Out of Asia: A History of the Global Search for the Origins of Humankind
In the last two years, paleoanthropologists working in Africa and the Middle East have pushed back the origin of Homo sapiens by nearly 100,000 years and doubled the amount of time since our species began to migrate beyond the African continent (from 60,000 to 120,000 years ago). They have become “underground astronauts” to excavate rich deposits of previously unknown species, shared fossils with the world through downloadable, 3-D printed kits, and proposed new ways of engaging the public in scientific discovery. Less than six months ago, a research group at the University of Oxford and the Max Planck Institute published a paper arguing that modern humans were descended from not one but multiple ancestral human populations, scattered across the African continent and divided from one another by their different environments. African paleoanthropology is having a significant moment in the spotlight on the global stage.
The conventional narrative of the history of paleoanthropology runs something like this: in 1871, Charles Darwin, the father of evolution, proposed that Africa was the cradle of humankind in his book The Descent of Man. In 1925, Australian-born anatomist Raymond Dart discovered Australopithecus africanus, nicknamed the “Taung Baby,” in South Africa, but his work was crudely dismissed by snobbish metropolitan scientists elsewhere in the world. Fortunately, Dart persevered, and together with Louis and Mary Leakey in East Africa proved that Africa was where ancestral hominins and eventually Homo sapiens first evolved. Since the middle of the twentieth century, there has been explosive growth in the field marked by high-profile fossil discoveries, including Lucy (Australopithecus afarensis) and the 3.75 million-year-old Laetoli footprints, both found in the mid-1970s. Since the late 1990s, scientists in Ethiopia, Tanzania, South Africa, and increasingly North Africa and the Levant have made thrilling new fossil discoveries that have allowed us to build a more complete, if more complicated, picture of the deep history of human evolution.
However, this history has a few holes. We know that many evolutionists were very interested in the problem of human evolution immediately after Darwin published On the Origin of Species in 1859. The reference to Africa in Descent is extremely brief (less than two pages of discussion out of several hundred), but why did it take fifty years for someone like Dart to try to substantiate Darwin’s claim? It’s generally known that Dart’s Australopithecus was not taken seriously in the 1920s, but then what had changed by the mid-1950s, when Dart’s find was part of the body of proof for humanity’s African origins? If the answer wasn’t Africa, where did science and scientists believe the human species began instead? Out of Asia tells this story.
From approximately 1800 until 1950, most evolutionists—as well as anatomists, philologists, and other men of science—believed that the human species began in Asia (with the notable exception of Charles Darwin). Far from being an obscure or fringe theory, the Asian origins hypothesis was accepted by nearly all major evolutionists of the nineteenth century and served as the justification for the earliest major human ancestor fossil-hunting expeditions. In its most general form, the Asian origins hypothesis proposed that geological uplift and changing climates had forced proto-human apes to adapt to a new environment by descending from trees, standing upright, and developing tools, culture, and language. If language was the boundary between animals and humans, then identifying the beginning of language was the same as identifying the beginning of humanity. Therefore, the geographic locus of the earliest language would be the birthplace of the human species.
Since the 1950s, however, essentially all paleoanthropologists have agreed that Homo sapiens evolved on the African continent. Out of Asia explains how the “out of Asia” hypothesis came into being, and how the development of the “out of Africa” model could take place. In explaining this transition, I track the problem of human origins through diverse contexts, including nineteenth-century theories of race and language, twentieth-century expeditions for the “missing link” in Java and Mongolia, interwar geological surveys in Kenya and Tanzania, and the post-WWII quest to define a de-racialized, unified, and peaceful humanity. Using a combination of scientific and technical literature and archival material from more than twenty research sites in four countries, Out of Asia builds a nuanced, global portrait of the cultural and intellectual history of two scientific hypotheses and examines how these ideas have shaped the way we think about the deep history of humankind.