Many of us are introduced to the amoeba in science class at school but know very little about the amazing life of this versatile, shape-shifting cell. A Is for Amoeba is packed with surprising stories that give readers a richer appreciation of these astonishing microbes, revealing what amoebas have to tell us about the natural world and ourselves. Nicholas Money describes how amoebas are athletic predators with the rudiments of consciousness and how their sophisticated responses to injury help to explain the origins of pain and suffering in animals. Money explains how white blood cells and metastatic cancer cells in the human body behave like amoebas, curing and causing a range of illnesses, and discusses how research using artificial amoebas has profound implications for AI, robotics, and bioengineering. He also looks at the outsized role of amoebas in pop culture, from movies like The Blob to the cartoons of Gary Larson.
Why would a mycologist write a book about amoebas?
Nicholas P. Money: One of my goals as a mycologist is to demystify the mushrooms and molds and counter the impression that fungi are fundamentally different from the rest of life. Having said this, spore dispersal in the fungi involves some exceedingly complex movements, and we are still a long way from understanding how they grow. This framing of my research explains why I turned to amoebas a couple of years ago, thinking that their supposed simplicity would help me grapple with some of the most basic questions in biology about growth, reproduction, and evolution. But as I began to look more closely at amoebas it became apparent that their peculiarities are every bit as puzzling as those of the fungi and my biography of amoebas grew as this inquiry deepened. Amoebas are recognized by everyone from the simplest sketch of a wavy outline with a spot in the middle, but they are anything but the simpletons that they imagine.
How does the study of amoebas help us to understand ourselves?
NPM: I think they highlight the downside of having a brain. Amoebas show many expressions of awareness and agency when they move around obstacles, chase their prey, and evade their predators. The more we learn about amoebas, the smarter they seem. As their membranes flow and flinch we begin to see the evolutionary groundwork for all of our emotions, from delight to desperation and the rest of the monkey chatter between our ears. Experiments have even demonstrated the conditioned behaviors in amoebas that we thought were limited to animals with brains. This appreciation of sensitivity in single cells is quite disturbing. Amoebas are motivated by their inner state, responding to hunger for example, but we do not imagine that they have any capacity for self-reflection. An amoeba can react to internal signals that it is running out of energy but cannot think 鈥淚 am hungry.鈥� This mental sophistication requires a brain, which evolved in parallel with the experience of pain and suffering. Amoebas are blissfully ignorant, whereas animal life is a nightmare.
Amoeba is one thing and amoebas are many things. What is the strangest kind of amoeba?
NPM: The iconic cell that is in all the biology textbooks is Amoeba proteus, but there are thousands of other species of single-celled organisms that move in the same way. Fluid amoeboid movements are spread across the entire tree of life and there are some real surprises among these shape-changing organisms including vampire amoebas that turn red as they suck the juices from algae, amoebas that assemble beautiful shells using fragments of sand, and amoebas that hunt in packs to capture worms. Other oddities include giant marine amoebas that sit on the seafloor in the deepest parts of the oceans and look like cauliflowers. These are the organisms that I call sea scrunchies because they accumulate masses of gravel to form an exterior skeleton. They are among the largest single-celled organisms, but there is a lot that we don鈥檛 know about these creatures because they fall apart when we dredge them from the abyss.
There have been reports of lethal infections by amoebas. Where are these dangerous amoebas found?
NPM: Pathogenic or disease-causing amoebas are everywhere, in lakes and rivers, and can even thrive in drinking water that is not chlorinated. The worst infections are caused by a handful of amoeba species when they are snorted into the nasal cavities and crawl into the brain. Infections with these lethal brain-eating amoebas are very rare, although there is concern that they are becoming more widespread in response to climate change. People have also developed brain infections by using neti pots filled with water contaminated with amoebas for nasal irrigation. Rinsing contact lenses with tap water can also lead to a serious eye disease. All of these infections are very rare compared with the global curse of amoebic dysentery, which is transmitted in polluted drinking water and kills 55,000 people every year.
You say that human health and disease hinge on the activities of amoeboid cells in our bodies. What are these cells and how do they work in this opposing fashion?
NPM: The amoeboid way of moving, like honey spilling from a spoon, is reproduced in our protective immune cells and also in cancer cells when they spread between tissues. The hundreds of billions of amoeboid white blood cells in the body weigh about a kilogram and are responsible for gobbling bacteria throughout our lives. They also destroy billions of cells that would otherwise become cancerous every day. Intus me repent, ergo sum: they crawl inside me, therefore I am. Unfortunately, cells that become cancerous by evading the immune system also use an amoeboid form of movement to spread between tissues. Human amoebas good and bad are part and parcel of life and death.
Your book includes stories of some very strange people who have become obsessed with amoebas. Who were they?
NPM: The scientists who contributed to our understanding of amoebas are as peculiar as the microscopic universe that they explored. They include a suspected murderer, a criminal pedophile, and a German scientist who died after he deliberately infected himself with an amoeba to prove that it caused dysentery. Another bizarre amoebophile was Wilhelm Reich, the troubled inventor of the orgone accumulator or orgasmatron. Amoebas also attracted the attentions of Friedrich Nietzsche, who regarded self-consciousness as a property of all cells, and Sigmund Freud who likened the movements of amoebas to expressions of the human ego.
Nicholas P. Money is professor of biology at Miami University in Ohio and the author of many books, including Fungi and Human Life: The Molds, Mushrooms, and Medicines That Fill Our World, The Rise of Yeast: How the Sugar Fungus Shaped Civilization, and Mushrooms: A Natural and Cultural History. He lives in Oxford, Ohio. Website: