Eugene Dubois was the first person to ever deliberately search for fossils of human ancestors. Only a handful of fossil humans had already been discovered, and those were by chance. In a remarkable story of dedication and luck, Dubois succeeded in his unlikely quest.
Eugene Dubois was born in the town of Eijsden in the Netherlands in 1858. As a boy he was fascinated by natural history, a pursuit encouraged by his pharmacist father. An excellent student, he studied medicine and graduated as a doctor in 1884. Two years later he was appointed an anatomy lecturer at Amsterdam University, and married in the same year. The following year, he gave it up to go to the Dutch East Indies, now Indonesia, to look for fossils of human ancestors.
No one is quite sure why Dubois threw up a good job to travel half way around the world on what most people would surely have considered a wild goose chase. Obviously, he must have been interested in human evolution. He had also discovered that he disliked his job as an anatomy lecturer, especially his teaching duties. Finally, Dubois apparently felt that his advisor, Max Furbringer, had claimed credit for some of Dubois' own ideas, and Dubois wanted to end their professional relationship. There was little or no merit to this; Furbringer seems to have always behaved correctly and even generously to Dubois. But throughout his life, Dubois seems to have had an almost fanatical fear of other scientists taking credit for his ideas.
He chose the East Indies because, like Darwin and many others, he felt that humans had evolved in the tropics. He believed that humans were closely related to gibbons, which are found in Indonesia. A fossil ape that had been found in India also encouraged him to believe that Asia would be a good place to look for hominid fossils. And, as a Dutchman, a Dutch colony like Indonesia was a convenient place for him to live and work.
Dubois joined the Dutch Army as a medical officer, and he and his wife and baby arrived at the island of Sumatra in December 1887. When he had spare time from his medical duties, he searched for fossils. Early results were promising, and the government assigned him two engineers and 50 forced labourers to help him, but the results were disappointing due to the difficult conditions. The region was densely forested without paths, water was short, one of the engineers was transferred because he was useless and the other one died, and many of his labourers ran away or were sick. Some fossils were found, but they were of fairly recent date.
Dubois decided prospects would be better in Java, and got himself transferred there in 1890. One reason for going there had been a human skull which a mining engineer had found at Wadjak in 1888. Dubois started searching in the same place, and found a second less complete skull. Following this, he started searching in more open areas, especially a site on the banks of the Solo River which proved productive. Once again, he had been assigned two engineers and a crew of convict labourers to help him. (This time the engineers were both competent and managed to stay alive.)
In September 1890, his workers found a human, or human-like, fossil at Koedoeng Broeboes. This consisted of the right side of the chin of a lower jaw and three attached teeth. In August 1891 he found a primate molar tooth. Two months later and one meter away was found an intact skullcap, the fossil which would be known as Java Man. In August 1892, a third primate fossil, an almost complete left thigh bone, was found between 10 and 15 meters away from the skullcap.
In 1894 Dubois published a description of his fossils, naming them Pithecanthropus erectus, describing it as neither ape nor human, but something intermediate. In 1895 he returned to Europe to promote the fossil and his interpretation. A few scientists enthusiastically endorsed Dubois' work, but most disagreed with his interpretation. Almost everyone agreed that the femur was effectively indistinguishable from a human femur, but it was widely doubted whether it had, as Dubois claimed, come from the same individual as the skullcap. Some French scientists cautiously accepted that Dubois might be right. German scientists tended to the view that the skullcap was that of a giant ape such as a gibbon, while English scientists tended to view it as a human, coming from either a primitive or a pathological individual, but there were plenty of other opinions. Many scientists pointed out similarities between the Java Man skullcap and Neandertal fossils.
Dubois vigorously defended his interpretation, responding to his critics, providing further information on the fossils, and travelling around western Europe to speak and display the fossils. He pointed out that while many experts considered the skull ape-like and many considered it human-like, this actually strengthened his argument that it was a mixture of both. As time went on, Dubois' position gained more support, although the fossils remained controversial.
Around 1900 Dubois ceased to discuss Java Man, and hid the fossils in his home while he moved on to other research topics. This may have been to protect his intellectual priority; Dubois had been furious when another scholar had obtained a cast of the skullcap and then proceeded to produce a detailed study which surpassed anything Dubois had done. With Dubois out of the argument and the fossils inaccessible, the controversy died down. In 1897 he was awarded an honorary doctorate in botany and zoology by the University of Amsterdam, and in 1899 became a professor there in crystallography, mineralogy, geology and paleontology. (This was not as impressive as it sounded; he was earning less than he had 10 years earlier as an anatomy lecturer).
Over the next few decades he performed research in a number of areas. In particular, he devoted much effort to understanding the relationship between body weight and brain weight. He eventually came up with a complicated scheme in which all animals had a certain degree of encephalization, which increased in jumps of two (so humans were 1, apes were 1/4, cats and dogs were 1/8, etc.). It was a pioneering approach, but Dubois' results were hopelessly flawed, based on a small amount of real data and a large amount of speculation and special pleading. Under this scheme, Java Man, especially if reconstructed with gibbon-like body proportions, had an index of 1/2, which placed it nicely in the gap between apes and humans. (Gould 1993)
It was not until 1923 that Dubois, under pressure from scientists, once again allowed access to the Java Man fossils. That and the discovery of similar fossils caused it to once again become a topic of debate. The first two Peking Man skulls were found in 1929 and three more in 1936. In the late 1930s, other pithecanthropine fossils were found in Java at Sangiran. It was clear to everyone else that all these fossils were very similar to Dubois' original find, but Dubois fiercely resisted this idea, claiming that they were all human in grade, while his, and only his, fossil filled the gap between humans and apes. In an effort to differentiate Java Man from these later finds, Dubois emphasized the apelike characteristics of his fossil, giving rise to the common myth that he had decided Java Man was just a gibbon, and had abandoned his claim for its intermediate status.