists determined that an underwater stand of Australian seagrass (Posidonia australis) constituted one specimen, sprouted some 4,500 years ago from a single seed. It’s now grown to slightly over 49,000 acres, or 64 percent larger than the city of San Francisco. Unless humans hinder it as they did Pando, it should continue to thrive and grow.

Humans have also been compelled to perceive ourselves as more than merely Homo sapiens. When the genome of Homo neanderthalensis was sequenced in 2010, researchers were surprised to find Neanderthal genes present in a large amount of the current population. Recent samples estimate that the average person of primarily European ancestry is, genetically speaking, 1.7 percent Neanderthal; those of primarily Eastern Asian ancestry, 1.83 percent. Even more surprisingly, those of primarily African descent have been found to have a genome averaging 0.5 percent Neanderthal—a paradigm-upsetting discovery, as Neanderthals are believed to have emerged outside that continent. It indicates that instead of a diaspora of Homo sapiens spreading outward from Africa, a significant number of our ancestors returned there after intermingling with Homo neanderthalensis.

Another species, Homo denisova, has also contributed to our gene pool. Despite the fact that our only evidence of the species was discovered in Siberia and Tibet, aboriginal Australians carry 3 to 5 percent Denisovian DNA in their genome. Natives of Papua New Guinea carry 7 to 8 percent. We are, on the whole, not only a hybrid of species but the result of several vectors of migration. Our ancestry appears “almost as a spider web of interactions,” concludes Omer Gokumen, a geneticist at the University of Buffalo, “rather than a tree with distinct branches.”

Further complicating matters is the evolution of evolution itself. While Darwin’s theory of natural selection—biological change through random mutations—has been abundantly confirmed through genomic analysis, the same analysis has led to the surprising return of Lamarck’s theory of directed variation. While it appears to remain true that an organism does not change in direct response to its environment—a giraffe cannot will itself to have a longer neck—researchers in 2003 determined that although environmental factors do not change genes, they can change the expression of those genes, activating some and deactivating others. Furthermore, at least some of these expression patterns—now called epigenetics—appear capable of being passed on to subsequent generations, allowing Lamarck and Darwin to coexist after all.

In sum, life appears to exult in blurring the boundaries we place upon it. Buffon’s observation from two and a half centuries ago seems more relevant than ever.

This chain is not a simple thread which is only extended in length, it is a large web or rather a network, which, from interval to interval, casts branches to the side in order to unite with the networks of another order.

Not even Julian Huxley’s cladistics can meaningfully encapsulate all of life. While genome-sequencing technology gets faster and cheaper each year, it also produces cladistic connections that strain our ability to grasp at the larger whole. In classical taxonomy, birds presently remain in Linnaeus’s original class of Aves. In the separate Linnean class of Reptilia, alligators and crocodiles belong to the order Crocodylia, while lizards and snakes currently occupy the order Squamata. To a mindset based on morphology, this makes perfect sense: Crocodiles, lizards, and snakes resemble each other far more closely than any of them resemble birds. But cladistics traces monophyletic evolution—that is, descent from a common ancestor. Despite their appearance, Crocodylia are the closest living relatives of Aves, both having emerged from the cladistic group Pseudosuchia around a quarter of a billion years ago. An alligator is more closely related to a peacock than it is to a Komodo dragon. That Komodo dragon is more closely related to you.

Other surprises of cladistics: The lotus is less related to the water lily than it is to the sycamore tree. Roses and figs are closely related. The papaya’s nearest relative is that multiple-cultivar Brassica oleracea, known simultaneously as cabbage, broccoli, Brussels sprouts, cauliflower, and kale.

Some of the most disorienting results of cladistic taxonomy are underwater. The genus of Cancer, or crab, is now understood to be a broad collection of genetically distant species—in other words, not a genus at all. The advantages of developing a crablike anatomy are such that multiple monophyletic lines (organisms descending from a common ancestor) evolved into a convergent body shape, creating close resemblances in spite of vastly dissimilar origins. And while Linnaeus ultimately recast the class Pisces, or fish, to exclude whales and other cetaceans, so many evolutionary paths have adapted to free-swimming undersea life that Pisces has now been retired entirely. What we informally group as fish represent more than a dozen different monophyletic lines of descent, so genetically diverse that, as some biologists have enjoyed pointing out, “fish” do not really exist. If one drew a cladistic circle broad enough to encompass all fish, the circle would include humans as well.

Yet humans need “fish,” or something very like the concept of “fish,” to make sense of the world. Words are not just units of speech; they are units of thought. The decisions we make in organizing the world tend to disappear once we’ve made them, but they’re inevitably encoded in language.

