He was a physician, anthropologist, anatomist, paleontologist and ecologist. He was stubborn, intelligent, hardworking and extremely driven. From the time he was young, Eugène Dubois had one big goal in mind:to find the fossil intermediate between man and ape.
The Dutchman Marie Eugène Franҫois Thomas Dubois (1858-1940) went in search of the missing link, the intermediate form between man and ape that Charles Darwin and Ernst Haeckel speculated about.
In 1891 and 1892 he found a skull cap, a molar and a femur which he attributed in 1894 to the hominid Pithecanthropus erectus . His goal was achieved, but much criticism followed. The importance of his discovery was disputed by many colleagues.
Today, the fossils Dubois found are classified as Homo erectus counted. Even though we now know that the origin of man lies in Africa and that Dubois's find was not the intermediate form he was looking for, his discovery was the start of a huge increase in research into, and knowledge about, evolution. of man.
Mr Dubois, you grew up in beautiful South Limburg. How has that affected your career?
I think that was of great influence. I grew up surrounded by nature and had a great interest in nature from an early age. I took trips in the area, explored the caves of the St. Pietersberg and learned a lot about different species of plants and animals. I even had my own cabinet of curiosities, did you know that? Well, when I was ten, I first heard about Darwin's theory of evolution. I read the works of Compte de Buffon, Darwin, Thomas Huxley and Haeckel. This captivated me by the enigma of the origin of man. If man and ape were related, as Darwin suggested, then the remains of an intermediate form had to be found somewhere. I already decided then that I wanted to find it.
Yet you went on to study Medicine at the University of Amsterdam. Why the choice?
My father was a pharmacist and wanted me to succeed him. My teachers at the Hogere Burgerschool in Roermond thought a study of medicine would suit me better. Because I would also be taking a lot of anatomy courses, I chose that. Then I was also a bit in the direction of my father's field of expertise. In 1884 I completed my studies and I received an offer from Utrecht University to work as a teacher. However, my anatomy teacher Max Fürbringer encouraged me to go into the research. I had been working as his assistant for several years by then. I chose science and did extensive anatomical research on the larynx of various vertebrate species and formulated my own hypothesis about the evolution of this organ. Unfortunately, Fürbringer did a good job with my results and I decided to follow my original dream:to find the intermediate form between man and ape. In 1887 I went to the Dutch East Indies with my wife and newborn daughter.
How did you come up with the idea to look for the intermediate form precisely there?
Darwin had written that the ancestor of man must have lived in the tropics, since the great apes still live there today; the chimpanzee and gorilla in Africa and the orangutan and gibbon in Southeast Asia. I also corresponded with Ernst Haeckel on this subject and he advised me to look in the south of Asia. I decided to travel to Sumatra because there were many gibbons and orangutans there.
And, if I may be so bold, how could you afford such a long journey as a recent graduate?
I came up with a clever plan for that, if I do say so myself. You must not forget that I graduated as a doctor, so I was able to enter the service of the Royal Netherlands East Indies Army as a tropical doctor. That way I didn't have to pay the crossing. Once in Sumatra I started looking for fossils in caves, because in Europe human fossils had been found in caves. I found a lot of animal fossils, from pigs, rhinoceroses, deer, gibbons, to those of elephants and tapirs. But no humanoids. When I heard about a fossil human skull found in Java, I decided to go there.
You were assigned to the army as a tropical doctor, how come you had so much time to search for fossils?
Again by a rather cunning plan of mine. I had written a letter to the Indies authorities pointing out to them that the Netherlands was lagging far behind in the field of scientific research in the colonies. The English did much more research in their areas. I offered to do that research. That letter was effective because I was released from my medical work and was able to join the colonial Department of Education, Religion and Industry as a naturalist. That suited me much more because I didn't like the straitjacket of the army at all, I had a hard time obeying. The authorities gave me forty coolies (Indonesian workers, ed. ) assigned to help me in my search.
In Java you decided to do something that hadn't been done before, you stopped exploring caves and started digging. How did you arrive at that?
Geologists and naturalists who visited the island before me had discovered many fossils in rock layers. Because of this, it seemed logical to me to look a little more in open fields. Soon we found a lot of fossil remains of extinct fauna. That gave me courage that I would also find remains of humanoids.
Your great discoveries soon followed, tell us about them.
The excavations started in 1891 and soon I found a fossil molar. It looked very much like a molar found just before that in India and was attributed to a monkey. I therefore assumed that this molar must also have belonged to a monkey. A month later, my coolies found a skull cap. This one also looked very monkey-like. From the shape I could deduce that this must have had very thick eyebrow arches above the eyes. And the skullcap had covered a modest brain volume, about a thousand cubic centimeters. That was more than that of a monkey, but less than man. However, I still thought it was an ape-like one. It wasn't until I found the femur a year later that I realized it. That femur indicated that the "monkey" had walked upright. In 1894 I published about my find and named the species Pithecanthropus erectus, which means upright ape-like man.
You were lucky to find that femur, weren't you?
You can say that! Although I also just worked hard. In total, me and my coolies excavated forty thousand fossils, the largest collection of fossils from Indonesia in the world. These three bones were the only three bones of human ancestors. If I had not found that femur, I could not have imagined that the 'monkey' had walked upright and therefore could not draw the correct conclusion.
How were the reactions to your publication about the intermediate form?
Foolishly, they were quite dismissive. After the finds, I traveled back to the Netherlands to show my fossils to other scientists. But people did not understand that I wrote that the three finds belonged to the same species. Only the femur, they wanted to believe was "human." Conventions even voted for or against me! After the German anatomist Gustav Schwalbe gave an extensive description of my published fossils, I decided not to show them to others. I started working as a professor at the University of Amsterdam, where I researched differences in brain contents of different animal species. In doing so, I discovered that when the weight of the brain is taken in relation to the total weight of the animal, there are often leaps and bounds between species. I found that the brain size of great apes is about four times smaller than that of humans, and my Pithecanthropus erectus or java humans were right in the middle! Even more proof that I am right.
In recent years you have focused more on work other than the evolution of man, if I have understood correctly. What do you usually do?
Oh, so much. Among other things, I did research on the Limburg Early Pleistocene clay from Tegelen and the fossils in it. The fossil plants I found showed that Limburg had a much warmer climate two million years ago than it is today. I also mapped the prehistoric fauna of Limburg. On my own estate, De Bedelaer, I conduct experiments into the effect of introducing new species into an area. My son, an explorer, sends me exotic seeds from all kinds of tropical countries.
My goal is to make nature a little more varied in the Netherlands. That is why I was closely involved in the establishment of the Dutch Association for the Preservation of Nature Monuments. By the way, I am also curator of the Teylers Museum, you should visit there soon, then I can show you some of my accumulated collection.