Oakley, Kenneth Page
OAKLEY, KENNETH PAGE
b. Amersham, Buckinghamshire, United Kingdom, 7 April 1911; dOxford, United Kingdom, 2 November 1981)
geology, paleontology, anthropology.
Oakley is best known for his role in dismantling the Piltdown forgery. The fossil cranium, jaw, and teeth supposedly discovered in a quarry in Piltdown, Sussex (England), had significantly influenced the British anthropological community’s outlook on human evolution. Oakley’s pioneering work in the advancement of reliable dating techniques set the final blow to the chimera of a modern human skull and an orangutan jaw, and was invaluable for the much-needed setting-straight of the fossil hominid record at the time. Oakley’s work on relative and absolute dating represents a milestone in the history of paleoanthropology. His other interests were archaeology and folklore, with a primary focus on the culture of fossil hominids from a paleontological viewpoint. He carried out fieldwork in eastern and southern Africa.
Geological Survey and British Museum He was born the son of Tom Page Oakley, a physician and onetime headmaster of Amersham Grammar School. He was educated at Halloner’s Grammar School and studied geology and anthropology at University College London. Shortly after earning his BSc in 1933 he joined the Geological Survey (1934). In 1935, he was appointed assistant keeper of paleontology in the Department of Geology of the British Museum of Natural History in South Kensington, London. Three years later he received his PhD for his work on Silurian Pearl Bearing Bryozoa (Polyzoa). His early scientific papers concentrated on corals, sponges, and bryozoa, and included the regional guide to the Central England District in the British Regional Geology Series. In 1941 he married Edith Margaret Martin; they had two sons.
Oakley’s career in the British Museum was significantly interrupted only by World War II, during which he served in the Geological Survey. However, his work there on natural sources of phosphate for fertilization triggered an interest in mineralogy that would prove central to his scientific contributions to the problem of dating. After the war, Oakley was made senior principal scientific officer (1947) at the British Museum. In 1954, he became director of the Anthropological Sections of the Departments of Geology and Zoology, and the following year he was promoted to senior principal scientific officer.
Oakley wrote The Succession of Life through Geological Time (1948) and Man the Tool-Maker(1949). Such British Museum handbooks were seen as expositions of orthodox thinking and, since they were written for a lay public, they were meant to provide an overview of the fundamentals in a clear and simple style. The first-mentioned volume presented an account of the major steps in the evolution of the animal and plant kingdoms, and it also served as a guide to the exhibits on the succession of life in the museum’s Gallery V. The description of each geological period was split into several subdivisions: name, duration, geographical conditions, life in the sea, and life on land. These were summarized in a chart of the geological timescale.
Oakley’s latter volume represented a guide to the early human artifacts displayed in the Central Hall at the British Museum (Department of Geology), for which he was largely responsible. In nine sections, Man the Tool-Makerdealt with human antiquity, the origins of tool making, the question of raw materials, technology, an outline of the cultural sequence in relation to geology, the evolution of Paleolithic cultures, implements associated with fossil hominids, and considerations of some of the attributes of “man the tool-maker.” The booklet thus provided an introduction to Stone Age history and technology from a paleontologist’s point of view (the larger Paleolithic collections of the Bloomsbury Museum pertained to the Department of British Antiquities). It was meant to be complementary to Wilfrid Edward Le Gros Clark’s museum publication, History of the Primates(1949), which treated the biological aspects of human evolution. As such, Oakley regarded it as indispensable in providing a full picture of humans as social animals, who distinguished themselves from the rest of the animal kingdom through culture. As toolmakers, humans had acquired a marked capacity for conceptual thought (as opposed to the perceptual thinking of other primates).
Oakley’s views on the evolution of culture were summarized in a table attached to the appendix. The main division of cultures was based on the presence or absence of hand axes, which seemed to be associated with two evolutionary lineages, with the “handaxe peoples” (Swanscombe and Upper Paleolithic “races”) more closely related to Homo sapiens than the “flake-tool users” of Eurasia (Pithecanthropids, Neanderthaloids). Oakley described the development, migrations, and blending of these cultural stems in each of the three continents of the Old World. This was correlated to the development, migrations, and intermixture of hominid stems established on the basis of genetic principles, particularly blood-group data. All in all, although the book was seen as a textbook, it is not an easy read, as it presupposes knowledge in physical anthropology and genetics. Some of the orthodoxy of the views associated with the museum handbooks might be visible in Oakley’s description of living and fossil “races;” for example, the South African Bushmen were seen as the degenerate descendants of the “big-brained Boskop race.”
