Zoobiquity Read online

  Still, among physicians, welcoming animal doctors as peers just “isn’t done.” As Darwin shrewdly observed, “we do not like to consider [animals] our equals.” And yet, all of biology, the foundation of medicine itself, relies on the fact that we are animals. Indeed, we share the vast majority of our genetic code with other creatures.

  And, of course, on some level we accept this vast biological overlap: almost every medicine we take—and prescribe—has been tested on animals. Indeed, if you asked most physicians what animals can teach us about human health, there is one place they would automatically point: the lab. But that is precisely not what I am talking about.

  This book isn’t about animal testing. Nor is it about the complex and important ethical issues of lab animal investigation. Instead, it introduces a new approach that could improve the health of both human and animal patients. This approach is based on a simple reality: animals in jungles, oceans, forests, and our homes sometimes get sick—just as we do. Veterinarians see and treat these illnesses among a wide variety of species. And yet physicians largely ignore this. That’s a major blind spot, because we could improve the health of all species by learning how animals live, die, get sick, and heal in their natural settings.

  As I started to focus on sameness, instead of being distracted by difference, it changed how I viewed my patients, their diseases, and even what it means to be a doctor. The line between “human” and “animal” started to blur. It was unsettling at first. Every echocardiogram I performed—on humans at UCLA and animals at the L.A. Zoo—suddenly exploded with familiarity and new meaning. Every mitral valve, every left ventricular apex, carried the echoes of our shared evolution and health challenges.

  The cardiologist in me was thrilled with this new perspective, the myriad overlaps. But as a psychiatrist, I wasn’t so sure. Physical similarities were one thing. Blood, bones, and beating hearts animate not just primates and other mammals but also birds, reptiles, and even fish. Still, I assumed, our uniquely developed human brains meant the similarities ended with our bodies. Certainly the overlap couldn’t extend to our minds and emotions. So I came at the question from a psychiatric perspective.

  Do animals get … obsessive-compulsive disorder (OCD)? Clinical depression? Substance addiction and abuse? Anxiety disorders? Do animals ever take their own lives? And again I sat back, a little astounded, while my research yielded a series of fascinating and surprising answers.

  Octopuses and stallions sometimes self-mutilate, in ways that echo the self-injuring patients we call “cutters.” Chimpanzees in the wild experience depression and sometimes die of it. The compulsions psychiatrists treat in their patients with OCD resemble behaviors veterinarians see in animal patients and call “stereotypies.”

  Suddenly, the benefits for human mental health seemed enormous. Perhaps a human patient compulsively burning himself with cigarettes could improve if his therapist talked shop with a bird specialist who had treated dozens of parrots with feather-picking disorder. Maybe Princess Diana or Angelina Jolie (who both publicly admitted cutting themselves with blades) could have found solace in discussing their urges with an equestrian expert who treats horses that compulsively bite themselves.

  Significantly for addicts and their therapists, species from birds to elephants are known to seek out psychotropic berries and plants for the presumed purpose of changing their sensory states—a.k.a. getting high. Bighorn sheep, water buffaloes, jaguars, and primates of many kinds consume—and then show the effects of—narcotics, hallucinogens, and other intoxicants. Naturalists have been noting these behaviors in the field for decades. Is a treatment—or at least a new perspective—for alcoholism or addiction lying dormant in all that animal research?

  I also searched for veterinary examples of depression and suicide. It seemed unlikely that animals would experience the same psychiatric urges to kill themselves that humans do. While the similar nature of their emotions has been persuasively described by behaviorists and veterinarians, I doubted that other animals share our foresight of death or knowledge of its power. Still I asked, “Do animals commit suicide?”

  Well, they don’t tie nooses around their necks or shoot themselves with revolvers, and they don’t leave notes explaining why they did it. But examples of what appears to be grief-related and life-threatening “self-neglect” (refusing food and water) crop up throughout the scientific literature and in accounts that veterinarians and pet owners tell. And insect suicide, driven by parasitic infection, has been well documented by entomologists.

