In “Biography of Resistance,” Zaman considers antibiotics as the major weapon for killing bacterial pathogens — and the ways in which this war has backfired. Bacteria and fungi have been producing antibiotics for many hundreds of millions of years. Relatively recently, humans figured out that they could co-opt some of these to control pathogenic bacteria. Doing so saved millions of lives. But it also increased the commonness of resistant bacteria, that is, bacteria that are impervious to antibiotics and, as a result, difficult to kill. “Biography of Resistance” profiles these bacteria, but also the people who study them. It is a useful, engaging opus. There are now resistant strains of the bacteria that cause tuberculosis and other disease, but also resistant malaria protists, bedbugs, head lice, crop pests and even garden weeds. Zaman tells the stories of researchers working to understand the evolution, and to a lesser extent ecology, of bacterial resistance and when and why it emerges. Resistance is ancient (resistant bacteria can be found deep in caves beyond the reach of human influence), but it has taken on new forms and dynamics in light of the ways in which we have wielded antibiotics. Zaman’s book includes histories of key moments in microbiology, reminders of how fast our perspectives on the microscopic world have evolved. When Anton van Leeuwenhoek first discovered microbial life in the 1600s, he imagined it to be wondrous and mostly beneficial. Once Louis Pasteur discovered that microbes could both make us sick and make beer, he came to see some species as dangerous but others as beneficial. Then once we developed antibiotics, scientists began to talk more often about a “war on germs,” in which germs were understood to be faceless, dangerous creatures all around us. With these increasingly resistant strains, the germs now seem to be taking this war seriously.