Java Man and Peking Man (Homo erectus)

Java Man is the popular name given to the fossil hominin discovered in 1891 by Eugene Dubois at the village of Trinil, on the banks of the Solo River in eastern Java. The find consisted of a skullcap and a femur. It is uncertain if are from the same individual and the femur is believed by some to be from a modern human. Dubois initially named his find Anthropithecus erectus (“Upright man-ape”, suggesting it was more ape-like than human) then he renamed it Pithecanthropus erectus (“Upright ape-man”, suggesting closer human affinities).

Peking Man is the popular name given to the fossil hominins discovered in the 1920s and 1930s at Zhoukoudian, near Beijing and described as Sinanthropus pekinensis by Davidson Black.

In 1944 both species were reclassified as Homo erectus by the late Ernst Mayr as part of a general tidying-up exercise of the bewildering plethora of hominin genera and species then recognised.

Eugene Dubois (1858-1940) was a Dutch anatomist who became fascinated with the subject of human origins. He had been an avid fossil-collector from childhood and believed that fossils provided the best way of elucidating evolutionary history, an approach which was not universally accepted at the time.

Dubois became convinced that the best place to search for the fossil origins of mankind would be the tropics, and to this end he joined the Dutch army as a doctor and had himself posted to the Dutch East Indies, arriving in Sumatra in December 1887. The demands of his day job meant it was quite a while before he could begin his search of the many caves in Sumatra, where he believed the fossil evidence would be found. Eventually, though, he was able to investigate the caves at Lida Adjer and duly began to unearth the bones of various mammals. Armed with this evidence, he managed to persuade the Dutch government to relieve him of his medical duties and allow him work full time on his fossil-hunting. He was also assigned the services of fifty convicts to help him with his excavations.

After failing to discover any human fossils in Sumatra, Dubois received permission in April 1890 to transfer his work to neighbouring Java. He began searching cave sites, but again without success, so he began investigating open sites as well. Finally he was rewarded with success and in October 1891, at Trinil, he recovered a low-domed angular thick-walled human skullcap with a large shelf-like brow ridge. In August 1892 he recovered a humanlike femur from what he believed to be the same site.

Convinced he had found the “missing link” – a transitional form between humans and apes, Dubois at first proposed the name Anthropithecus erectus based on what he believed were the ape-like proportions of its brain - which he estimated at 700cc - and the modernity of the femur. However in November 1892 he revised the cranial capacity upwards to 900cc, closer to that of a modern human than an ape. Accordingly he renamed the fossil Pithecanthropus erectus.

In 1895 Dubois returned to Europe and embarked on a tour to promote his claim to have found the missing link. Although the scientific community were intrigued by his discoveries, his conclusions were generally rejected. Disappointed, he eventually accepted a position as professor of geology at the University of Amsterdam and refused to allow any examination of his fossils until, under increasing pressure to grant access, he finally relented in 1923. His motives have been questioned: the popular view is that he was acting out of spite, like an angry schoolboy taking his ball and going home. However it is more likely that he was protecting his intellectual property. In 1897 he had permitted Gustav Schwalbe of the University of Strasburg to make a cast of the skullcap: Schwalbe had then produced a monograph that had been far more sympathetically received than any of Dubois’ own work.

By the 1920s and 1930s further hominin fossils were coming to light. In 1927 the Canadian anthropologist Davidson Black described Sinanthropus pekinensis (“Chinese man of Peking” [Beijing]), based on an examination of two teeth recovered from the cave site of Zhoukoudian in Dragon Bone Hill, near Beijing. The find became popularly known as Peking Man. Several skullcaps were recovered from the same site in subsequent years. Both Black and anatomist Franz Weidenreich noted similarities between the Zhoukoudian finds and Pithanthropus, but Dubois rejected the similarities.

Unfortunately the Zhoukoudian fossils were lost during World War II. Work at the site was halted by the Japanese invasion in 1937, but the fossils remained at the Cenozoic Research Laboratory of the Peking Union Medical College until 1941, when an attempt was made to transfer them to the United States for safekeeping. They were never seen again. It is thought that they were in possession of a group of US marines, who were captured when war broke out between Japan and the USA. Fortunately Weidenreich had made plaster casts, now in the American Museum of Natural History, New York. After the war, excavation resumed at Zhoukoudian and a number of discoveries have been made since, including two skull fragments. Zhoukoudian became a World Heritage site in 1987.

In 1936 palaeontologist Ralph von Koenigswald made a further discovery on Java itself. Excavating near Mojokerto, eastern Java, in 1936, von Koenigswald recovered a juvenile skull now known as the Mojokerto Child, who was anything from 2 to 6 years old at death, but again Dubois rejected any affinities to Pithecanthropus. The following year, von Koenigswald made further discoveries at Sangiran, East-Central Java with the aid of local people, who he promised to pay 10 cents for each find. The finds included fragments making up an almost-complete skull, though von Koenigswald’s delight at this discovery was somewhat tempered when he learned his helpers were breaking larger finds into smaller pieces to maximise their bounty!

Dubois argued his find was more ape-like than the later discoveries, leading to the popular misconception that he had repudiated his claim that it was an intermediate form. Eugene Dubois died in December 1940, having done himself few favours in the last four decades of his life. British anthropologist Sir Arthur Keith, writing in an obituary notice, observed that Dubois was “an idealist who held his ideas so firmly that he tended to bend the facts rather than alter his ideas to fit them.”

It is now generally accepted that the Javanese and Chinese hominins belong to the same or closely-related species, usually classed as Homo erectus. Some authorities recognise a separate species, Homo pekinensis, for the Chinese hominins.

Dating the Javanese fossils using modern argon-40/argon-39 and potassium/argon dating techniques of volcanic material recovered from the same context as the fossils has been problematic. This is due to deformation and distortion by earth movements of the stratigraphic beds with which the fossils are associated. Another problem has been uncertainty regarding the exact discovery sites, which were less scrupulously recorded than would now be the case. Dates ranging from as recent as 1.0 million to as long ago as 1.65 million have been proposed. Dates of 1.81 million years for the Mojokarto Child and 1.66 million years for the Sangiran fossil were reported in 1994 (Swisher et al, 1994).

Homo erectus (or pekinensis) fossils from Zhoukoudian and elsewhere in China have been dated to between 800,000 and 400,000 years old by palaeomagnetic and biostratigraphic techniques. However stone tools from the Nihewan Basin, 150km (90 miles) west of Beijing have been dated to as far back as 1.6 million years old, implying a much earlier arrival.

References:

Curtis G, Swisher C & Lewin R (2000): Java Man, Scribner, USA.

Klein R (1999): "The Human Career", 2nd edition, University of Chicago Press

Scarre C (2005) (Ed): “The human past”, Thames & Hudson.

CC Swisher 3rd, GH Curtis, T Jacob, AG Getty, A Suprijo and Widiasmoro (1994): Age of the earliest known hominids in Java, Indonesia, Science, Vol. 263, Issue 5150, 1118-1121, 25 February 1994.

© Christopher Seddon 2009