  Which raises an interesting issue. Our physical body structures evolved over hundreds of millions of years. Perhaps modern human emotions too have evolved over millennia. Has natural selection played a role in what we feel, from anxiety, grief, and shame to pride, joy, and even schadenfreude?

  Although Darwin himself studied and wrote extensively about natural selection’s influence on human and animal emotions, none of my psychiatric training even touched on the possibility that human feelings could have evolutionary roots. In fact, it was almost the opposite. My education included stern warnings against the tantalizing pull to anthropomorphize. In those days, noticing pain or sadness on the face of an animal was criticized as projection, fantasy, or sloppy sentimentality. But scientific advancements of the past two decades suggest that we should adopt an updated perspective. Seeing too much of ourselves in other animals might not be the problem we think it is. Underappreciating our own animal natures may be the greater limitation.

  As a psychiatrist, I was officially convinced. Remaining ignorant of the mental and physical disorders of animals, I began to feel, was as narrow-minded as refusing to seek out important human research simply because it was reported in a foreign language.

  Still, the skeptic in me looked for any reason to explain away the similarities. Perhaps it was simply our shared environment. And after all, we humans have commandeered the food chain, imposing our dominant diets, weapons, and diseases on everything below us.

  So I began to look anew at conditions I’d long assumed to be uniquely human and modern. And with that I came across some remarkable findings: dinosaurs with gout, arthritis, stress fractures … even cancer. Not so long ago, paleontologists uncovered a mass in the fossilized skull of a Gorgosaurus, a close relative of Tyrannosaurus rex. A brain tumor, they said, had brought down one of the Earth’s most notorious carnivores, connecting a late-Mesozoic cancer patient to human brain cancer victims, including the composer George Gershwin, reggae artist Bob Marley, and U.S. Senator Ted Kennedy.

  Having spent a career taking care of human patients in the here and now, I was suddenly confronted by a shifted boundary. Cancer has struck and killed its victims for at least seventy million years. I wondered how this knowledge might redefine how patients and physicians view the disease … or even how oncologists might search for ways to cure it.

  Around this time I started working with Kathryn Bowers, a science journalist. A nondoctor with a background in social science and literature, she saw wider implications in these medical similarities. She urged me to view my overlapping experiences at the zoo and the hospital in a broader context. Together we began to research and write this book, bringing together medicine, evolution, anthropology, and zoology.

  We started with a survey of how philosophers and scientists through the centuries have positioned our species among our fellow creatures. Clearly, for as long as humans have been able to ponder it, we’ve been of two minds about the apparent fact that we are animals. Judging by the written record going back at least as far as Plato, our ancestors acknowledged the obvious similarities between us and the so-called lesser creatures. Plato mused, “Man is the plumeless genus of bipeds; birds are the plumed.” At the same time, people have long wanted to preserve a definition of humanity that kept us on a higher plane.

  With The Origin of Species, Charles Darwin gave us a new (and, to many, unnerving) way to conceive of ourselves in relation to animals—positing that man and beast exist as
different branches of the same tree rather than on different sides of a schism. Scholars of all stripes weighed in on whether and how humans were related to apes and other species.

  In the mid-twentieth century, this debate was reignited by The Naked Ape. With studied objectivity, Desmond Morris, a zoologist and former curator of mammals at the London Zoo, described human feeding, sleeping, fighting, and parenting the way a biologist would document animal behavior in the field.

  At about the time Morris was pointing out how similar we are to apes, two pioneering primatologists were documenting the many ways apes act like us. Jane Goodall was among the first to observe wild chimpanzees using tools and engaging in a type of organized warfare. For nearly twenty years, Dian Fossey lived near a group of gorillas in Rwanda, studying their vocalizations and social organization. Fossey’s and Goodall’s authoritative writings and memorable media appearances about the apes’ distinct personalities and extended family relationships fed a growing public interest in human-ape crossover even as the two women advanced serious scientific knowledge.

