Mary Leakey: Unearthing History

Editors' Note:
Mary Leakey, one of the world's most renowned hunters of early human fossils, died in Nairobi on December 9, 1996, at the age of 83. Crowning triumphs of her long career included such finds as the 1972 discovery (with Louis, her husband and collaborator) of 1.75-million-year-old remains from Homo habilis at Olduvai Gorge and the 1978 discovery of 3.6-million-year-old footprints at Laetoli, both in Tanzania.

This profile of Dr. Leakey, written by former news editor Marguerite Holloway, originally appeared in the October 1994 issue of Scientific American

Mary Leakey waits for my next question, watching from behind a thin curtain of cigar smoke. Leakey is as famous for her precision, her love of strong tobacco--half coronas, preferably Dutch--and her short answers as she is for some of the most significant archaeological and anthropological finds of this century. The latter would have hardly been excavated without her exactitude and toughness. And in a profession scarred by battles of interpretation and of ego, Leakey's unwillingness to speculate about theories of human evolution is unique.

These characteristics have given Leakey a formidable reputation among journalists and some of her colleagues. So have her pets. In her autobiography, Disclosing the Past, Leakey mentions a favorite dog who tended to chomp people whom the archaeologist didn't like, "even if I have given no outward sign." So as we talk in her home outside Nairobi, I sit on the edge of a faded sofa, smiling exuberantly at her two dalmatians, Jenny and Sam, waiting for one of them to bite me. I quickly note details--her father's paintings on the wall, the array of silver trophies from dog shows and a lampshade with cave painting figures on it--in case I have to leave suddenly. But the two dogs and soon a cat and later a puppy sleep or play, and Leakey's answers, while consistently private, seem less terse than simply thoughtful.

Leakey first came to Kenya and Tanzania in 1935 with her husband, the paleontologist Louis Leakey, and except for forays to Europe and the U.S., she has been there ever since. During those many years, she introduced modern archaeological techniques to African fieldwork, using them to unearth stone tools and fossil remains of early humans that have recast the way we view our origins. Her discoveries made the early ape Proconsul, Olduvai Gorge, the skull of Zinjanthropus and the footprints of Laetoli, if not household names, at least terms familiar to many.


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Leakey was born in England, raised in large part in France and appears to have been independent, exacting and abhorrent of tradition from her very beginnings. Her father, an artist, took his daughter to see the beautiful cave paintings at such sites as Fond de Gaume and La Mouthe and to view some of the stone and bone tools being studied by French prehistorians. As she has written, these works of art predisposed Leakey toward digging, drawing and early history: "For me it was the sheer instinctive joy of collecting, or indeed one could say treasure hunting: it seemed that this whole area abounded in obje cts of beauty and great intrinsic interest that could be taken from the ground."

These leanings ultimately induced Leakey at the age of about 17 to begin working on archaeological expeditions in the U.K. She also attended lectures on archaeology, prehistory and geology at the London Museum and at University College London. Leakey says she never had the patience for formal education and never attended university; she never attended her governesses either. (At the same time, she is delighted with her many honorary degrees: "Well, I have worked for them by digging in the sun.")

A dinner party following a lecture one evening led her, in turn, to Louis Leakey. In 1934 the renowned researcher asked Mary, already recognized for her artistic talents, to do the illustrations for a book. The two were soon off to East Africa. They made an extraordinary team. "The thing about my mother is that she is very low profile and very hard working," notes Richard E. Leakey, former director of the Kenya Wildlife Service, an iconoclast known for his efforts to ban ivory trading and a distinguished paleontologist. "Her commitment to detail and perfection made my father's career. He would not have been famous without her. She was much more organized and structured and much more of a technician. He was much more excitable, a magician."

What the master and the magician found in their years of brushing away the past did not come easily. From 1935 until 1959 the two worked at various sites throughout Kenya and Tanzania, searching for the elusive remains of early humans. They encountered all kinds of obstacles, including harsh conditions in the bush and sparse funding. Success too was sparse--until 1948. In that year Mary found the first perfectly preserved skull and facial bones of a hominoid, Proconsul, which was about 16 million years old. This tiny Miocene ape, found on Rusinga Island in Lake Victoria, provided anthropologists with their first cranium from what was thought to be the missing link--a tree-dwelling monkey boasting a bigger brain than its contemporaries.

Australopithecus boisei

Proconsul was a stupendous find, but it did not improve the flow of funds. The Leakeys remained short of financial support until 1959. The big break came one morning in Olduvai Gorge, an area of Tanzania near the Great Rift Valley that slices East Africa from north to south. Again it was Mary who made the discovery. Louis was sick, and Mary went out to hunt around. Protruding slightly from one of the exposed sections was a roughly 1.8-million-year-old hominid skull, soon dubbed Zinjanthropus. Zinj became the first of a new group--Australopithecus boisei--and the first such skull to be found in East Africa.

"For some reason, that skull caught the imagination," Leakey recalls, pausing now and then to relight her slowly savored cigar or to chastise a dalmatian for being too forward. "But what it also did, and that was very important for our point of view, it caught the imagination of the National Geographic Society, and as a result they funded us for years. That was exciting."

How Zinj fits into the family tree is not something Leakey will speculate about. "I never felt interpretation was my job. What I came to do was to dig things up and take them out as well as I could," she describes. "There is so much we do not know, and the more we do know, the more we realize that early interpretations were completely wrong. It is good mental exercise, but people get so hot and nasty about it, which I think is ridiculous."

