This is another one of those books that must be read. And even after 38 years, there’s a lot of good stuff in it. The thesis is summed up in the title, which has entered the language as a short-hand descriptor for the idea that “the most important changes brought about by the Columbian voyages were biological in nature,” even if not all the people who use the term agree with Crosby that the interaction of the old world and the new “has left us with not a richer but a more impoverished genetic pool.” (xiv, 219) Crosby’s narrative sets the scene by comparing the old world and the new, to show the biological contrasts between them. He traces European conquest, and the diseases that spread with (and sometimes ahead of) conquistadors and settlers. Crosby then describes the (mostly plant) species that were brought from the Americas to the old world, and the (mostly animal) species the Spanish brought to the new (interestingly, he says most of the really significant species were introduced by the Spanish by 1500, long before North American settlement was begun. 108). After devoting a full chapter to the controversy over the origin of syphilis, Crosby concludes with a look at how American food crops enabled population growth in both Europe and Asia (and continue to, to the present day). Some of the interesting items along the way include Crosby’s brief discussion of the possible influence of the new world on tradition and religious authority in the old. “Christian and Aristotelian” belief systems, he says, “proved too cramped to accomodate the New World...men of the Columbian generation discovered that ‘Ptolomeus, and others knewe not the halfe.’” (9) Crosby says an argument about “multiple creations” was carried on in Europe until 1859, when Darwin finally laid it to rest, “while also knocking loose a large part of the foundation of traditional Judaism and Christianity.” (14) Crosby’s discussion of the extinction event that wiped out American megafauna has probably been eclipsed by more recent scientific findings, just as his discussion of the worldwide distribution of blood-types has been overtaken by DNA analysis, but in their day they were great examples of interdisciplinary thinking. Many of the details Crosby includes are startling. Cotton Mather’s description of the 1616-17 epidemic that wiped out most of the Massachusetts Indians as a Providential clearing of the woods “of those pernicious creatures, to make room for better growth,” confirms my impression of the Puritan leader. (41) The idea that “a million Indians lived on Santo Domingo when the Europeans arrived,” and that they were reduced by 1548 to 500, is something you really have to sit with for a while and think about. (45) The “population of central Mexican dropped from about 25 million on the eve of conquest to 16.8 million a decade later.” (53) That doesn’t seem as bad, until it sinks in that it means one out of every three people was dead, in just ten years. Makes all the recent movies about plagues and human apocalypse seem like so many nightmares of a guilty white American conscience.I didn’t know that when Columbus returned, he brought “seventeen ships, 1,200 men, and seeds and cuttings for the planting of wheat, chickpeas, melons, onions, radishes, salad greens, grape vines, sugar cane, and fruit stones for the founding of orchards.” (67) And it never occurred to me that some new world species, like the white potato, found their way to places like New England via Europe (brought “by the Scotch-Irish...in 1718.” 66) Other interesting details: “the banana, brought from the Canaries in 1516.” (68) “Cattle...first brought to Mexico for breeding purposes in 1521.” (87) But by 1614, “the residents of Santiago [Chile] possessed 39,250 head,” (91) as well as 623,825 sheep. (94) I also didn’t know, but should have guessed after reading about De Soto’s expedition through Florida, that when Pizarro crossed the Andes into Peru in 1540, he brought over 2,000 pigs with him. (79) Somebody should write a history of the conquest that focuses on what it must have been like, moving conquistadors and their pigs through the wild Americas.