DUBOIS, MARIE EUGèNE FRANçOIS THOMAS

(b. Eijsden, Limburg, The Netherlands, 28 January 1858;

d. Haelen, Limburg, The Netherlands, 16 December 1940), paleoanthropology, comparative anatomy, paleontology, geology, hydrology.

Dubois earned worldwide fame through his discovery of Pithecanthropus erectus(“Java Man,” now Homo erectus) in the years 1891–1893. The remains of this hominid, which according to Dubois represented the “missing link” between apes and humans, were the first fossils ever to be accepted as convincing paleontological evidence for human evolution.

Career . Eugène Dubois was the oldest son of Jean Joseph Balthasar Dubois (1832–1893), a country apothecary and burgomaster of Eijsden, and Maria Catharina Floriberta Agnes Roebroeck (1830–1911). His parents were devout Catholics, and it testifies to the high value they set on a good education that they allowed their son to attend the Rijks Hogere Burgerschool (State High School), which was looked upon as a dangerously liberal institution by the Catholic clergy. In 1877, Dubois was registered at the University of Amsterdam as a student of medicine. Among his teachers were the botanist Hugo de Vries, the physiologist Thomas Place, and the anatomist Max Für-bringer, a pupil of Carl Gegenbaur. Dubois became an assistant to Fürbringer in 1881. In the same year, he was appointed as teacher of anatomy at both the State Training School for Art Teachers and the State School of Applied Art, filling both posts until 1887. Dubois qualified as a medical doctor in 1884, and he became lecturer in anatomy at Amsterdam University in 1886. In that year he married Anna Geertruida Lojenga (1862–1943) from Elburg. They were to have three children.

In 1887, Dubois gave up his career in Amsterdam and enlisted for eight years as a medical officer second class in the Royal Dutch East Indies Army with the express purpose of mounting a search for the missing link between humans and apes in the Dutch Indies (later Indonesia). He was first stationed on Sumatra and then transferred to Java, where he discovered the remains of Pithecanthropus erectus. After his return from the Indies in 1895, Dubois was awarded a honorary doctorate in botany and zoology in 1897 and became a professor of crystallography, mineralogy, geology, and paleontology at the University of Amsterdam in 1899. In 1907, physical geography was added to his teaching duties. From 1897 onwards, Dubois was also curator of Teylers Museum in Haarlem, the city where he and his family settled in the same year. He retired in 1929.

Search for the Missing Link . Dubois’s hunt for human ancestral remains in the Dutch East Indies was inspired by his conviction that only paleontological data could provide conclusive evidence for the descent of humans from a more apelike ancestor. The main protagonists of the German morphological approach to questions of descent, such as Dubois’s mentor Fürbringer, Gegenbaur and, particularly, Ernst Haeckel, felt that the reconstruction of phylogenies should primarily be based on comparative anatomical and embryological studies. Dubois was trained as a morpholo-gist and wrote several articles on the comparative anatomy of the larynx, yet he became dissatisfied with this approach and, having been an avid collector of fossils since his youth, turned his attention to paleontology.

Although he was seen as the most likely successor of Fürbringer after the latter’s intended return to Germany, Dubois, reading the works on human descent by Charles Darwin, Thomas Henry Huxley, and Ernst Haeckel, became so fascinated with the problem of human evolution that he decided to give up his academic career and travel to the Dutch East Indies as a medical officer in order to find an opportunity to search for the paleontological “missing link” between humans and apes. In the 1880s, there were as yet no known fossils that were accepted as evidence for human evolution. The nineteenth-century anthropological framework allowed for a broad range of variation of the human races, and fossil hominids, such as the Neanderthal remains discovered in 1856, were easily accommodated within this range. Dubois’s decision to try his luck in the Indies rather than in Africa (where Darwin had situated the cradle of humanity) was inspired by the discovery, in Pliocene deposits in the Indian Siwalik Hills in 1878, of a fossil ape that was believed to resemble humans more closely than any of the living anthropoid apes.

Furthermore, Dubois believed that not the African great apes, but the gibbons of Southeast Asia were the closest relatives of humans, since according to Darwin the upright posture had come first in the evolution of humans and the gibbons were able to walk upright—albeit only to a limited extent. In 1887, Dubois wrote an article about the prospects for paleontological and paleoanthropological research in the Indies that attracted the attention of the colonial government, not least because Dubois appealed to feelings of national prestige by pointing to the growing interest taken by foreign scientists in the paleontological exploration of the Indies. As a result, he obtained a grant from the colonial government to begin his search. Two sergeants of the Engineering Corps were assigned to his party, along with fifty forced laborers.

