When Jared Diamond’s Pulitzer Prize-winning Guns, Germs, and Steel appeared in 1997, it changed the course of how history was written. It was no longer just the stage for kings and conquerors, or even social and economic advancement. Anthropology, evolutionary biology, genetics, linguistics and ecology also had a say.
Among Diamond’s insights into how changes in food production and the domestication of animals influenced social and political organisation was the impact of infectious diseases. Although more recent research has challenged his assumptions, some elaborated in the subsequent Collapse, the emphasis on wider considerations has increased.
Peter Frankopan’s The Earth Transformed – reviewed in these pages in March – reinterpreted the arc of human history through the lens of environmental and climatic change. An anthropologist and an archaeologist did the same in The Dawn of Everything, while historian Yuval Noah Harari’s Sapiens remains the gold standard for many readers.
These doorstopper books are not quick reading, due to the amount of knowledge they contain. But Jeremy Kennedy, a lecturer in global public health at Queen Mary University in London and a neophyte in this publishing field, lightens the task.
He entices the reader into each of his eight “plague” chapters with analogies from modern culture, from Lord of the Rings and The Seventh Seal to Monty Python’s Life of Brian. He reckons Diamond understated the role of germs, given all life started as a single-celled bacterium that contained both DNA for genetic information and an energy molecule called ATP. These existed soon after Earth’s beginnings 4.6 billion years ago.
“Bacteria made the planet habitable for complex life,” Kennedy states. As the planet cooled, oxygen combined with methane to form carbon dioxide. Bacteria converted carbon, nitrogen, sulphur and phosphorus into nutrients.
The first humans did not evolve from those life forms until 300,000 years ago. But it was not until the 17th century that Dutch scientist Antonie van Leeuwenhoek, reversing the lens of a telescope, discovered microbes in the human body that hitherto were invisible to the human eye.
Until then, unscientific explanations were the norm for microbial diseases that had been the scourge of most human societies. The ancient Greeks and Romans blamed the gods, as did indigenous cultures.
But these pathogens attributed to divine retribution didn’t affect everyone the same. Early farmers initially had more diseases than the hunter-gatherers before building up immunity. “The adoption of settled agriculture, coupled with population growth and increased trade, created a golden age for viruses, microbes and other animals.”
Many of today’s diseases, including hepatitis B, measles and TB, date back to the Neolithic period of 7000 years ago. Indigenous populations had more to fear from foreigners with immunity to deadly diseases than from land grabs.
The dark-skinned people who apparently built Stonehenge were replaced by fair-skinned migrants from the eastern European steppes. They had brought the pneumonic Neolithic Black Plague, spread by coughing and sneezing rather than by fleas on rats which made its later variants so destructive.
Population losses from these plagues were severe, and were more frequent during periods of warmer climates, which increased food production and encouraged the growth of cities. These plagues continued until the 18th century in Europe, held back only using quarantines or cordons sanitaires.
While the Christian churches benefited from these deaths through property inheritance, the labour shortages also led to increased invention of labour-saving devices. One of these was the printing press, which fuelled the Reformation and the rise of capitalism.
It took another 200 years after Antonie van Leeuwenhoek’s discoveries for Louis Pasteur to establish that “animalcules” were the cause of fermentation, souring, putrefaction and many diseases, leading to the development of vaccines.
The deadliest weapons the more immune European explorers and settlers wielded on indigenous cultures in the Americas, Africa and the Pacific were smallpox, salmonella, measles and influenza rather than swords, muskets and cannon. But it wasn’t a one-way street. African viruses prevented widespread European settlement, while the New World of the Americas was rife with syphilis that was exported back to Europe. The increased scepticism towards vaccination, resulting in a resurgence of polio and other viruses, is another unwelcome development in microbial history.
Pathogenesis: How Germs Made History, by Jonathan Kennedy (Torva, $40).
