Leakey, Richard Erskine Frere (1944 – ) African-Born English Paleontologist and Anthropologist

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Richard Erskine Frere Leakey (1944 – )
African-born English paleontologist and anthropologist

Richard Erskine Frere Leakey was born on December 19, 1944, in Nairobi, Kenya. Continuing the work of his parents, Leakey has pushed the date for the appearance of the first true humans back even further than they had, to nearly three million years ago. This represents nearly a doubling of the previous estimates. Leakey also has found more evidence to support his father's still controversial theory that there were at least two parallel branches of human evolution , of which only one was successful. The abundance of human fossils uncovered by Richard Leakey's team has provided an enormous number of clues as to how the various fossil remains fit into the puzzle of human evolution. The team's finds have also helped to answer, if only speculatively, some basic questions: When did modern human's ancestors split off from the ancient apes? On what continent did this take place? At what point did they develop the characteristics now considered as defining human attributes? What is the relationship among and the chronology of the various genera and species of the fossil remains that have been found?

While accompanying his parents on an excavation at Kanjera near Lake Victoria at the age of six, Richard Leakey made his first discovery of fossilized animal remains, part of an extinct variety of giant pig. Richard Leakey, however, was determined not to "ride upon his parents' shoulders," as Mary Leakey wrote in her autobiography, Disclosing the Past. Several years later, as a young teenager in the early 1960s, Richard demonstrated a talent for trapping wildlife , which prompted him to drop out of high school to lead photographic safaris in Kenya. His paleontological career began in 1963, when he led a team of paleontologists to a fossil-bearing area near Lake Natron in Tanganyika (now Tanzania), a site that was later dated to approximately 1.4 million years ago. A member of the team discovered the jaw of an early hominid—a member of the family of erect primate mammals that use only two feet for locomotion—called an Australopithecus boisei (then named Zinjanthropus ).) This was the first discovery of a complete Australopithecus lower jaw and the only Australopithecus skull fragment found since Mary Leakey's landmark discovery in 1959. Jaws provide essential clues about the nature of a hominid, both in terms of its structural similarity to other species and, if teeth are present, its diet. Richard Leakey spent the next few years occupied with more excavations, the most important result of which was the discovery of a nearly complete fossil elephant.

In 1964 Richard married Margaret Cropper, who had been a member of his father's team at Olduvai the year before. It was at this time that he became associated with his father's Centre for Prehistory and Paleontology in Nairobi. In 1968, at the age of 23, he became administrative director of the National Museum of Kenya.

While his parents had mined with great success the fossil-rich Olduvai Gorge, Richard Leakey concentrated his efforts in northern Kenya and southern Ethiopia. In 1967 he served as the leader of an expedition to the Omo Delta area of southern Ethiopia, a trip financed by the National Geographic Society. In a site dated to approximately 150,000 years ago, members of his team located portions of two fossilized human skulls believed to be from examples of Homo sapiens, or modern humans. While the prevailing view at the time was that Homo sapiens emerged around 60,000 years ago, these skulls were dated at 130,000 years old.

While on an airplane trip, Richard Leakey flew over the eastern portion of Lake Rudolf (now Lake Turkana) on the Ethiopia-Kenya border, and he noticed from the air what appeared to be ancient lake sediments, a kind of terrain that he felt looked promising as an excavation site. He used his next National Geographic Society grant to explore this area. The region was Koobi Fora, a site that was to become Richard Leakey's most important area for excavation. At Koobi Fora his team uncovered more than four hundred hominid fossils and an abundance of stone tools, such tools being a primary indication of the presence of early humans. Subsequent excavations near the Omo River in Kenya, from 1968, unearthed more examples of early humans, the first found being another Australopithecus lower jaw fragment. At the area of Koobi Fora known as the KBS tuff (tuff being volcanic ash; KBS standing for the Kay Behrensmeyer Site, after a member of the team) stone tools were found. Preliminary dating of the site placed the area at 2.6 million years ago; subsequent tests over the following few years determined the now generally accepted age of 1.89 million years.

In July of 1969, Richard Leakey came across a virtually complete Australopithecus boisei skull—lacking only the teeth and lower jaw—lying in a river bed. A few days later a member of the team located another hominid skull nearby, comprising the back and base of the cranium. The following year brought the discovery of many more fossil hominid remains, at the rate of nearly two per week. Among the most important finds was the first hominid femur to be found in Kenya, which was soon followed by several more. It was at about this time that Leakey obtained a divorce from his first wife, and in October of 1970, he married Meave Gillian Epps, who had been on the 1969 expedition.