On Sumatra, Dubois discovered a fossil fauna that according to his estimate was too young to contain intermediate forms between humans and apes. On his request, he was transferred to Java, where a promising find of a fossil hominid skull had been made near Wadjak in 1888. After having installed his family in the village of Tulungagung on Central Java, Dubois soon found a second skull in the Wadjak caves, yet he had to conclude now that both skulls, though fossilized, did not represent intermediate forms but were human. He then made the important decision to redirect his work from the exploration of caves, the customary site for the search for hominid fossils, to the exploration of open territory. This decision proved crucial for the success of his campaign.

In 1891, after an exploration of several promising sites in the Kendeng Hills, Dubois began excavations in the banks of the river Solo near the hamlet of Trinil. An enormous number of vertebrate fossils, dated by Dubois to the late Pliocene or early Pleistocene age, were unearthed. Among them were a molar and a skullcap of a primate. Dubois initially ascribed these fossils to a new species of chimpanzee, Anthropopithecus, noting however that the cranium was more humanlike than that of any known anthropoid. A year later a well-preserved fossil thigh bone was found at the same site. Its characteristics were almost completely human, indicating that its owner must have walked upright. Dubois considered the three skeletal elements to belong to the same species and accordingly christened his fossil chimpanzee Anthropopithecus erectus. Yet further study convinced him that the remains represented exactly what he had been looking for: the missing link between apes and humans. He therefore decided that it was more appropriate to designate his find an ape-man, Pithecanthropus, instead of a man-ape, Anthropopithecus, being well aware that the name Pithecanthropus had been coined by Ernst Haeckel in 1868 for the hypothetical link between humans and apes. In 1894, Dubois published the results of his studies, under the title Pithecanthropus erectus: Eine menschenähnliche Uebergangsform aus Java (Pithecanthropus erectus: A humanlike transitional form from Java). In later publications he would add a jaw fragment, found in Kedung Brubus in the Kendeng Hills, and another molar, dug up in Trinil, to the remains of Pithecanthropus.

Dubois’s anatomical analysis of the Pithecanthropus fossils in his 1894 monograph bears clear witness of his training in the German morphological tradition in phylogenetic research, which had its roots in pre-Darwinian idealistic or typological morphology. Dubois compared the distinguishing features of the fossils with those of various apes and humans and on this basis characterized them as either “primitive” or “modern,” his unspoken assumption being that apes and humans represented distinct morphological types, each with its own typical features. In the early 2000s paleoanthropologists criticized this approach for failing to acknowledge the possibility of anatomical features having been shaped as adaptations to local circumstances. Such adaptations cannot unproblematically be taken to indicate phylogenetic affinities. It was mainly due to Dubois’s typological perspective that he became convinced that Pithecanthropus was a veritable ape-man, exhibiting an equal mix of ape-like and humanlike characteristics.

What Dubois envisaged Pithecanthropus to have looked like in the flesh can be gleaned from the life-size reconstruction that he sculpted with his own hands for the World Exhibition in Paris in 1900. As the reconstruction nicely illustrates, the fundamental idea underlying it was that Pithecanthropus stood halfway between apes and humans.

Reception of Pithecanthropus . After his return to Europe in 1895, Dubois spent several years endeavoring to convince the international scientific community of the importance of his discovery. He widely publicized his Pithecanthropus finds and displayed them at several international conferences and scientific meetings. Opinions on his discovery varied widely. Some critics did not accept Dubois’s contention that the fossils belonged together, ascribing the skull to an ape and the thighbone to a human. Others contested the transitional status of Pithecanthropus, claiming that it must have been a gibbon-like ape, while still others felt that the remains derived from a primitive human. Dubois did not fail to exploit this difference of opinion, arguing that it underscored the intermediate status of his find, given that he had established beyond reasonable doubt that the remains belonged together.

