Louis and Mary Leakey


Louis and Mary Leakey
Louis and Mary Leakey

Louis and Mary Leakey, two of the foremost fossil hunters of the twentieth century, are known for their many discoveries relating to early human evolution. Their finds at Olduvai Gorge, a site in northwestern Tanzania, when added to the prior work of Raymond Dart and Robert Broom, convinced most paleoanthropologists that humans originally evolved in Africa. For many years, especially after the discoveries of Homo erectus remains in Java, and in China at Zhoukoudian, the general belief among scientists had been that humans had come into being in Asia.

Born in British East Africa (now Kenya) in 1903, Louis ("L.S.B.") Leakey was the son of Christian missionaries. Since his family lived alongside the Kykuyu people that his parents were trying to convert, Louis grew up under conditions that many people would consider rough. His first home had a dirt floor and thatched roof. This early experience probably helped him bear up in the harsh environments where he later carried out his work.

He began his search at Olduvai in 1931. His quest for early human remains and artifacts continued there for the next forty years. Much of his time was spent at the now famous FLK site. An acronym for "Frida Leakey Korongo," it was named for his first wife (korongo is Swahili for gully).

Mary and Louis first became acquainted in the early thirties while she was working for him as an illustrator. They had an affair and were soon living together — at the time he was still married to Frida, with whom he had had a child. Frida divorced him in 1936. The resulting scandal ended his career at Cambridge.

paranthropus boisei
Paranthropus boisei, found by Mary Leakey

It was at the FLK site in 1959 that Mary found remains of the robust australopithecine Zinjanthropus boisei (now known as Paranthropus boisei). Louis was in camp with a fever at the time. The specimen's age of 1.75 million years radically altered accepted ideas about the time scale of human evolution. They also found and studied more than 2,000 stone tools and flakes at the site. Louis and Mary's son Jonathan also found the first specimen of Homo habilis, a jaw fragment, at Olduvai in 1960. Now officially designated as OH 7 ("Olduvai Hominid 7"), it is considered the type specimen for H. habilis.

In 1948, on Rusinga Island in Lake Victoria, Mary also discovered a near complete skull of Proconsul, a dryopithecine of Miocene age. Fossils attributed to this genus range from 27 to 17 million years in age. Animals of this type, in which no tail was present, mixed the traits of Old World monkeys and apes. A continuing controversy has existed over whether or not members of the genus Proconsul actually were apes. This is the view of some researchers. Others consider it a precursor of both Old World monkeys and apes.

Location of Olduvai Gorge
Location of Olduvai Gorge
Map: Sémhur

Olduvai Gorge
Olduvai Gorge
Map: Guston Sondin-Klausner

Proconsul, another of Mary Leakey's finds
Credit: Ryan Somma

Mary Leakey is also famed for her discovery of 3.5 million-year-old hominid footprints. The prints, which she found at Laetoli in Tanzania in 1974, were originally made in fresh layer of powdery volcanic ash. A light rain followed that cemented the ash without obscuring the prints, which were made by three individuals walking upright, possibly in a group. The footprints show that hominids even at that time walked upright — there are no knuckle-impressions like those of an ape. Nor do the feet have the mobile big toe of an ape. Rather, they have the same arched structure as those of modern humans. They are "perhaps the most remarkable find I have made in my entire career," she said in 1976. "When we first came across the hominid prints I must admit I

was skeptical, but then it became clear that they could be nothing else. They are the earliest prints of man's ancestors, and they show us that hominids three and three-quarter million years ago [the prints have since been more accurately dated to 3.5 mya] walked upright with a free-striding gait, just as we do today. [quoted in Milner (1993, p. 262)]

Mary Leakey originated many of the methods paleoanthropologists use today. She was the more systematic and logical member of the pair. The intuitive Louis would pick a site on a hunch and she would follow through with a meticulous search, often while he was away abroad raising money. Although Louis was often credited with their discoveries in the popular press, and is the one often pictured with their skulls, he never actually found a skull himself. But she later said that if both of them had been the same sort of person, they would never have accomplished so much.

As part of his research into early humans Louis wanted to collect more information on the behavior of living apes. To this end, he selected three young women Jane Goodall, Diane Fossey and Birutė Galdikas — all now famous — to study, respectively, chimpanzees, gorillas and orangutans in the wild.

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