  Subsequently, many scholars attempted to demystify contemporary human life by studying animals and evolutionary biology. Two clashing powerhouses were the Harvard-based polymaths Edward O. Wilson and the late Stephen Jay Gould.

  Wilson rocked academia and the wider public discourse in 1975 with the publication of Sociobiology. Inspired by his extensive research on ants, Wilson connected social behavior in animals to evolutionary forces, including natural selection. When extended to human societies, this suggested that our genes outline many aspects of our nature and behavior. But Wilson’s theories were introduced in a particularly inhospitable climate. A mere three decades after eugenic theories were used to justify genocide, the world was not ready to hear that any aspects of human nature might be genetically predetermined. And as the civil rights and feminist movements were gearing up to dismantle centuries of racial, gender, and economic discrimination, public opinion would simply not tolerate theories with even a faint suggestion that “biology is destiny.” Furthermore, with the scientific revolutions of molecular biology and genome mapping a decade and a half in the future, Wilson didn’t yet have access to the high-tech tools that would ultimately back up many of his theories.

  Wilson was harshly branded by some of his academic colleagues as a racist, sexist “determinist.” One of his main detractors was Gould, a prominent paleontologist, geologist, and historian of science (who also happened to be one of my advisers on the undergraduate thesis I wrote about Darwin’s influence on public perceptions of physical deformity). In books such as The Panda’s Thumb, Gould argued that the subtleties of the human condition cannot be understood solely through natural selection. He cautioned readers that an overly genetic explanation of human behavior could reinforce regressive social agendas. His views matched the academic climate of the 1970s and ’80s—the same era in which New Historicists were reinterpreting literature and deconstructionists dismantling Western civilization courses.

  It was during this fertile period that Richard Dawkins published such provocative books as The Selfish Gene and The Blind Watchmaker. Dawkins characterized evolution as an unsentimental process, a self-interested and unceasing race among rival genes. Criticized, like Wilson, for having overstated the dominance of genetics over culture, Dawkins, an Oxford professor, nonetheless continues to probe the biological basis of human behavior, including its role in religion and belief in God. In a later work, The Ancestor’s Tale, Dawkins explored the concept of a unified biology, identifying the shared ancestry across species—among them hippos, jellyfish, and single-celled organisms.

  In 2005, Nature published a study that redefined the conversation: the human genome is 98.6 percent similar to that of chimpanzees. That single statistic inspired many people, and not only scientists, to reconsider what defines us as humans. Now, instead of trying to prove the existence of a connection between animals and humans, the race is on to explore the depth and breadth of this enormous overlap.

  The challenge has led scientists to explore far beyond great apes. Biologists are rapidly uncovering ancient genetic similarities that link diverse species—mammals, reptiles, birds, and even insects. The discovery is astonishing: nearly identical clusters of genes have been passed down for billions of years, from cell to cell and organism to organism. These remarkably unchanged gene groups code for similar structures and even similar reflexes across species. In other words, a common genetic “blueprint” instructed the embryos of Shamu, Secretariat, and Kate Middleton to grow different, yet homologous, limbs: steering flippers, thundering hooves, and regal, waving arms. Deep homology is the term coined by biologists Sean B. Carroll, Neil Shubin, and Cliff Tabin to describe these genetic kernels we share with nearly all creatures. Deep homology explains how genes taken from a sighted mouse and placed into a blind fruit fly cause the insect to grow structurally accurate fly eyes. And it is a deep homology that genetically connects keen, light-responsive vision in a hawk to photosensitivity in green algae. Deep homology traces our molecular lineage to our most ancient common ancestors. It proves that all living organisms, including plants, are long-lost relatives.

  Today, the specific nature/nurture controversy that so dominated the academic scene in the 1980s is something of a historical footnote. Advances in molecular biology, genetics, and neuroscience have shifted the debate away from whether there’s a genetic basis for behavior and toward a more nuanced conversation about how genes, culture, and environment interact. This has given rise to a burgeoning new field called “epigenetics.” Among other things, epigenetics considers how infection, toxins, food, other organisms, and even cultural practices can turn genes on and off to alter an animal’s development.