Dubois’s interpretation of Pithecanthropus as exactly intermediate between humans and apes was supported by authorities such as Haeckel, the German anatomist Gustav Schwalbe, and the American paleontologist Othniel C. Marsh, and a significant number of scientists accepted at least its evolutionary transitional status. Thus Dubois’s find was the first to be widely accepted as paleontological proof for human evolution, and in this sense his high hopes may be said to have been fulfilled. Furthermore, Dubois’s work served to initiate a debate, led by Schwalbe, that opened up the possibility of an evolutionary interpretation of the Neanderthal remains as an intermediate form between Pithecanthropus and modern humans.

Dubois, however, took a more somber view of the appreciation that his discovery met with. He soon became irritated by the opposition to his interpretation of the fossils. Matters became worse after 1900. In accordance with the then prevailing progressive view of evolution, Dubois had envisaged the development of humans as a simple linear process, from an anthropoid ape (possibly the primate found in the Siwalik Hills) to Pithecanthropus to modern humans. In the early twentieth century, however, when more and more fossil remains came to light, this view was exchanged for a branching model of human evolution with many dead ends. Support for this view came from the discovery, in 1912, of the supposedly early Pleistocene Piltdown remains, which showed a surprising combination of an apelike mandible and a fully human skull. (Only in 1953 would it become clear that “Piltdown Man” was a hoax and that the bones were forgeries.) The humanity of the Piltdown skull seemed to indicate that not the upright gait but enlargement of the capacity of the brain had come first in human evolution, a view that was elaborated in detail by the English anatomist Grafton Elliot Smith. This “brain first” hypothesis was reinforced by nationalistic and racist sentiments which favored an early origin of the genus Homo, since this allowed for a long period of separate development of the human races.

Since the Piltdown remains were taken to be only slightly (if at all) younger than the fossils of the much more apelike Pithecanthropus, the latter was removed from the line of human ancestry and relegated to a side branch. Dubois clung to his own view of Pithecanthropus as a missing link, but he no longer took part in the debates. He locked his fossils away and even his supporters were denied access to them. This behavior added in no small measure to the image of Dubois as an idiosyncratic and paranoid recluse. No doubt Dubois was a difficult man— the countless incidents that marked his career amply illustrate this—but his secretiveness was also motivated by his plan to publish an extensive and hopefully definitive monograph on his finds. As it turned out, however, he lacked the patience for such work. Likewise, he would publish very little on the collection of thousands of vertebrate fossils that he had unearthed in the Dutch Indies. He could only bring himself to write on them in 1907, when his priority in describing the new species in the collection was threatened by a paleontological expedition to Java led by Margarethe Selenka, wife of the zoologist Emil Selenka. It took international pressure, placed upon him via the Dutch Academy of Science in the 1920s, to make Dubois relieve the ban on investigation of the Pithecanthropus remains. Before doing so, he quickly churned out the most detailed description of the fossils he had ever written.

Pithecanthropus and Cephalization . After having withdrawn from the paleoanthropological scene, Dubois took up different interests and investigated a wide variety of geological problems. He explored the Teglian Clay, a geological formation that marks the boundary between the Pliocene and Pleistocene. He studied the climates of the geological past, having already in 1891 ventured the hypothesis that climatic changes were connected with the evolution of the Sun. Further he investigated the carbon cycle and produced an estimate of Earth’s age on the basis of his findings. He delved into the genesis of the Dutch sand dunes and linked their formation with that of the Strait of Dover. Finally he published on the origin of the Dutch peat bogs and contributed to the discussion on the drinking-water supply in the coastal provinces with studies on ground- and dune-water.

Still, Dubois did not turn his back on Pithecanthropus altogether. One of the new areas of research that he ventured into, the evolutionary development of cephalization in vertebrates, had attracted his interest because of its relevance to human evolution. With his cephalization studies, Dubois—and, in his footsteps, the French physiologist Louis Lapicque—undertook a pioneering attempt in the field of quantitative morphology, particularly of allometry (study of growth of one body part relative to growth of the rest). Dubois’s work aimed to show that there is a distinct mathematical relation between the development of an animal’s body (represented by its body weight) and the development of its central nervous system (represented by its brain weight), a relation that Dubois called its cephalization. He further argued that degrees of cephalization can be distinguished, according to the degree of evolutionary development of animals. These different degrees could also be expressed mathematically, as coefficients of cephalization, and animals that represented the same level of evolutionary development of the brain had the same cephalization coefficient. According to Dubois, the coefficients tallied nicely with the zoological system, with humans having the highest coefficient, followed by the apes, the ungulates, carnivores, rodents, insectivores, etc.

