observatories—the Harvard College Observatory at Arequipa, Peru; the Lowell Observatory in Flagstaff, Arizona; and the Steward Observatory at the University of Arizona in Tucson—before he became involved in archaeology.

Douglass’s interest in the effects of sunspots on terrestrial weather led him to investigate the annual growth layers of Arizona pines for variations in tree-ring width. He discovered a relationship between rainfall and tree growth, and between cyclical variations in tree growth and sunspot cycles. Looking for extensive tree-ring records to substantiate his theories, Douglass asked archaeologists in Tucson for pieces of wood from the ruins of a southwestern pueblo. Within a decade he was able to date some of these wooden remains back to a.d. 100, and others to a.d. 700, providing archaeology with a valuable tool for establishing an independent chronology. Douglass went on to develop the study of tree-rings into the science of dendrochronology. Tree-ring dating has made substantial contributions to archaeology in the Arctic, Britain, Central Europe, and the Mediterranean Basin. Douglass also provided dendro-climatic and dendro-environmental reconstructions for archaeology.

He retired from astronomy to found and direct the Laboratory of Tree-ring Research at the University of Arizona, which he helped to establish as the preeminent center for dendrochronological research.

Tim Murray

Dubois, Eugene

(1858–1940)

Born in the netherlands, Dubois studied medicine at the University of Amsterdam until 1884. He worked as an assistant to the Anatomist Max Furbringer from 1881 until 1887, and lectured in anatomy from 1886 to 1887. Inspired by the work of Ernst Haeckel, Dubois resigned from the university and left for the Dutch East Indies (now indonesia) to search for evidence of early human beings. Haeckel had claimed that humankind had descended from a group of apes in Asia, and not in Africa as Darwin had suggested. This argument was based on a few anatomical resemblances between modern humans and the gibbons of island southeast asia.

Supported by the Dutch colonial government, Dubois searched for human ancestral remains in Java and Sumatra from 1888 to 1895. The skullcap, thighbone, and a few teeth of a Pithecanthropus erectus, along with other fossils, were found near the village of Trinil on Java between 1891 and 1893. Dubois believed these remains, known as “Java man,” to be the missing link between apes and humans, and he returned to Europe to convince the scientific community of their importance.

Dubois’s fossil finds were the first hominid remains to be accepted as material proof of human evolution, and a significant number of scientists regarded them as proof of a chain of connection between humans and their primitive ancestors. The debate about their significance led to the development of an evolutionary interpretation of extant European Neanderthal remains, leading to further development of the new science of paleoanthropology.

Dubois became professor of crystallography, mineralogy, paleontology, and geology at the University of Amsterdam in 1899 and withdrew from the debate on Pithecanthropus. He continued with paleontological and anatomical research, pioneering allometric relations between brain and body size in vertebrates and hominids. This work convinced him that vertebrate evolution had not proceeded in a linear nor a gradual way, but through quantum changes. He maintained that Pithecanthropus was the missing link between primates and hominids, and he would not accept that other pithecanthropine finds, made in Java in the 1930s by von Koenigswald, were much closer to Homo sapiens that he had originally argued. He retired in 1929.

Tim Murray

References

Theunissen, Bert. 1989. Eugene Dubois and the Ape-Man from Java: The History of the First Missing Link and Its Discoverer. Dordrecht; Boston: Kluwer Academic Publishers.