Take colors, for instance. Among English-speaking people, we distinguish pink as a separate color from red. In the Malaysian language (Bahasa Malay), however, there is no pink. There is only merah, red. You can try to approximate a concept of pink by describing it as “light red,” but even then you’d be imprecise: The closest term in everyday use is merah muda, which means literally “young red,” and which can designate a bright red as well as a light one. You can convey the sense of pink by evoking a pink object, such as merah jambu, or “red like a guava.” The only problem is that you’re now describing not a range of shades but one shade in particular: the pink of a guava skin. Speaking Malaysian, of course, does not confer color-blindness, but to an Anglophone such vagueness can seem like an awkward and inaccurate approach to color. Why not just coin a word for “pink” and have done with it?

Yet English does exactly the same thing. We have no equivalent of pink for the blue portion of the spectrum. If you are not content with the vagueness of “light blue,” you have no choice but to get hyper-specific—“robin’s-egg blue,” for instance. In other words, there’s a chromatic gap in our language just as big as the one in Malaysian. But if you’re like most native English speakers, you’ve probably never noticed it. In contrast, Russian speakers learning English notice it right away: Their language divides up our “blue” into two colors, the paler goluboy and the darker siniy. What’s fascinating is that these distinctions are more than technicalities. They become hardwired into our brains. Neuroscientists have found that native Russian speakers are measurably faster than native English speakers at distinguishing dark-blue shades from lighter ones, presumably because, in their minds, the difference between goluboy and siniy is clear-cut.

As language-bound human beings, struggling to understand life’s complexities, we still require the semantic construct of agreed-upon labels. A team of biologists, Francine Pleijel and George Rouse, have proposed the LITU, or “least-inclusive taxonomic unit,” to replace the concept of species entirely. These would be provisional identities, which they describe as “statements about the current state of knowledge (or lack thereof)”—snapshots rather than static points, documented under the assumption that they might change as more genetic information becomes available. In other words, the LITU is remarkably similar to Buffon’s original concept of species—as an entity of reason rather than a physical fact. (It’s worth noting that Dr. Pleijel is a researcher at the contemporary Jardin des Plantes.)

This would move us away from lectotypes, allotypes, and other type specimens, a shift Pleijel and Rouse strongly advocate. According to them, “making taxonomists decide that a few dead specimens represent a species is an extravagant extrapolation that has no place in science.” Scientists are “forced by the existing codes of nomenclature to describe organisms as species when in fact they generally have no idea of what is going on in nature.”

At a conference in Mexico in the year 2000, the chemist Paul Crutzen proposed the declaration of a new geological epoch. Current standardized geology places us within the Holocene epoch, which succeeded the Pleistocene era approximately twelve thousand years ago. But Crutzen, awarded the Nobel Prize for his work analyzing Earth’s atmosphere, argued that humanity was wreaking profound change upon the planet, to the extent that it had ushered in an entirely new geological period. Owing to the “major and still growing impacts of human activities on earth and atmosphere,” he wrote in a joint statement delivered afterward, “it seems to us more than appropriate to emphasize the central role of mankind in geology and ecology by proposing to use the term ‘Anthropocene’ for the current geological epoch.”

Anthropocene means “the epoch of humans.” In 2009, Crutzen’s speech prompted the formation of the Anthropocene Working Group, an interdisciplinary task force charged with making recommendations for formal recognition of the epoch. In the course of their investigations, one member, the epistemologist and historian Jacques Grinevald, brought something to their attention: An “epoch of humans” had already been declared.

In The Epochs of Nature, the 1774 essay both included in Histoire Naturelle and published as a stand-alone volume, Buffon had argued that human-driven environmental change had proceeded to the point that it represented the “seventh and last epoch, when the power of man has assisted that of Nature.” This power, he concluded, was not universally positive. “The most despicable condition of the human species is not that of the savage,” he wrote,

but that of those nations that are a quarter policed, which have always been the real curse of human nature, and which civilized peoples still have trouble to contain today. They have, as we have said, ravaged the first happy land, they tore out the seeds of contentment…. Cast your eyes on the annals of all the peoples, you will count there twenty centuries of desolation for a few years of peace and repose.

Buffon did not anticipate modern global warming: Pollution on such a scale as to cause it was unimaginable in 1774. But he did believe that human habitation had already permanently changed the climate, and that the planet was not an inexhaustible resource. The rapid colonization and exploitation of other continents by European nations struck him as particularly troubling. “The English…did they not make a great mistake in extending too far the limits of their colonies?” he wrote. “The ancients seem to me to have had saner ideas about these matters; they planned emigrations only when their population became too great, and when their lands and their commerce no longer sufficed for their needs.”

