In 1887 a Dutch anatomist, Eugene Dubois, joined the Dutch army as a means to bring him to south Asia to hunt for the “missing link.” His major interest was the theory of evolution proposed by Charles Darwin in 1854. Dubois received an assignment in the Dutch East Indies (now Indonesia) where he assumed humans had evolved. He arrived first in Sumatra where he was able to obtain financial support from the army and began excavating in a number of caves. Initial results, however, proved disappointing, since the soil deposits were too young to yield evidence of the earliest humans.
Dubois heard news of some exciting new finds of extinct mammals in eastern Java and moved his research to the Solo river valley in East Java. The Dutch army supported his excavations by providing him with two engineers and fifty indigenous forced laborers. In 1891 Dubois’s workers found a skull cap (the majority of both parietals and the upper portion of the occipital bone) along the Solo River near the village of Trinil. A year later and approximately 50 feet from the skull cap, a femur (upper leg bone) was found. The find of the femur was proof to Dubois that what he had found was an “upright walking ape-man” which he named Pithecanthropus erectus, today known as Homo erectus. In 1894 Dubois published an article stating that Pithecanthropus erectus was a distant ancestor of modern man and had lived almost a million years ago. At the time authorities were of divided opinions; they regarded the find as either from a man, an ape, or an ape-man. The criticism from the scientific and religious communities caused Dubois to hide his discoveries under his house for 30 years.
In 1888 and 1890 two human skulls were recovered at Wadjak, about 65 miles from Trinil. Wadjak I was found by a Dutch mining engineer while prospecting for marble. Wadjak II was found by Dubois at the same site. The Wadjak skulls are modern Homo sapiens and less than 20,000 years old. These finds were reported only in the quarterly and annual reports to the Dutch East Indies government but not to the scientific community. Dubois withheld these specimens for fear that they would be associated with the Trinil finds. In 1920 Dubois publicly announced the skulls when another researcher claimed to have discovered the first proto-Australian.
In 1907-08 an expedition conducted by Selenka, another Dutch scientist, excavated 10,000 cubic meters down to 40 feet below the surface at the same location as the original Trinil site without finding any more remains of Homo erectus. The skeletal remains of hundreds of species of extinct animals were found and returned to the Netherlands.
In 1991, exactly one hundred years after Eugene Dubois’s workers discovered Homo erectus (Pithecanthropus erectus), a museum opened at the site of Trinil. The museum displays the bones of mammals found at Trinil, such as mammoth and an extinct form of bison. It also displays some of Dubois’s original documents and photographs, as well as replicas of the original skull, molar, and femur of Homo erectus.
The original fossil specimens of Dubois’s excavations can be found in the natural history museum at Leiden University in the Netherlands. One of Dubois’s most important contributions to understanding the natural history of Homo erectus is overlooked by most researchers: Dubois’s Indonesian workers collected and preserved hundreds of species of extinct animals and plants that can be studied at Leiden University.
- Larick, R., Ciochon, R. L., & Zaim., Y. (1999). Fossil farming in Java. Natural History, 108, 54-57.
- Lewin, R., & Foley, R. A. (2004). Principles of human evolution. Victoria, Australia: Blackwell.
- Shipman, P. (2001). The man who found the missing link. New York: Simon and Schuster.
- Swisher, C., Curtis, G. H., & Lewin, R. (2000). Java man: How two geologists’ dramatic discoveries changed our understanding of the evolutionary path to modern humans. New York: Scribner.
- Wolfpoff, M. H. (1999). Paleoanthropology. New York: McGraw-Hill.