In Origin: A Genetic History of the Americas, Jennifer Raff deftly explains the methodology and thought process of a genetic archaeologist. Along the way, we also learn contemporary theories about the first arrival of Homo sapiens on this continent.This land clearly preceded us: the Americas existed as a landmass distinct from Eurasia for millions of years, during which time the populations of many species waxed and waned. Because the Americas formed by splitting from Pangea, this land was never empty. During the most recent hundred thousand years—coinciding with the rise of Homo sapiens in Africa and the dispersal of some small groups from our ancestral homeland—the Americas were home to a variety of macrofauna, including mastodons, mammoths, and giant sloths.After the arrival of Homo sapiens—who came via a Siberian landmass the approximate size of Texas (with its own local ecosystem!) and likely lived in that liminal region for generations—approximately half of all large animal species went extinct. We can’t know for certain that these extinctions were caused by humans and not climate change, but similar mass extinctions followed the spread of ancient humans onto every other continent, including Europe and Australia.Many stories have been told about humanity’s origin on this continent, each based on a mixture of evidence from traditional knowledge, linguistics, achaeology, and genetics, no two categories of which perfectly agree. Raff favors a theory that prioritizes genetic evidence, in which humans reached this continent almost 20,000 years ago then spread quickly across the new land, first by boat along the western shoreline and then gradually inland. Raff provides engrossing descriptions of the research that gave us evidence for this theory, such as an underwater archaeological dig replete with scuba gear and vacuum tubes. And though both your reviewers have used polymerase chain reactions to amplify DNA, it was never with the meticulous rigor necessary to detect ancient DNA within a world usually brimming with stray bits of ourselves. Raff’s work has required a lot of bleach!Crucially, Raff also conveys the emotional gravity inherent in conducting experiments that destroy small portions of sacred relics. For every aspect of her work, Raff has sought consent from the descendants of this continent’s first humans, a practice that was tragically rare among previous generations of researchers. We volleyed drafts of this review between a public high school and a county library, both built on land that was stewarded by the Miami, Delaware, Potawatomi, and Shawnee peoples. Although most people who lived here over the preceding millennia probably would not ascribe to the notion of ownership that underpins the U.S. government, this land was theirs. We are citizens of a nation that engaged in genocidal warfare against their nations. Our nation repeatedly signed and then violated binding contracts and treaties. Even while sitting in public buildings, it’s a lot to bear.If this topic interests you, we heartily recommend Raff’s book and suggest you pair it with The Dawn of Everything by David Graeber and David Wengrow, which provides an admittedly speculative depiction of what the political systems of this continent’s first inhabitants may have been like. Graeber and Wengrow argue that there was a diversity of complex, integrated, intentional governances among the First Peoples, many of which were likely more equitable than our own.It can be daunting to look out the window and imagine all the lives this land has seen. Raff helps us understand the evidence by which we’ve gradually progressed from imagining to knowing. Among younger readers, perhaps she’ll spark the urge to join her hunt.
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Open Access
Mar 6, 2024
Alessandra Vezzoli + 5
