A Dutch anatomist and geologist, Eugene Dubois was known for his discovery of Pithecanthropus erectus. Born in the Netherlands in 1858, Dubois cultivated his naturalism with interest in the natural sciences. With support from his family, he studied medicine at Amsterdam University, whereby he received his doctorate in 1884. After graduating, Dubois was appointed as lecturer of anatomy in 1886. It is believed that his interest in evolution developed rapidly during this appointment. Perhaps believing that Asia was the cradle of human evolution, Dubois began to critically assess the possibilities of moving to the Dutch colony. The following year Dubois went to the Dutch East Indies (Indonesia) as a military surgeon. Although the island of Sumatra yielded few fossils, the move to the island of Java (Trinil) in 1890 would prove to be of great significance, ultimately yielding the fossil Pithecanthropus erectus (Java man) that would change both hominid taxonomy and secure Dubois’s place in the scientific community.
After careful examination of the fossil evidence, Dubois published his findings 4 years (1894) after his arrival in Java. In 1895, he returned to Europe to discuss and defend his interpretation of the fossil evidence. Although the scientific community was open to new evidence concerning evolution, most disagreed with his methodology and interpretations concerning the placement of this hominid form. During this time, Dubois became a professor of geology at the University of Amsterdam. Lecturing and traveling throughout Europe, he continued to defend his analysis of Java man. Unwavering in his interpretation, Dubois remained firm in his belief that Pithecanthropus erectus was an intermediate form between simian ancestry and humankind. The similarities of the morphological features of then recent discoveries in Java had increased the Java controversy. Regardless of his scientific demeanor and interpretation, physical anthropology benefited from Dubois’s quest for human ancestry.
Contributions and Perspectives
From 1891 to 1892, Dubois discovered a deposit of fossil bones at Trinil. In the strata that would date to the Pleistocene, the lapilli layer would yield a third molar (second molar found in October 1892), cranium, and a left femur. Besides the hominid evidence, other fossil remains of extinct creatures were recovered, among them being Stegodon, Bos elephas, rhinoceros, sus, felis, and hyena. Viewing the evidence as a whole, a picture of a bygone time emerged through the rock strata. Among the hominid fossil bones that were recovered, the interpretation of the thighbone and cranium led him to conclude that the specimen was an intermediate form between man and ape. Although he first referred to this new find as Anthropithecus erectus, he later renamed this hominid form as Pithecanthropus erectus.
Characteristically, Dubois (1896) assessed that the femur possessed both human and simian-like qualities. The differences between a human femur and that of Pithecanthropus erectus involved the following characteristics: increased rounded form of the inner side of the shaft, a round convex popliteal area, and more simian-like trochanteric line. Although the femur does have humanlike characteristics, Dubois asserted that the evidence must be evaluated in its entirety, including the other simian-like (perhaps a giant gibbon form) fossil bones that were discovered along with the femur. The calveria is measured at 185 mm (length) and 130 mm (breadth). According to Dubois, the skull is also simian in character. The cranial capacity is estimated at being around 1,000 cc, receding forehead, torus occipitals, and the pronouncement of the frontal bone’s orbital indicates a marked difference from human. Although similar to other anthropoid apes and some human characteristics (e.g., cranial capacity), Dubois continued to maintain that Pithecanthropus erectus was not a microcephalic idiot as some claimed, but a distinct and extinct hominid form between humankind and ape, an intermediate form that has Hylobatoid characteristics and is close to the genus Homo. The exact relationship and interpretation concerning the evidence was the center for agitated discussions, only to resurface with other hominid finds.
Discoveries of fossil hominids in both China (Peking man) and Java renewed interest in Dubois’s discovery and interpretation. According to the evaluations of then newly discovered evidence, the fossil remains appeared to be very similar to that of Pithecanthropus erectus. However, Dubois defended the independence of Pithecanthropus. Dubois claimed that the newly discovered fossil in Java was, in fact, Homo soloensis. Dubois stated that Homo soloensis is proto-Australian and that both Solo man and Rhodesian man are a primitive type of Homo sapiens, all of which are distinct from Homo neanderthalensis. Considering the cranial vault, low cranial capacity, pulp cavities of the teeth, and slender bones, the specimens of Homo soloensis and Homo rhodesiensi, and Sinanthropus are the most primitive type of Homo by which all human races can be derived. Any variation found among these types is due to cultural influences. In a reevaluation of Pithecanthropus in 1937, Dubois gave his reevaluation.
Dubois stated very clearly that Pithecanthropus, though not human, was a gigantic genus close to the gibbon. The morphological features of the calvaria are similar to anthropoid apes; however, the essential features of the femur indicates an erect position and gait. For these reasons, Dubois had given the name Pithecanthropus erectus. Furthermore, the lack of the parietal vertex and cranial capacity would be expected if a siamang gibbon had the body weight of Pithecanthropus (estimated using the dimensions of the femora). The increased cranial capacity, in Dubois’s opinion, was a product of progressive cerebration by great leaps (his italics), a law of phylogenic growth of the psychencephalon. Last, Dubois alluded to the conclusion that Pithecanthropus erectus may have undergone a transformation (his italics) toward human organization, whereby slight modifications of form could result in greater transformations. However, he still retained that this form was unique as well as extinct.
Despite Dubois’s academic and professional energies to maintain the distinctness of Pithecanthropus erectus, the expenditure was futile. Today, Pithecanthropus erectus is classified as Homo erectus, a hominid phase in human evolution that is 1.6 million years old. This phase in human evolution could be found in China, Indonesia, Java, Northwest Africa, Olduvai, and the Turkana Basin. Although there is still controversy concerning the defining characteristics, number of lineages, and rates of change, Homo erectus signifies a major segment in human evolution. It is unfortunate that Dubois, before his death in 1940, never accepted the diversity of Homo erectus that his specimen partly represented. Regardless of his known idiosyncrasies, Eugene Dubois had made important contributions in both discoveries and thought-provoking analysis to the understanding of human evolution.
References:
- Birx, H. J. (1988). Human evolution. Springfield, IL: Charles C Thomas.
- Dubois, E. (1896). On Pithecanthropus erectus: A transitional form between man and the apes. The Journal of the Anthropological Institute of Great Britain and Ireland, 25, 240-255.
- Dubois, E. (1937). On the fossil human skulls recently discovered in Java and Pithecanthropus Erectus. Man, 37, 1-7.
- Shipman, P. (2001). The man who found the missing link: Eugene Dubois and his lifelong quest to prove Darwin right. New York: Simon & Schuster.
