If you are expecting a feud full of venom, insults, fisticuffs, then you will be disappointed. If you are hoping for a more reasonable scientific dispute, with each side taking different academic viewpoints, then this is a story for you, figure 1. If you are hoping for a detailed history of human origins; I'm afraid this is not the Origins of Humans 101; I have had to be very selective. The story I'm going to tell involves, eventually, two opponents each vying for the notoriety, esteem, preeminence, that goes with being the first to establish beyond doubt the earliest true hominid; the family that includes Homo sapiens, i.e., us. Really, the only things that get bashed in this dispute are ego and pride. It has been portrayed, particularly since the 1970's by the press, as a battle between a "David" and "Goliath" with DR. Donald Johanson playing the role of David and the Leakey family, led by MR. Richard Leakey during the initial confrontation, playing the role of "Goliath". I emphasize that one had an academic background, a Doctorate, while the other was merely a Mr, a point not lost by the American TV and newspapers in particular in enlarging the disagreement and the story. The search for the earliest hominid has always involved controversy, disagreement and debate, but that between Richard Leakey and Donald Johanson received the most attention, and the combatants haven't spoken to each other since 1981.
The Leakey's were British and essentially they ruled the paleo-anthropological world for decades because of their remarkable finds of hominid fossils in East Africa, mainly in Tanzania and Kenya, which began with Louis Leakey in 1926. His rather brash and audacious approach earned him a number of nicknames in the press including the
"abominable showman".
Nevertheless, they were the establishment, sometimes stuffy and pretentious, but certainly the authority when it came to tracing the history of early hominids. After Louis Leakey's death in 1972, his son, Richard, became king of the mountain. But Louis's legacy continued, for sometime later a reviewer of one of Richard's books wrote in the Economist;
"Depending on which side of the Atlantic you come from, Mr. Leakey is either a possessive and obstinate ignoramus with talent for publicity, or the last great amateur scientist, who is right far more often than his better trained rivals in his guesses and interpretations of fossils."
Whereas it is true that Richard Leakey didn't have a degree, because he and his two brothers spent their formative years fossil-hunting with their parents, they had considerably more field experience than most academics achieve in an entire career.
Don Johanson, on the other hand, was often portrayed as a young, energetic lone-academic fighting against this self-appointed dynasty. But don't be fooled ... Johanson wasn't exactly an angel! ... although one colleague, Tim White of the University of California at Berkeley, does seem to have had an especially strong influence on him. In 1974 Don Johanson made a truly spectacular find in Ethiopia but according to at least one writer he was so obsessed with the Leakey's, especially Richard Leakey, who was just a year younger, than that at the time of the discovery:
"As he held aloft leg, arm and hand bones for the camera, he called out, 'Hey Richard, look at this one! This one's a good one! I've got you now Richard! I've got you now!"
A colleague of Johanson, Maurice Taieb, is also quoted as saying that after the discovery:
"Johanson begins to act as if he is the leader. He wants everything for himself, and it was all because he wanted to pass Richard."
So, this then, is the background to this scientific feud, the two young Turks of anthropology of those days locking horns while staunchly defending their own territory; prima donnas and egos ... pride and prejudice ... it was all on display in this feud.
Alan Walker, a colleague of Richard Leakey at Pennsylvania State University, once said that tracing the origin and evolution of modern man is like trying to complete a 3-dimensional jigsaw puzzle with no picture on the box and half the pieces missing! The only thing we can be certain of is that the discovery of the origins of modern man, Homo sapiens, is little more than 100 years old and it is a complicated story. So, rather than tell the whole story in true chronological detail, I will paint the picture as we see it in hindsight, so occasionally we will step aboard our time travel machine and flip between the present and the time the discoveries were made. The story is really an epic tale and involves many unlikely sets of circumstances. And as we will see it is littered with feuds and disagreements along the way. It is a story that takes us around the world, see figure 2 - from China, to Indonesia and East Africa, including Kenya, Tanzania and Ethiopia - and it is a story that is far from complete.