In other respects, Oakley’s work was far from orthodox, and his development of dating techniques came at an opportune moment in the history of paleoanthropology. Remains of so-called Piltdown Man had been discovered by the local solicitor and amateur geologist Charles Dawson and others in a gravel pit at Piltdown in Sussex, England. During the years of 1911 and 1912, several cranial fragments and the right half of a mandible containing molar teeth were reportedly unearthed. While the mandible was apelike, the braincase was modern looking. It therefore seemed that already at the Pliocene-Pleistocene boundary there had existed a human type with essentially modern skull size. Piltdown thus supported the widespread assumption that the expansion of the brain had preceded the acquisition of a fully upright posture in the course of human evolution.
This put into question the ancestral status of the already known fossil hominids such as Pithecanthropus erectus(today Homo erectus) from Java, consisting of a femur, calvaria, and some teeth discovered by the Dutch physician Eugène Dubois at Trinil in 1891 and 1892. Pithecanthropus seemed to date from about the same period as Piltdown Man, but was less modern in brain anatomy. Piltdown also worked against the acceptance of the small-brained australopithecines, which began to be discovered in southern Africa from the mid-1920s onward, as anything but fossil apes. The forgery was eventually removed from the fossil record in part because of revolutionary inventions in dating technology that were driven by Oakley, who began to work on a chemical technique of relative dating in 1947.
Relative Dating and Debunking Piltdown Oakley’s war-related work on the distribution of phosphates led to his engagement with the problem of dating fossil human remains. Inspired by the work of the French mineralogist
A. Carnot (1893), which built on insights of fluorine accumulation in bone and tooth that had begun to be gained earlier in the century, Oakley examined the uptake of fluorine by bone and confirmed that the amount of fluorine was correlated with the length of time it had been buried. Fluorine is absorbed from groundwater or moist sediments through irreversible ionic interchange with hydroxyl, transforming hydroxyapatite [Ca10(PO4)6.(OH)2] into fluorapatite [Ca10(PO4)6.F2].
However, since the uptake of fluorine depends on many variables, including the amount of fluorine in the groundwater, the numbers could not be calibrated against an absolute timescale. Rather, they provided what Oakley referred to as relative dating. Relative dating through the determination of the chemical composition of human remains in comparison with the chemical composition of other bones from the same deposit could answer the often vexing question of whether the human bones were original to that deposit or intrusive, for instance, due to the human habit of burying their dead, through which bones are brought into earlier deposits (Oakley, 1948a).
In 1932, Louis S. B. Leakey discovered the Kanam jaw and several teeth (Homo kanamensis after Leakey) at Lake Victoria in western Kenya. The Homo sapiens–like remains of supposedly Early Pleistocene age supported Leakey’s belief that the human ancestral line went as far back as the Miocene and did not include the australopithecines. As such, he hailed Kanam Man as the earliest known human ancestor (Leakey, 1934). However, Leakey did not appear to have followed the careful excavation procedures required of a field scientist, which damaged
both his and Kanam Man’s reputation. In January 1947, Oakley attended the first Pan-African Congress on Prehistory in Nairobi, Kenya, where Leakey’s Kanam Man was discussed. Subsequently, Oakley submitted the Kanam find to the fluorine technique, but the results were inconclusive due to the high background fluorine of the Kenyan material.
Nonetheless, Oakley remained convinced of the method’s value, and a breakthrough came the following year with the application of the fluorine technique to the controversial Galley Hill remains (1888), which had been used in support of the idea of a great antiquity of modern human morphology. In particular, the powerful anatomist Sir Arthur Keith, the onetime conservator of the Museum of the Royal College of Surgeons, had built his presapiens theory on this and other European finds of uncertain age, and saw in Galley Hill one of the proofs for long independent evolution of the modern human “races.”
In a coauthored paper, Ashley Montagu, professor of anthropology at Rutgers University, New Brunswick (New Jersey), demonstrated that morphologically, the Galley Hill skull and mandible possessed no features which could not be matched in the contemporary population of Britain. While this would not have thwarted Keith’s concept of a great age of relatively modern human anatomy, Oakley carried out a comparative fluorine analysis of the Galley Hill skeleton and Swanscombe skull, which had been found in similar geological circumstances in gravels at Swanscombe, East Kent, England (1935). He concluded that, contrary to the Swanscombe specimen, which was shown to be original to the Middle Pleistocene gravels of the Thames terrace, the Galley Hill skeleton was probably an intrusive burial of no great antiquity—i.e., Holocene (Oakley and Montagu, 1949).