I try to press her on another bone of contention: Did we Homo sapiens emerge in Africa, or did we spring up all over the world from different ancestors, a theory referred to as the multiregional hypothesis? Leakey starts to laugh. "You'll get no fun out of me over these things. If I were Richard, I would talk to you for hours about it, but I just don't think it is worth it." She pauses. "I really like to feel that I am on solid ground, and that is never solid ground."

Oldowan Tools

In the field, Leakey was clearly on terra firma. Her sites were carefully plotted and dated, and their stratigraphy--that is, the geologic levels needed to establish the age of finds--was rigorously maintained. In addition to the hominid remains found and catalogued at Olduvai, Leakey discovered tools as old as two million years: Oldowan stone tools. She also recorded how the artifacts changed over time, establishing a second form, Developed Oldowan, that was in use until some 500,000 years ago.

"The archaeological world should be grateful that she was in charge at Olduvai," notes Rick Potts, a physical anthropologist from the Smithsonian Institution who is studying Olorgesailie, a site about an hour south of Nairobi where the Leakeys found ancient stone axes in 1942. Now, as they did then, the tools litter the white, sandy Maasai savanna. The most beautiful ones have been stolen, and one of Leakey's current joys is that the Smithsonian is restoring the site and its small museum and plans to preserve the area.

Olduvai Gorge has not fared as well. After years of residence and work there, and after the death of Louis in 1972, Mary finally retired in 1984. Since then, she has worked to finish a final volume on the Olduvai discoveries and has also written a book on the rock paintings of Tanzania. "I got too old to live in the bush," she explains. "You really need to be youngish and healthy, so it seemed stupid to keep going." Once she left, however, the site was ignored. "I go once a year to the Serengeti to see the wildebeest migrations because that means a lot to me, but I avoid Olduvai if I can because it is a ruin. It is most depressing." In outraged voice, she snaps out a litany of losses: the abandoned site, the ruined museum, the stolen artifacts, the lost catalogues. "Fortunately, there is so much underground still. It is a vast place, and there is plenty more under the surface for future generations that are better educated."

Leakey's most dramatic discovery, made in 1978, and the one that she considers most important, has also been all but destroyed since she left the field. The footprints of Laetoli, an area near Olduvai, gave the world the first positive evidence of bipedalism. Three hominids (generally identified as Australopithecus afarensis ) had walked over volcanic ash, which fossilized, preserving their tracks. The terrain was found to be about 3.6 million years old. Although there had been suggestions in the leg bones of other hominid fossils, the footprints made the age of bipedalism incontrovertible. "It was not as exciting as some of the other discoveries, because we did not know what we had," she notes. "Of course, when we realized what they were, then it was really exciting."

Today the famous footprints may only be salvaged with the intervention of the Getty Conservation Institute. "Oh, they are in a terrible state," Leakey exclaims. "When I left, I covered them over with a mound of river sand and then some plastic sheeting and then more sand and a lot of boulders on top to keep the animals off and the Maasai off." But acacia trees took root and grew down among the tracks and broke them up.

Although Leakey steers clear of controversy in her answers and her writings, she has not entirely escaped it. She and Donald Johanson, a paleontologis t at the Institute of Human Origins in Berkeley, Calif., have feuded about the relation between early humans found in Ethiopia and in Laetoli. (Johanson set up his organization as a philosophical counterweight to the L.S.B. Leakey Foundation.) And some debate erupted about how many prints there were at Laetoli. Tim White of the University of California at Berkeley claimed that there were only two and that Leakey and her crew had made the other track with a tool during excavation. Leakey's response? "It was a nonsense," she laughs, and we are on to the next subject.

A subject Leakey does not like. "'What was it like to be a woman? A mother? A wife?' I mean that is all such nonsense," she declares. Leakey--like many other female scientists of her generation, including Nobel laureates Rita Levi-Montalcini and Gertrude Belle Elion--dislikes questions about being a woman in a man's field. Her sex played no role in her work, she asserts. She just did what she wanted to do. "I was never conscious of it. I am not lying for the sake of anything. I never felt disadvantaged."

Leakey just did her work, surviving bitter professional wars in anthropolog y and political upheavals. In 1952 Louis, who had been made a member of the Kikuyu tribe during his childhood in Africa, was marked for death during the Mau Mau uprising. The four years during the height of the rebellion were terrifying for the country. The brakes on Mary's car were tampered with, and a relative of Louis's was murdered. The house that Leakey lives in today was designed during this time: a low, white square structure with a central courtyard where the dogs can run at night.

These pets are very important to Leakey--a source of companionship and safety out in the bush. She admires the traits in them that others admire in her: independence and initiative. (Any small joy that I have about emerging from her house unbitten fades sadly when I reread the section in her autobiography about her telepathic dalmatian and learn that he died years ago.)

We seem to have covered everything, and so she reviews her discoveries aloud. "But you have not mentioned the fruits," she reminds me. One of Leakey's favorite finds is an assortment of Miocene fossils: intact fruits, seeds, insects--including one entire ant nest--and a lizard with its tongue hanging out. They lay all over the sandy ground of Rusinga Island. "We only found them because we sat down to smoke a cigarette, hot and tired, and just saw all these fruits lying on the ground next to us. Before that we had been walking all over them all over the place." She stops. "You know, you only find what you are looking for, really, if the truth be known."