At the end of the 19th century there were essentially two main questions in human anthropology:
Undoubtedly, there was a large "hole" in the fossil record in the line of human descent. So, basically, the questions became, figure 3, what happened over the past 10 million years? ... was there some "missing link"? What did the earliest hominid look like? Where did they come from? To many, the discovery of the missing link, and the earliest hominid, was THE prize, some even suggested that after the pursuit of the Holy Grail, it was the second greatest prize of all time. Charles Darwin, in his book, The Descent of Man, published in 1871 had caused a minor sensation with his suggestion that early man came from Africa. Such an idea caused a great deal of concern amongst the public, particularly the white-supremicist Western Europeans, who now had to contend not only with the possibility that they were descended from apes but also from non-whites! The German zoologist Ernst Haeckel was a champion of Darwin's ideas on evolution and he recognized, like Darwin, that humans and apes have a common origin, linked by what he called "Human Apes". Haeckel reasoned that there must have been more than a single evolutionary step and he called the Intermediate form "Ape-like Man" or Pithecanthropus. He conjectured that the creature - the missing link - would have looked human in many ways and have had human like mental characteristics, but in 1876 he wrote, it:
"did not possess the real and chief characteristic of man, namely, the articulate human language of words"
He gave his creature the full name Pithecanthropus alalus; where Pithecanthropus is the genus, i.e., "Ape-like Man", and alalus is the species name, i.e., "silent". He conjectured that Pithecanthropus had arisen on Lemuria, a continent then thought to have sunk beneath the Indian Ocean ... before Wegener, one theory of the formation of continents was that vast regions of a southern continent had collapsed and sunk, filled with water to produce the Oceans. From Lemuria the evolutionary descendants migrated westwards into Africa, northwestward into Europe and the Middle East, northward to Asia and over the land bridge to the Americas, eastward via Java to Australasia and Polynesia! Bizarre as this appears to us, it was a perfectly reasonable assumption given the knowledge - or rather the lack of knowledge - of continent formation at the time!
Shortly afterwards, a young Dutch anatomist, Eugène Dubois made an interesting discovery. Dubois had developed a passion for finding the true human ancestor, that is the "missing link". After completing his medical studies in 1884, Dubois set out to find Pithecanthropus. Luckily for him, Indonesia was one of Holland's colonies and it was on the very edge of the supposed lost continent. So, leaving behind a career in academic anatomy at the University of Leiden, Dubois took advantage of the presence of the Dutch East India Army in Sumatra and managed to get a post as medical officer. He hoped that this position would give him the opportunity to seek out fossils. In 1889, two years after arriving in Java he convinced the military authorities to support his paleontological surveys full-time and they even supplied gangs of convicts to help with the work!
The first piece of the jigsaw puzzle was his discovery in 1891 of fossils - including a tooth and a skull cap - with some human like characteristics, see figure 4. He wasn't sure he'd discovered Haeckel's Pithecanthropus alalus, but after changing his mind several times - as you can see from his notes - he decided he had discovered Pithecanthropus erectus, because there was no doubt that this ape-like man had walked upright. Later, it was identified as Homo erectus, our modern description although it is still often referred to as Java man. At the time of Dubois' discovery, there were very few hominid fossils known; the famous discoveries in South and East Africa lay decades ahead. The only fossils known were those of Neanderthals, the first bones of which had come to light in a limestone quarry in the Neander Valley, near Dusseldorf, Germany. However, they were clearly a relatively modern type of hominid that had become extinct some 34,000 years ago. Dubois' find was much more interesting, much older and something much more primitive. Unfortunately, Dubois was unable to convince his peers, other than Haeckel, that he had found the "missing link". Scholars of the day
"praised"
him for his enterprising spirit and persistence but he could not get them to accept his finds as a transitional form between man and ape. Now, we know that this creature is some 700,000 years old and directly on the human line.
Gradually, however, Dubois' claim for Java Man gained credibility. There was a major sensation in 1912 with the discovery by Charles Dawson of parts of the jaw bone and cranium of so-called Piltdown Man near the south coast of England, see figure 5. This creature appeared to be large-brained, with a small jaw, which gave rise to the idea that an enlarging brain - interpreted by the public as increasing intelligence - was the major change between us and the apes. This was all very comforting.
In 1937 another Dutch anatomist Ralph von Koenigswald, encouraged by Dubois claim for Java man, also began excavating in Java and eventually amassed fossil fragments from some 40 Homo erectus individuals, see figure 6. Meanwhile, in China, in Zhoukoudian, near Peking (now Beijing), Davidson Black, a Canadian fossil hunter, discovered Peking man, see figure 7; in 1926 a tooth and then in 1929 a part of a skull. Without question, it was the same kind of creature as Dubois' missing link, i.e., Homo erectus, and now we know the skull fragment has an age of 420,000 years. Between 1929 and 1937 some 14 partial craniums, 11 lower jaws, many teeth, some skeletal bones and stone tools were discovered from the same site. Their estimated age is 300,000 to 500,000 years old.