Subsequently, Oakley was able to remove several specimens from the list of Paleolithic European remains or at least cast doubt on their place in it. Among these were the Fontéchevade skulls (modern-looking cranial remains from the Charente, France, discovered by Germaine Henri-Martin in 1947), which Oakley demonstrated to be younger than Swanscombe; the Moulin-Quignon jaw (Abbeville, France, 1863), already established as a fraud by some of the pioneers of human antiquity in the nineteenth century, confirmed by Oakley to be truly intrusive in the Middle Pleistocene gravel from which it had supposedly been taken; and the so-called Lloyd skull from the Thames Valley, London, which Oakley demonstrated to be in all likelihood of a later date than the associated Pleistocene fauna (Oakley, 1951).
In collaboration with the Department of the Government Chemist, Oakley then subjected the Piltdown remains to relative dating by fluorine content analysis. The results suggested that the cranium and jaw belonged to a single individual, which had been questioned by some anthropologists from the time of their discovery, but also that the find was much younger than claimed. The low fluorine content of the bones and teeth attributed to Piltdown showed that they did not belong to the Lower Pleistocene group of animal bones from the site (Oakley and Hoskins, 1950). However, many anthropologists took Oakley’s result as reason to distrust the technique rather than the age of the fossils. Nonetheless, an ape-man chimera in England seemed even less likely at a younger date, so that Oakley’s work prompted Joseph Sidney Weiner (1915–1982), then reader of physical anthropology at Oxford University, to instigate a full-scale reinvestigation into the site and its remains.
This included not only fluorine-content analysis, but also the determination of organic content in the form of nitrogen. The nitrogen of bones and teeth is part of the protein collagen that forms the organic matrix on which the phosphatic mineral matter has been deposited in growth. The collagen fibrils usually denature over time and nitrogen is constantly lost. Relative nitrogen dating had been carried out on the Cro-Magnon skeletons discovered by Édouard Lartet at Aurignac (Haute-Garonne, southern France) in 1860. Since Lartet’s judgment that the human bones were contemporaneous with the Pleistocene fauna from the cave was disputed, he had samples of both analyzed for nitrogen content. While it had long been known that the “animal matter” of bones decreases with the time they spend underground, this was probably the first instant of the nitrogen test being used for a comparative analysis. Lartet was proven correct by the results, which were, however, not generally regarded as conclusive.
The combination of the methods of relative dating of fluorine and nitrogen demonstrated that the age of the Piltdown jaw and cranium differed. This finding corroborated Weiner’s discovery that they had been deliberately stained and the teeth artificially remodeled to give the impression of great age and humanlike abrasion. The report dismissed the Piltdown jaw as that of a modern ape fraudulently treated to match the skull (Weiner, Oakley, and Clark, 1953). Further systematic inquiry made clear that the cranium also had been planted at the site and was not a genuine fossil, that indeed the entire Piltdown assemblage was forged (Weiner, 1955, and Oakley, Weiner, et al., 1955).
At the time of the final dismantling of the Piltdown forgery, the weird association of orangutan jaw and human skull had been worked with by anthropologists for several decades. Getting rid of it demanded a coordination of efforts. As Oakley put it,
[a]lthough it was the application of the “fluorine test” to the Piltdown specimens in 1949 that triggered off the extensive investigations which eventually led to this result, the removal of all doubt about its correctness was due to teamwork on a scale probably unprecedented in solving a single problem. Thus a whole battery of physical and chemical techniques was brought to bear on the Piltdown problem before complete proof was obtained that the Piltdown skulls I and II and all the mammalian fossils recovered from Site I and Site II were part of an elaborate forgery. Some 25 scientists deserve credit for their contributions to this work. (1980, p. 52)
At the time of the Piltdown investigation, however, radiocarbon dating was not considered a possible test of the Piltdown remains because it would have meant destroying the specimens in order to obtain the quantity of carbon needed. In contrast to fluorine and nitrogen dating, radiocarbon dating is an absolute, or chronometric, dating technique that assigns a specimen an age in years. Only in 1959, when the radiocarbon-dating technique had been refined and smaller samples were sufficient, did a radiocarbon analysis provide a Holocene date for both cranium and mandible (Oakley and de Vries, 1959).
Oakley’s involvement in the debunking of the Piltdown forgery turned him into a name in the scientific communities the world over. It also helped to establish anthropology as a subject in the British Museum, and in 1959, the Subdepartment of Anthropology was created as a consolidation of the Anthropological Sections; it was attached to the Department of Palaeontology. In fact, Oakley had hoped for the foundation of a separate Department of Anthropology, but it did not materialize. He did succeed, however, in securing new staff with an interest in human variability and paleoserology, in establishing important collections of casts and artifacts, and in greatly expanding the existing collections of comparative material.