  Think about what that means. Evolution doesn’t just happen over huge numbers of generations or millions of years. It can happen to you or me, or any animal, within our own lifetimes. Amazingly, epigenetic changes to our DNA mean that the genes we pass on to our children can differ from the ones we inherited. Epigenetics and deep homology are two sides of the evolutionary coin. Epigenetics helps explain rapid evolutionary changes and highlights the role environments can play in genetic health. Deep homology reminds us of our ancient origins and the glacial pace at which much evolutionary change occurs.

  This stunning new perspective has started to change many fields, including biology, medicine, and psychology. When it was published in 2008, Your Inner Fish—Neil Shubin’s illuminating journey through our shared anatomy with ancient life forms—ignited excitement about the power of comparative biology to inspire new ideas in modern medicine. Shubin, a paleontologist and biologist at the University of Chicago, joins Randolph Nesse, George Williams, Peter Gluckman, and Stephen Stearns in advancing a new field of evolutionary medicine in their books Why We Get Sick, The Principles of Evolutionary Medicine, and Evolution in Health and Disease. Other influential scientists who’ve blazed trails through the shared terrain of human and animal biology include Sean B. Carroll (Endless Forms Most Beautiful), Jared Diamond (The Third Chimpanzee), Steven Pinker (The Blank Slate), Frans de Waal (Our Inner Ape), Robert Sapolsky (A Primate’s Memoir), and Jerry Coyne (Why Evolution Is True), to name just a few.

  Interest in the mental life of animals, dismissed for many years as too speculative and an exercise in anthropomorphizing, has gained greater acceptance, too. Books by Temple Grandin (Animals Make Us Human and Animals in Translation), Jeffrey Moussaieff Masson (When Elephants Weep), Marc Bekoff (The Emotional Lives of Animals), and Alexandra Horowitz (Inside of a Dog) have demonstrated animal cognition and behavior that resemble what we might call foresight, regret, shame, guilt, revenge, and love.

  Yet, while inspiring and illuminating, their books left me wanting a concrete way I could use their insights to improve my work as a physician. I wanted to break down the wall between physicians, veterinarians, and evolutionary biologists because together we are uniquely situated to explore the animal-human overlap where it matters most
urgently—in the effort to heal our patients.

  What had captivated me as a physician, what launched me on a journey that reshaped my entire approach to medicine, was a simple idea: to distill these decades of evolutionary research together with the collective wisdom of animal caregivers into a form both my patients and I could use within the four walls of my examining room.

  Kathryn and I had found, practically without exception, an animal correlate to every human disease we could think of—from “Jurassic cancer” to “diseases of civilization.” What we lacked was a name for this new fusion of veterinary, human, and evolutionary medicine.

  Finding nothing in the literature, we decided to come up with our own: “zoobiquity.” From the Greek for “animal,” zo, and the Latin for “everywhere,” ubique, “zoobiquity” joins two cultures (Greek and Latin), just as we are joining the “cultures” of human and animal medicine.

  Zoobiquity looks to animals, and the doctors who care for them, for answers to humankind’s pressing concerns. It peers back into our deep past—pausing but not stopping at great apes or even primates on the evolutionary timeline. It opens our minds to the common illnesses and shared vulnerabilities of the mammals, reptiles, birds, fish, insects, and even the bacteria with whom we evolved and share Earth.

  Engineers already seek inspiration from the natural world, a field called biomimetics. Wings and fins inspire designers to create vehicles that float and fly more efficiently. Cockroaches helped solve the pressing problem of how to keep a robot stable as it climbs over uneven terrain, after researchers copied the insect’s double-tripod legs and produced a machine that rarely tips over and can right itself when it does. Termites, mosquitoes, toucans, glowworms, and moths are just a few of the animals with superpower-like adaptations that scientists are trying to bring to a human market.