These results provided Dubois with additional support for his interpretation of Pithecanthropus erectus. For on the basis of an estimate of its brain weight (derived from the endocranial capacity of the skullcap) and its body weight (gauged from the measures of the thighbone) Dubois was able to calculate a coefficient of cephalization for Pithecanthropus that was indeed roughly half that of the human coefficient and double that of the great apes. Dubois was to continue his cephalization research in ever-greater detail in the 1910s and 1920s. He amassed a great amount of data, yet his interpretation of the results became more and more speculative. (Severe criticism of his work published in the 1930s and 1940s would throw the whole field into disrepute for several decades.)

Slowly but surely Dubois became convinced that cephalization in vertebrates had increased stepwise, brought about by a series of directed mutations that each entailed a doubling of the number of cells of the foremost part of the brain, dubbed the psychencephalon. Thus, Dubois argued in 1924, the psychencephalon of Pithecanthropus had had exactly twice the number of cells of that of apes and half that of humans, which again confirmed its intermediate position. This calculation required Dubois to assume a rather high body weight for Pithecanthropus of some 100 kilograms. Yet such a weight was plausible, he contended, provided it was assumed that Pithecanthropus had had rather apelike, particularly gibbonlike bodily proportions.

In 1935, Dubois published an article titled “On the Gibbon-Like Appearance of Pithecanthropus erectus.” Contemporaneous authors and later historians have claimed that this article indicated a sudden about-face in Dubois’s thinking, since he now seemed to reinterpret his fossils as deriving from an ape. Yet the article merely summarized the results of anatomical studies Dubois had undertaken to lend support to his assumption that Pithecanthropus had had a relatively high body weight, as required by his argument about its cephalization.

Viewed from this perspective, it is not difficult to understand why Dubois was unwilling to accept any relation between his Pithecanthropus and the new pithecanthropine finds made by the Canadian anatomist Davidson Black in China (described by him as Sinanthropus pekinensis) and by the German paleontologist Gustav Heinrich Ralph von Koenigswald on Java in the late 1920s and 1930s. From their study of these new fossils, Black, von Koenigswald, and the German anatomist Franz Weidenreich concluded that Pithecanthropus and Sinanthropus were much closer to Homo sapiens, a viewpoint that would later find expression in a new name for the species, Homo erectus. Dubois spent the last years of his life disputing this interpretation, arguing that the new finds derived from a primitive, yet fully human form, identical with the Wadjak remains he had found on Java. It was to no avail; Dubois lost all support for his by now highly labored and deviant interpretation.

In an obituary notice, Arthur Keith accurately characterized Dubois as an idealist who held to his ideas so firmly that his mind tended to bend facts rather than alter his ideas to fit them. To do justice to his life’s work, however, it should be added that it was exactly his imaginative mind and unbending faith in his convictions that made Dubois into the unorthodox and colorful pioneer of paleoanthropology that he was.

BIBLIOGRAPHY

The principal collection of archival material relating to Dubois’s life and work, containing diaries, correspondence, (field) notebooks, manuscripts, lecture notes, Dubois’s paleoanthropological and paleontological library, his reprint collection, drawings, photographs, etc., is kept in Naturalis, National Museum of Natural History, Leiden, The Netherlands, which also houses the thousands of fossils that Dubois excavated in the Indies, the Pithecanthropus remains included.

WORKS BY DUBOIS

“Zur Morphologie des Larynx.” Anatomische Anzeiger 1 (1886): 178–186, 225–231.

“Over de wenschelijkheid van een onderzoek naar de diluviale fauna van Ned. Indië, in het bijzonder van Sumatra.” Natuurkundig Tijdschrift voor Nederlandsch-Indië 48 (1889): 148–165.

Pithecanthropus erectus: Eine menschenähnliche Uebergangsform aus Java. Batavia: Landesdruckerei, 1894. Reprint: New York: Stechert, 1915.

The Climates of the Geological Past and Their Relation to the Evolution of the Sun. London: S. Sonnenschein, 1895.

“On Pithecanthropus erectus: A Transitional Form between Man and the Apes.” Scientific Transactions of the Royal Dublin Society, series 2, 6 (1896): 1–18.

“Ueber die Abhängigkeit des Hirngewichtes von der Körpergrösse bei den Säugethieren.” Archiv für Anthropologie25 (1898): 1–28.