Frameworks Oakley’s pioneering work on fossil dating culminated in Frameworks for Dating Fossil Man (1964b). The book is divided into two parts: the first dealing with stratigraphic dating and the second with archaeological dating, that is, the use of artifacts as index fossils and the succession of cultures and events in Europe, Africa, and Asia. Among the stratigraphic dating sources are evidence of glaciers, fossil pollen, bones of extinct animals, and deep-sea cores. These were brought in association with Paleolithic cultures. In the second part Oakley followed the general postsynthesis trend of accepting only two genera in the Hominidae, Homo and Australopithecus, the acceptance of the latter into the hominid line having been catalyzed by the exposure of the Piltdown forgery, among other things. From his vantage point of geological as well as archaeological training, he also provided the ecological background essential to understanding early hominid behavior. The work ends with a listing of the then known fossil hominids and their dating in terms of the various frameworks developed throughout the book.
In the course of time, Oakley and others developed an entire system of relative dating, combining the analysis of fluorine and nitrogen of bone, antler, or dentine, with the determination of uranium contents. The uranium content—uranium is also absorbed from groundwater by the apatite of bone or tooth—could be assessed by a radio-metric assay, which meant exposing a sample to a Geiger counter screened in a lead chamber and counting its B—radiations per minute. This method had the advantage of the specimen not being damaged, if it could fit into a 4 by 3 by 2 centimeter space.
Oakley also introduced a terminology for different kinds of dating (at the Wenner-Gren Symposium in New York in 1952). The first level of relative dating consisted of determining the chemical composition of human remains in comparison with the chemical composition of other bones from the same deposit to find out whether the human bones were intrusive or contemporaneous (called R.1 dating). Once contemporaneity was established, a human fossil bone could be associated with paleontological, geological, or archaeological markers from the same deposit, thereby allocating the specimen to a stage in the local sequence of deposits, faunas, and/or cultures (called R.2 dating). While referring a human bone to a certain cultural environment such as the Aurignacian was R.2 dating, its placement within worldwide and wide-scale systems, such as the sequence of cold and interstadial phases in the European Pleistocene, was considered R.3 dating.
Similarly, absolute dating methods could consist in the direct measurement of the carbon-14 radioactivity of the bone under consideration (invented in the 1950s by Willard Frank Libby), which Oakley termed A.1, or the age of the source deposit could be determined through measurement of its potassium-argon ratio (if it contained potassium) and associated bones, shells, or charcoal could be radiocarbon dated (A.2). Furthermore, the source bed might be correlated to a deposit of known age (A.3), or the age in years of the source bed might be inferred from knowledge of climatic fluctuations (A.4) (Oakley, 1964a, 1964b).
The prospect of reliable dating techniques seemed even more important to paleoanthropology than getting rid of the Piltdown fossils that had come to stand squarely in almost all hominid phylogenies. Triggered by the success of the dating techniques with regard to the Piltdown material, the Wenner-Gren Foundation granted Oakley financial support for applications of the combination of fluorine, uranium, and nitrogen dating procedures to approximately one thousand skeletal parts from Europe, Africa, the Americas, Asia, Australia, Indonesia, Malaysia, and the Pacific Islands. This was done in cooperation with museum curators, scientists, and laboratories. A slip-index databank containing information on the dating and the name of the responsible analyst and laboratory was compiled at the British Museum (Oakley, 1980).
Oakley’s dating efforts were also associated with another of his great achievements during the stewardship of the Subdepartment of Anthropology, that is the compilation of the Catalogue of Fossil Hominids with Bernard Grant Campbell and Theya Ivitsky Molleson that was financially aided by the Wenner-Gren foundation (1967, 1971, 1975). It is still a valuable reference work. Due to the great progress made in fossil discoveries, in analysis of associated fauna and industries, and in stratigraphy and dating methods since the Catalogue des hommes fossiles by Henri Victor Vallois and Hallam Leonard Movius in 1953, the new catalog was greeted with much welcome. Specialists were responsible for individual entries on fossils from particular regions. Where available, each specimen was accompanied by information on place and date of discovery and name of discoverer, on the geological nature of the deposit, its stratigraphic age, and on faunal and archaeological contexts. Furthermore, essential literature, present repository, and availability of molds, as well as reference designation (museum registration number) and anatomical inventory were provided. A novelty with respect to its predecessor was the inclusion of information on relative and absolute dating according to the specific framework of types of dating developed by Oakley.