The salient features of the Java and Peking specimens that allows one to recognize them from small fragments is the long, low cranium, containing a brain about 2/3 the size of modern brains and prominent ridges of bone above the eye sockets, as shown in figure 8. In his book Origins Reconsidered, written with Roger Lewin, Richard Leakey says:
"When I hold a Homo erectus cranium in my hand and look it full in the face, I get the strong feeling of being in the presence of something distinctly human. It is the first point in human history at which a real humanness impresses itself so forcefully."
Of course, this is now, or rather 1992, when the book was written. In our story we are still in the 1920's, when all the fossil evidence of human history had come from Europe - with Piltdown Man and Neanderthal - and from Asia - with Homo erectus, then known as Pithecanthropus erectus, - Africa was considered by most experts to have little to do with human evolution, so in February 1925, when Raymond Dart announced, in the highly esteemed scientific journal Nature, that he had found fossils in his adopted country of South Africa, of an apelike creature that was ancestral to humans, he was rudely scorned. His discovery, from debris sent to him from a limestone quarry at Tuang, on the southwest edge of the Transvaal, near the Kalahari Desert, was a fossilized skull of a young child, shown in figure 9, about the size of a grapefruit. He wrote later:
"I stood ... holding the brain as greedily as a miser hugs his gold. ... Here, I was certain, was one of the most significant finds ever made in the history of anthropology."
The finder of any new fossil had the privilege of choosing how to name it and locate it in the chronology. Dart called it Australopithecus africanus, "southern ape from Africa", figure 10, but the skull will always be remembered as the Tuang child. Literally overnight, the 32-year old Dart had become a celebrity. However, his find was not widely appreciated nor understood and so it was given a most unenthusiastic response. From the scientific community came mainly ridicule and resistance. One anthropologist simply dismissed the Tuang child as:
"just a somewhat beat-up chimpanzee."
As an interesting aside, the skull has holes on the top of it that only recently were given an explanation. Paleo-anthropologist Lee Berger reasons that about 2.5 million years ago the small child was grabbed by a bird of prey.
"The world was a cruel place for hominids,"
says Berger.
"They not only had to watch every bush they passed by, every rock they turned over, every tree they walked under, but now we know they also had to keep one eye on the sky."
Returning to our story, when he published his results Dart faced a number of problems.
Dart's A. africanus or Tuang child was not only the first, early hominid to be found in Africa, but the earliest hominid found anywhere; but it just didn't fit the ideas of the time. As a result it became the butt of jokes in cartoons and in the music hall's of the day. (But if we get into our time machine and jump ahead some 30 years in our story, Tuang child was recognized and heralded as a major find, when in 1953, Kenneth Oakley showed that Piltdown Man was a fake; the cranium was modern and the jaw was from an orangutan. Finding out who perpetrated the crime became a classic "who dunnit" rivaling any Sherlock Holmes mystery.) But returning to the late 1920's, Dart, understandably somewhat disillusioned by the negative reaction, resumed his search for hominid fossils with the Scottish paleontologist Robert Broom. Between the 1930's and 50's they unearthed many hominid fossils in South Africa, but ironically, nothing more from the Tuang quarry. Some were like Tuang child in which the lower jaw was large but not enormous, in others the mixture of ape- and human-like features was associated with a huge jaw and large cheeks, these latter specimens were later called Australopithecus robustus. So, here were two types of bipedal ape-like creatures, the principal difference being the size of the lower jaw; although difficult to date at the time it was believed that africanus predated and was ancestral to robustus, Homo erectus and Homo sapiens. So, the human line was then thought to be simply Y-shaped; a single ancestral species africanus splitting into two lines, robustus and Homo, as shown in figure 11.