“Eenige van Nederlandschen kant verkregen uitkomsten met betrekking tot de kennis der Kendeng-fauna (fauna van Trinil).” Tijdschrift van het Koninklijk Nederlandsch Aardrijkskundig Genootschap, series 2, 24 (1907): 449–458.

“Das geologische Alter der Kendeng- oder Trinil-Fauna.” Tijdschrift van het Koninklijk Nederlandsch Aardrijkskundig Genootschap, series 2, 25 (1908): 1235–1270.

“On the Relation between the Quantity of Brain and the Size of the Body in Vertebrates.” Proceedings of the Royal Dutch Academy of Science16 (1914): 647–668.

“Phylogenetic and Ontogenetic Increase of the Volume of the Brain in Vertebrates.” Proceedings of the Royal Dutch Academy of Science25 (1923): 230–255.

“On the Principal Characters of the Cranium and the Brain, the Mandible and the Teeth of Pithecanthropus erectus.” Proceedings of the Royal Dutch Academy of Science27 (1924): 265–278, 459–464.

“On the Principal Characters of the Femur of Pithecanthropus erectus.” Proceedings of the Royal Dutch Academy of Science29 (1926): 730–743.

“The Law of the Necessary Phylogenetic Perfection of the Psychencephalon.” Proceedings of the Royal Dutch Academy of Science31 (1928): 304–314.

“Die phylogenetische Grosshirnzunahme autonome Vervollkommnung der animalen Funktionen.” Biologia Generalis 6 (1930): 247–292.

“The Distinct Organization of Pithecanthropus of Which the Femur Bears Evidence, Now Confirmed from Other Individuals of the Described Species.” Proceedings of the Royal Dutch Academy of Science35 (1932): 716–722.

“On the Gibbon-Like Appearance of Pithecanthropus erectus.” Proceedings of the Royal Dutch Academy of Science38 (1935): 578–585.

“Racial Identity of Homo soloensis Oppenoort (Including Homo modjokertensis von Koenigswald) and Sinanthropus pekinensis Davidson Black.” Proceedings of the Royal Dutch Academy of Science39 (1936): 1180–1185.

“The Fossil Human Remains Discovered in Java by Dr. G. H. R. von Koenigswald and Attributed by Him to Pithecanthropus erectus, in Reality Remains of Homo wadjakensis (syn. Homo soloensis).” Proceedings of the Royal Dutch Academy of Science43 (1940): 494–496, 842–851, 1268–1275.

OTHER SOURCES

Bowler, Peter J. Theories of Human Evolution: A Century of Debate, 1844–1944. Baltimore. MD: Johns Hopkins University Press, 1986.

Brongersma, L. D. “De verzameling van Indische fossielen (Collectie Dubois).” De Indische Gids 63 (1941): 97–116.

Franzen, J. L. Auf den Spuren des Pithecanthropus: Leben und Werk von Prof. Dr. Gustav Heinrich Ralph von Koenigswald (1902–1982). Frankfurt am Main, Germany: Senckenberg Museum, 1984.

Hrdlika, Aleŝ. Skeletal Remains of Early Man. Smithsonian Miscellaneous Collections, vol. 83. Washington, DC: Smithsonian Institution, 1930. See pages 28–65.

Koenigswald, G. H. R. von. Begegnungen mit dem Vormenschen. Düsseldorf, Germany: Diederichs, 1955.

Reader, John. Missing Links: The Hunt for Earliest Man. London: Collins 1981.

Shipman, Pat. The Man Who Found the Missing Link: The Extraordinary Life of Eugène Dubois. London: Weidenfeld & Nicholson, 2001.

Spencer, Frank, ed. History of Physical Anthropology: An Encyclopedia, 2 vols. New York: Garland, 1997.

Theunissen, Bert. Eugène Dubois and the Ape-Man from Java: The History of the First Missing Link and Its Discoverer. London: Kluwer, 1988.

———, John de Vos, Paul Y. Sondaar, and Fachroel Aziz. “The Establishment of a Chronological Framework for the Hominid-Bearing Deposits of Java: A Historical Survey.” In Establishment of a Geologic Framework for Paleoanthropology, edited by Léo F. Laporte. Special paper 242. Boulder, CO: Geological Society of America, 1990.

Bert Theunissen