Biology:Out of Asia theory

Short description: Scientific theory of human origins

The Out of Asia theory was a scientific theory that contended that modern humans first arose in Asia. Most anthropologists until the mid-20th century preferred Asia, over Africa, as the continent where the first hominids evolved. The recent African origin of modern humans ("Out of Africa") theory is better supported by available data.

History

Because of the rise of evolutionary thought in the late 19th century the out of Asia theory gained many new proponents, many of whom believed that the missing link would be found in Asia. Scientists such as Ernst Haeckel, Eugene Dubois, Henry Fairfield Osborn and Roy Chapman Andrews all thought Asia was where the major events of evolution had occurred.

Ernst Haeckel, the German evolutionary biologist, believed that Hindustan (South Asia) was the actual location where the first humans had evolved. Haeckel argued that humans were closely related to the primates of Southeast Asia and rejected Darwin's hypothesis of Africa.

Haeckel later claimed that the missing link was to be found on the lost continent of Lemuria located in the Indian Ocean. He believed that Lemuria was the home of the first humans, that Asia was the home of many of the earliest primates, and thus Asia was the cradle of hominin evolution. Haeckel also claimed that Lemuria connected Asia and Africa which allowed the migration of humans to the rest of the world.

Eugène Dubois, a Dutch paleoanthropologist and proponent of the out of Asia theory, discovered the skeletal remains of the first representative Homo erectus found in Java in 1891 on the banks of Solo River, East Java, Indonesia. The find later became known as Java man.

Replica of Homo erectus ("Peking man") skull from China.

Later, the discovery of Peking man persuaded anthropologists up until the 1930s that Asia was most likely the cradle of the human species. William Boyd Dawkins wrote that the tropical region of Asia was "the probable birthplace of the human race". The British anthropologist Alfred Cort Haddon wrote "There is reason to believe that mankind did not originate in Africa; but that all the main races in that continent reached it from Southern Asia".

Apart from Eugene Dubois, very few of the early human origin theorists actually visited Asia to see if their ideas were valid. This changed in the 1920s as a well-funded expedition was carried out in Asia called The Central Asiatic Expeditions. The expedition, led by Roy Chapman Andrews, visited parts of Central Asia including China and Mongolia to search for the origins of humankind.

Paleontologists who believed humans originated in Asia also include Johan Gunnar Andersson, Otto Zdansky and Walter W. Granger. All three of these scientists were known for visiting China and for their work and discoveries by excavating the sites at Zhoukoudian that yielded remains of so-called Peking man (Homo erectus pekinensis). Further funding for the excavations was carried out by Davidson Black a key proponent of the out of Asia theory. Because of the finds in Zhoukoudian, such as Peking Man, the focus of paleoanthropological research moved entirely to Asia, up until 1930.

The explorer Roy Chapman Andrews along with Henry Fairfield Osborn led several expeditions to North China and Mongolia from 1922 to 1928 known as the "Central Asiatic Expeditions" setting out to try to find the earliest human remains in Asia, however Andrews and his team found many other finds, such as dinosaur bones and fossil mammals and most notably the first known dinosaur nests full of eggs. Andrews' main account of these expeditions can be found in his book The New Conquest of Central Asia.

In Andrews' 1926 book On the Trail of the Ancient Man, Henry Fairfield Osborn noted in the preface that the birthplace of modern humans would be found in Asia and that he had predicted it decades earlier even before the Asiatic expeditions were carried out. Another key proponent of the out of Asia theory of this era was William Diller Matthew who also took part in the Central Asiatic expeditions; Matthew was well known for his deeply influential 1915 article "Climate and evolution". Matthew's theory was that climate change was how organisms came to live where we find them today in opposition to the theory of continental drift. His basic premise was that cyclical changes in global climate along with the prevailing tendency for mammals to disperse from north to south account for the odd geographic patterns of living mammals, he believed that humans and many other groups of modern mammals first evolved in the northern areas of the globe, especially central Asia because of the shifting climatic circumstances, Matthew firmly placed hominid origins in central Asia as he claimed that the high plateaux of Tibet was the forcing ground of mammalian evolution.

Later defenders of the out of Asia theory included Henry Fairfield Osborn, Davidson Black, and William King Gregory. Henry Fairfield Osborn was best known for his Dawn Man theory of human origins which he wrote would be found in Tibet and Mongolia. Osborn firmly believed that Asia had been the cradle of humankind. Davidson Black writing a paper in 1925 titled Asia and the dispersal of primates wrote that the origins of man were to be found in Tibet, British India, the Yung-Ling, and the Tarim Basin of China. His last paper published in 1934 before his death argued for human origins in an Eastern Asian context. William King Gregory also wrote that the Tarim Desert is the most likely place for human origins.

G. H. R. von Koenigswald, who found the first Gigantopithecus tooth in Hong Kong in 1935, continued to support the out of Asia theory.

Decline

The out of Asia theory later fell into decline, one of the reasons being that Franz Weidenreich merged the Asia hypothesis into the multiregional origin of modern humans, extending many other regions into his theory from the Old World with gene flow between various populations which influenced many anthropologists of the time.

The last support for the out of Asia theory was due to the finds of fossils such as the Dryopithecus and Ramapithecus in Eurasia up until the early 1980s. One of the last advocates of the out of Asia theory was Jia Lanpo who argued that the cradle of humanity had been in Southwest China, up until his death in 2001. Scholar Sigrid Schmalzer in her book The People's Peking man claims the only modern advocates of the out of Asia theory have their beliefs firmly rooted in Chinese Nationalism.