In 1972, Richard Leakey's team uncovered a skull that appeared to be similar to the one identified by his father and called Homo habilis ("man with ability"). This was the early human that Louis Leakey maintained had achieved the toolmaking skills that precipitated the development of a larger brain capacity and led to the development of the modern human—Homo sapiens. This skull was more complete and apparently somewhat older than the one Louis Leakey had found and was thus the earliest example of the species Homo yet discovered. They labeled the new skull, which was found below the KBS tuff, "Skull 1470," and this proved to among Richard Leakey's most significant discoveries. The fragments consisted of small pieces of all sides of the cranium, and, unusually, the facial bones, enough to permit a reasonably complete reconstruction. Larger than the skulls found in 1969 and 1970, this example had approximately twice the cranial capacity of Australopithecus and more than half that of a modern human—nearly 800 cubic centimeters. At the time, Leakey believed the fragments to be 2.9 million years old (although a more recent dating of the site would place them at less than 2 million years old). Basing his theory in part on these data, Leakey developed the view that these early hominids may have lived as early as 2.5 or even 3.5 million years ago and gave evidence to the theory that Homo habilis was not a descendant of the australopithecines, but a contemporary.

By the late 1960s, relations between Richard Leakey and his father had become strained, partly because of real or imagined competition within the administrative structure of the Centre for Prehistory, and partly because of some divergences in methodology and interpretation. Shortly before Louis Leakey's death, however, the discovery of Skull 1470 by Richard Leakey's team allowed Richard to present his father with apparent corroboration of one of his central theories.

Richard Leakey did not make his theories of human evolution public until 1974. At this time, scientists were still grappling with Louis Leakey's interpretation of his findings that there had been at least two parallel lines of human evolution, only one of which led to modern humans. After Louis Leakey's death, Richard Leakey reported that, based on new finds, he believed that hominids diversified between 3 and 3.5 million years ago. Various lines of australopithecines and Homo coexisted, with only one line, Homo, surviving. The australopithecines and Homo shared a common ancestor; Australopithecus was not ancestral to Homo. As did his father, Leakey believes that Homo developed in Africa, and it was Homo erectus who, approximately 1.5 million years ago, developed the technological capacity to begin the spread of humans beyond their African origins. In Richard Leakey's scheme, Homo habilis developed into Homo erectus, who in turn developed into Homo sapiens, the present-day human.

As new finds are made, new questions arise. Are newly discovered variants proof of a plurality of species, or do they give evidence of greater variety within the species that have already been identified? To what extent is sexual dimorphism responsible for the apparent differences in the fossils? In some scientific circles, the discovery of fossil remains at Hadar in Ethiopia by archaeologist Donald Carl Johanson and others, along with the more recent revised dating of Skull 1470, cast some doubt on Leakey's theory in general and on his interpretation of Homo habilis in particular. Johanson believed that the fossils he found at Hadar and the fossils Mary Leakey found at Laetoli in Tanzania, and which she classified as Homo habilis, were actually all australopithecines; he termed them Australopithecus afarensis and claimed that this species is the common ancestor of both the later australopithecines and Homo. Richard Leakey has rejected this argument, contending that the australopithecines were not ancestral to Homo and that an earlier common ancestor would be found, possibly among the fossils found by Mary Leakey at Laetoli.

The year 1975 brought another significant find by Leakey's team at Koobi Fora: the team found what was apparently the skull of a Homo erectus, according to Louis Leakey's theory a descendent of Homo habilis and probably dating to 1.5 million years ago. This skull, labeled "3733," represents the earliest known evidence for Homo erectus in Africa.

Richard Leakey began to suffer from health problems during the 1970s, and in 1979 he was diagnosed with a serious kidney malfunction. Later that year he underwent a kidney transplant operation, his younger brother Philip being the donor. During his recuperation Richard completed his autobiography, One Life, which was released in 1984, and following his recovery, he renewed his search for the origins of the human species. The summer of 1984 brought another major discovery: the so-called Turkana boy, a nearly complete skeleton of a Homo erectus, missing little but the hands and feet, and offering, for the first time, the opportunity to view many bones of this species. It was shortly after the unearthing of Turkana boy—whose skeletal remains indicate that he was a twelve-year-old youngster who stood approximately five-and-a-half feet tall—that the puzzle of human evolution became even more complicated. The discovery of a new skull, called the Black Skull, with an Australopithecus boisei face but a cranium that was quite apelike, introduced yet another complication, possibly a fourth branch in the evolutionary tree. Leakey became the Director of the Wildlife Conservation and Management Department for Kenya (Kenya Wildlife Service) in 1989 and in 1999 became head of the Kenyan civil service.