Plagues upon the Earth: Disease and the Course of Human History by Kyle Harper

Abstract

Reviewed by: Plagues upon the Earth: Disease and the Course of Human History by Kyle Harper Brandon T. McDonald Plagues upon the Earth: Disease and the Course of Human History Kyle Harper Princeton, NJ: Princeton University Press, 2021. Pp. x + 686. ISBN: 9780691192123 Presses are encouraged to submit books dealing with Late Antiquity for consideration for review to any of JLA's three Book Review Editors: Maria Doerfler (maria.doerfler@yale.edu); John Weisweiler (j.weisweiler@lmu.de); and Damián Fernández (dfernandez@niu.edu). We are inseparable from pathogens (at least, for much of our history). With good reason, this theme reverberates through the chapters of Kyle Harper's recent book, Plagues upon the Earth, a global history of disease stretching back to before our emergence as a species. We will call it a work of historical epidemiology. An ancient economic historian, Harper follows up his previous monograph, The Fate of Rome: Climate, Disease, and the End of an Empire (Princeton, 2017)—a considerable portion of which dealt with infectious disease—by expanding from Roman epidemiological events to a full history of humans' experience with pathogens. He delivers this history—a massive undertaking at nearly 700 pages—with a strong grasp of the science (particularly microbiology and phylogenetics) and an adeptness at making it accessible that is rarely reached in historical scholarship. A struggle to contend with the challenges in writing a global history of disease is somewhat apparent, given that our evidence (whether it be demographic or genomic) is unsurprisingly biased towards Europe. Harper, keenly aware of the difficulties, accepts them and provides as close to an aerial perspective of the human world's exposure to pathogens as possible, with caveats and without firmly extrapolating "Western" evidence. Plagues upon the Earth has four parts, each taking on a crucial aspect of our evolving relationship with germs, and these parts are divided into three chapters. Part One, "Fire," gives the reader an overview of the microbes that have afflicted Homo sapiens and our predecessors for hundreds to thousands of millennia. Harper familiarizes us with humans' most deadly and notorious disease culprits, such as species of bacteria and viruses, as well as less villainized microbes like protozoa and helminths, elucidating that those infecting early chimpanzees (our closest living ape relative) and Homo erectus (an ancestor of modern humans) in some cases evolved to adapt to us. He explains how our understanding of the emergence and evolution of pathogens has improved immensely with the advance of paleogenomics (ancient DNA analysis) and phylogenetics (the study of evolutionary development and the diversification of species), which he labels and continually refers to as "time travel" and "tree thinking," respectively—terms that are a bit playful but nonetheless descriptively effective for reaching a wider audience. These scientific methods, Harper rightly argues, afford us better comprehension of the germs that affected our ancestors and today allow us to write a better-informed history of disease. Early [End Page 238] on, the reader realizes that the improvements in science are a partial basis behind Plagues upon the Earth; perhaps a successor, or an enlightened reply, to works like William McNeil's Plagues and Peoples (Harmondsworth, 1976) or Jared Diamond's Gun, Germs, and Steel (New York, 1997), both of which are cited and referenced in the text multiple times. Ultimately, Part One serves to illustrate not only the ubiquity of microbes, both harmful and not, but also that they were already an age-old fixture on this planet long before Homo sapiens arose. Part Two, "Farms," delves into the diverse ecological settings our ancestors explored and settled into, as well as the significance of these migrations to pathogenic adaptation. Harper begins Part Two with an intriguing story about William Black, an eighteenth-century London doctor who embarked on the huge research task of attempting to understand the main reasons humans die (A Comparative View of the Mortality of the Human Species at All Ages; and the Diseases and Casualties by which They Are Destroyed or Annoyed, London, 1788). These anecdotes are sprinkled throughout the book, usually at the beginning of sections. In the Fate of Rome, Harper strayed from his place as a strictly...