Struck by the parallels, the Anthropocene Working Group commissioned an English translation of The Epochs of Nature and republished it anew. Why did a team of scientists, tasked with defining the present day, treat with urgency the words of a man who lived a quarter of a millennium ago? “It really is an extraordinary book,” they wrote in their introduction. “In some ways, the sciences have come full circle.”

It has become increasingly clear that one has to understand not just the parts (in minute detail) of the whole, but also the “whole” itself…. Among the most important incarnations of the whole is that of the Earth, the planet that we still entirely rely upon for our existence. Buffon’s vision of the Earth and—perhaps more particularly—the way he developed it, may have lessons for us yet.

This was just one of the more recent episodes in the ongoing rediscovery of Buffon, itself part of a burgeoning renaissance in complexist biology. In 1959, the anthropologist Loren Eisley commemorated the centennial of On the Origin of Species by acknowledging the debt Darwin owed to Buffon. Describing Buffon’s theory of species change as “nothing more than a rough sketch of evolution,” Eisley added that “Buffon managed, albeit in a somewhat scattered fashion, at least to mention every significant ingredient which was to be incorporated into Darwin’s great synthesis of 1859. [Italics in the original.] It is a great pity that his ideas were scattered and diffused throughout the vast body of his Natural History with its accounts of individual animals.” He continued,

Not only did this concealment make his interpretation difficult, but it lessened the impact of his evolutionary ideas…. However, almost everything necessary to originate a theory of natural selection existed in Buffon. It needed only to be brought together and removed from the protective ecclesiastical coloration which the exigencies of his time demanded.

Other reassessments followed. “Buffon asked almost all of the questions that science has since been striving to answer,” the historian Otis Fellows wrote in 1970.

Those who have looked with care, agree…that his glory lies in what he prepared for his successors: bold and seminal views on the common characters of life’s origin, laws of geographical distribution, a geological record of the earth’s evolution, extinction of old species, the successive appearance of new species, the unity of the human race.

In 1971, the botanist Frans Stafleu—one of Linnaeus’s most respected biographers—acknowledged the ways in which Buffon’s vision exceeded that of his rival. “Linnaeus mentions the law of generation which accounts for the production of identical unchanging forms, but that is as far as time goes,” Stafleu wrote.

In Buffon we encounter, however, a biologist of exceptional insight, almost free from traditional thought and religious scruples, a highly intelligent though somewhat speculative mind, exquisitely original and in many ways far ahead of his time…. The introduction of the historical element by Buffon was of the greatest importance for the evolution of biology as an independent science.

The Jardin des Plantes still thrives in Paris. It remains the mother campus of the National Museum of Natural History, whose fourteen locations are spread throughout France. The institution that Buffon finessed through the controversies of the Enlightenment, that Lamarck saved and Geoffroy defended during the French Revolution, is today both a respected research center and a public attraction, welcoming nearly two million visitors each year. The maps of Paris have been redrawn several times over the centuries, but the Jardin’s current address provides a fitting tribute to its history. It is now bounded on one edge by Rue Buffon, and Rue Cuvier on another. Its western boundary is a street that changes names. Up until Rue Cuvier, it is called Rue Linné. As it touches the Jardin, it becomes Rue Geoffroy Saint-Hilaire. This, appropriately, prevents the intersection of Rue Linné and Rue Buffon.

The heroic statue of Buffon remains. It now occupies a new place of honor, presiding over the Hall of Evolution, an exhibition displaying the growth and change of species through time—a parade through the shards of the broken lens of fixity, one of Buffon’s keystone achievements. Few of the visitors passing by know the statue is now a reliquary as well as a monument. The crystal urn containing his cerebellum, removed and measured after his death, was placed in the pedestal in 1870 (in Montbard his other remains, scattered during the revolution, were reassembled and reinterred in 1971).

The Gloriette, Buffon’s most personal monument, is intact and recently restored. If you climb up the winding path to its location on the summit of the Jardin’s only hill, you are rewarded with a view of well-tended greenery, the river Seine, and Paris beyond. Visible to your right are the museum’s research halls—the direct descendant of Buffon’s Cabinet du Roi—which contain only a small portion of the museum’s collection of more than sixty-two million specimens. The museum’s herbarium still contains specimens collected by Tournefort, Commerson, and Lamarck. It publishes a botanical journal named Adansonia, in honor of Michel Adanson.