It is not a surprise that the scientist who helped to remove the Piltdown obstacle to a redrawing of the human family tree had already been honored in many ways during his lifetime. After all, with the Piltdown chimera gone and the acceptance of the australopithecines as hominids, bipedalism rather than brain expansion came to be viewed as early hominid adaptation, and Africa rather than Asia was confirmed as the most likely cradle of humankind. Oakley received the Wollaston Fund Award in 1941, and the Prestwich Medal of the Geological Society in London in 1963. In 1953 he was elected Fellow of the Society of Antiquaries, and in 1957 he became a Fellow of the British Academy of Science. He was president of the Anthropological Section of the British Association for the Advancement of Science in 1961. Oakley continued to publish after his retirement from the British Museum in 1969 due to multiple sclerosis, leaving behind a publication list of over one hundred items, among them his last book, The Decorative and Symbolic Uses of Vertebrate Fossils (1975).
BIBLIOGRAPHY
WORKS BY OAKLEY
With J. Desmond Clark, L. H. Wells, and J. A. McClelland. “New Studies on Rhodesian Man.” Journal of the Royal Anthropological Institute of Great Britain and Ireland 77, no. 1 (1947): 7–32.
“Fluorine and the Relative Dating of Bones.” Advancement of Science 4 (1948a): 336–337.
With Helen M. Muir-Wood. The Succession of Life through Geological Time. London: British Museum (Natural History), 1948b. 7th ed. 1967.
Man the Tool-Maker. London: British Museum (Natural History), 1949. 6th ed. Chicago: University of Chicago Press, 1976.
With Montague Francis Ashley Montagu. “A Re-Consideration of the Galley Hill Skeleton.” Bulletin of the British Museum (Natural History), Geology Series 1, no. 2 (1949): 25–48.
With C. R. Hoskins. “New Evidence on the Antiquity of Piltdown Man.” Nature165 (1950): 379–382.
“The Fluorine-Dating Method.” Yearbook of Physical Anthropology 5 (1951): 44–52.
With Joseph S. Weiner and Wilfrid Edward Le Gros Clark. “The Solution of the Piltdown Problem.” Bulletin of the British Museum (Natural History), Geology Series 2 (1953): 141–146.
With Joseph Weiner, et al. “Further Contributions to the Solution of the Piltdown Problem.” Bulletin of the British Museum (Natural History), Geology Series 2 (1955): 225–287.
With H. de Vries. “Radiocarbon Dating of the Piltdown Skull and Jaw.” Nature 184, no. 4682 (1959): 224–226.
Frameworks for Dating Fossil Man. Chicago: Aldine, 1964a. 2nd ed. 1966. 3rd ed. London: Weidenfeld & Nicolson, 1969.
“The Problem of Man’s Antiquity: An Historical Survey.” Bulletin of the British Museum (Natural History), Geology Series, 9, no. 5 (1964b): 83–155.
With Bernard Grant Campbell. Catalogue of Fossil Hominids. Part. I: Africa. London: British Museum (Natural History), 1967.
“The Date of the ‘Red Lady’ of Paviland.” Antiquity 42 (1968): 306–307.
With Bernard Grant Campbell and Theya Ivitsky Molleson. Catalogue of Fossil Hominids. Part II: Europe. London: British Museum (Natural History), 1971.
The Decorative and Symbolic Uses of Vertebrate Fossils. London: Oxford University Press, 1975.
With Bernard Grant Campbell and Theya Ivitsky Molleson. Catalogue of Fossil Hominids. Part III: Americas, Asia, Australasia. London: British Museum (Natural History), 1975.
“Relative Dating of the Fossil Hominids of Europe.” Bulletin of the British Museum (Natural History), Geology Series34, no. 1 (1980): 1–63.
OTHER SOURCES
Carnot, A. “Recherches sur la composition générale et la teneur en fluor des os modernes et des os fossiles des différents âges.” Annales de Mineralogie Paris 3 (1893): 155–195.
Clark, Wilfrid Edward Le Gros. History of the Primates: An Introduction to the Study of Fossil Man. London: Printed by order of the Trustees of the British Museum, 1949.
Leakey, Louis S. B. Adam’s Ancestors: An Up-to-Date Outline of What Is Known about the Origin of Man. London: Methuen, 1934.
Molleson, Theya. “K. P. Oakley.” RAIN 48 (1982): 15–16. Vallois, Henri Victor, and Hallam Leonard Movius. Catalogue des hommes fossiles. Algeria: Publication of the Nineteenth International Geological Congress, 1953.
Weiner, Joseph Sidney. The Piltdown Forgery. London: Oxford University Press, 1955.
Marianne Sommer