In the middle distance, slightly to the left, lies the zoological garden that Geoffroy founded in 1793. His original grounds constitute just a small percentage of the four zoos the institution now operates. One of them is the Paris Zoological Park, four miles away in the Bois de Vincennes, where a strange and wonderful creature is on display. It is Physarum polycephalum, a bright-yellow but otherwise unremarkable-looking tree slime.

Physarum polycephalum defies the foundations of Linnean thought. It is an ordinary tree slime, common in European and North American forests, classified and labeled in 1822 but otherwise ignored until 1970, when a teaching assistant at Iowa State University discovered a surprising characteristic: The slime not only had an immune system but one that functioned externally rather than internally. A sample of polycephalum, taken from a rotting elm log, kept infections at bay by secreting an antiviral substance so potent that when sprayed upon crops it was 100 percent effective in eliminating tobacco mosaic, a potentially devastating virus that blighted not only tobacco plants but tomatoes, peppers, and cucumbers as well.

Over the course of the past five decades, more of the organism’s extraordinary aspects have come to light. As we’ve now discovered, it is neither an animal, a plant, nor a fungus. It can hibernate for years at a time. It has no musculature, yet it moves itself at a brisk 1.6 inches an hour. It is, somehow, a single-celled organism. (The Guinness Book of World Records proclaims it the largest cell on the planet.) If separated, segments are fully capable of operating independently, then reintegrating into the whole. They can even merge seamlessly into different specimens, gathered from different locations. Individual existence, it appears, is optional.

Its seeming simplicity belies an extraordinarily complicated sex life. Instead of two genders, male and female, Physarum polycephalum has 720 distinct forms of mating pairs, methods of inducing genetic variety that are the functional equivalent of genders. Sexuality and reproduction, as we’ve come to understand, accommodate a multitude of themes and variations.

Physarum polycephalum is also capable of learning. In order to most efficiently find food sources, it spreads itself out in a pattern both expanding and self-correcting, until it has covered the maximum amount of territory with the least amount of resources. By this measure, it can be seen as intelligent: The highly efficient networks it creates can find the quickest path out of a labyrinth or the shortest routes to connect multiple locations. In one experiment, it was presented with multiple food sources (in this case, oat flakes), placed in a pattern that replicated the geographic locations of Tokyo and thirty-six towns in the surrounding region. The slime mold reached out to all food sources with pathways that nearly replicated the Japanese rail system connecting those locations—a system carefully designed by humans to operate as efficiently as possible.

Despite its lack of a central nervous system, much less a brain, it’s also capable of remembering. Somehow, it manages to retain what it’s learned. If placed in the same labyrinth weeks apart, it will recognize the maze and re-create its previous escape route. Even a small piece of the original will do the same.

We don’t fully understand polycephalum’s intelligence, but that’s not keeping us from collaborating with it. In fact, we’ve recently recruited it to help us explore the cosmos. Current astrophysical theory holds that following the Big Bang, all matter in the universe dispersed in a pattern creating filaments between adjacent galaxies. Physical evidence of this dispersal is difficult to discover, since the filaments consist of thin, diffused streams of hydrogen gas. Astronomical instruments can detect these filaments, but only if pointed directly at them.

How to point the instruments in the right direction? By predicting in advance where these streams will be. To do that, astrophysicists have turned to polycephalum, harnessing the same efficiency it uses to solve mazes and re-create the Tokyo metropolitan train system. Using an artificial intelligence program designed to emulate the spore as closely as possible, they’ve been feeding it galactic maps and asking it to make connections. “A slime mold creates an optimized transport network, finding the most efficient pathways to connect food sources,” observes Dr. Joseph Burchett, the project’s chief researcher. “In the cosmic web, the growth of structure produces networks that are also, in a sense, optimal. The underlying processes are different, but they produce mathematical structures that are analogous.”

So far, the project has traced the connections between more than thirty-seven thousand galaxies. It’s just getting started, but it’s already demonstrated the power of shifting our perception of the living. Of approaching nature not as static objects to be inventoried, but as dynamic, interdependent manifestations of a greater whole.

To exist is to coexist. To be is to be in conversation.

In Buffon’s own words, “Nature is not a thing, for this thing would be everything.”

Nature is not a being, for that being would be God; but one can consider her an immense living power, which embraces everything, which animates everything…. Nature is herself a perpetually living finished product, a worker ceaselessly active, who knows how to employ everything, who in working by herself always on the same resources, far from exhausting them, renders them inexhaustible.