It was into this mélange that the quite remarkable Leakey family made their entrance, figure 12. Louis Seymour Bazett Leakey was born on August 7, 1903 at the Kabete Mission, 9 miles from Nairobi, Kenya. He was the son of Harry and Mary Leakey, English missionaries to the Kikuyu tribe, and despite brief stays in England, Louis grew up more African than English. He played with Africans, learned to hunt, spoke fluent Kikuyu and was initiated as a member of the Kikuyu tribe. At age 13, after discovering a stone tool, he knew he wanted to be an archeologist. In 1922 he started studies at Cambridge but an accident playing rugby a year later interrupted his studies and he left to participate in a dinosaur-hunting expedition in what is now Tanzania. After, he earned money to continue his schooling by giving lectures about the expedition. The expedition proved an introduction to his later career for he argued not only that Darwin had been right about Africa being the location for the origin of humans but that he, Louis Leakey, was going to prove it! As one author, Hal Hellman, wrote recently:
"Tall, handsome, and confident, he delighted in goading the academic world as he became better known."
He returned to Cambridge in 1925 and graduated brilliantly in anthropology and archaeology in 1926. During his years at Cambridge he was recognized as egotistical and stubborn - even "pig-headed" - but he did make friends easily.
By the time he graduated he had also formed the view that human ancestors were much older than the half-a-million or so years that was commonly held at that time. Also, he had little time for armchair academics and so in 1926, at age 23, the audacious Louis Leakey began his search for hominid fossils. He chose to search the Great Rift Valley in East Africa, shown in figure 13, which runs north-south through Ethiopia, Kenya and Tanzania. At the time few thought it an area of any interest but today, we recognize it as the location of the world's richest hominid sites; the very cradle of the human race (although there are still some dissenters who favor Asia).
The region displays unusual geological character because of plate tectonics, the subject we looked at last week. Two plates come together in the region so it is an area where the constant drifting over time has produced a large fault line in the African Plate. There are not only volcanoes and depressions in the Great Rift Valley, some of which have become lakes and rivers, but the movement has thrust upward and exposed the very old sedimentary layers that contain fossil evidence of the past.
Louis selected Olduvai Gorge, a 30-mile long gash in the Serengeti Plain in Tanzania. In places the fossil deposits rise some 300 feet above the sandy bottom. It's dry, hot and forbidding; Richard Leakey, who spent a good deal of time there as a young boy with his parents, said:
"I remember quite clearly why I never wanted to be a paleo-anthropologist. ... You were always hot, sticky, wishing for shade and swatting at flies."
And this was at least something that he and Don Johanson could agree on, for Johanson later added:
"I almost always came back with some kind of illness. I had very severe fevers in the 1970's that were never diagnosed."
Imagine, then, the long hours of searching under the blazing Sun, the problems of bringing in sufficient water and food, the difficulty of searching the sand and stones for tiny fragments of fossils and then recording precisely the location and depth of all finds. But Louis had a "nose" for knowing where to search although he was not the most careful of technicians and this did cause serious problems for him and his reputation, later in 1934-5, when he was unable to relocate certain sites where he'd made some important finds. But, clearly, he was a rising star in paleo-anthropology and in 1930 he was awarded a Ph.D. However, to put it politely, as far as the ladies were concerned, Louis was a bit of a philanderer ... in 1936 in a fragrant disregard of the social norms of the time he divorced his first wife, Frida, whom he married in 1928, and with whom he'd had two children. Within a year he married Mary Douglas Nicol, a scientific illustrator he'd met in England in 1932, and she joined him in his work. His wayward behavior didn't go unnoticed and it simply further depressed his reputation as far as his peers were concerned. However, Mary learned paleo-anthropology from Louis and together they discovered fossils in Kenya of ape-like animals that lived between 14 and 20 million years ago. In contrast to Louis's charming, gregarious, outgoing nature, Mary was shy, reserved and not very sociable, and in her own words, "not very fond of other people". However, some years later, it was said that she enjoyed a good Cuban cigar and a good Scotch whiskey! Louis was often impulsive and cavalier with his discoveries and claims; Mary preferred to sift carefully through scientific evidence before reaching conclusions. But, together, they worked well.
The scientific community at large were still unconvinced about the information coming from Africa, but that changed at a scientific conference held in 1947. When Robert Broom showed that the Australopithecines that had been discovered, including Dart's Tuang child, dating to between 1 and 2 million years old, did lie in the human line, the experts finally agreed with Louis that Africa was indeed the "cradle of mankind", as Darwin had predicted. Louis's scientific reputation and credibility, at least, were restored.
Eventually, one July morning in 1959, after some 30 years of stubborn, persistent searching they made a big discovery, or at least Mary did, as Louis lay ill in his tent with a fever. She unearthed a piece of skull and two huge teeth. She ran back to camp shouting:
"I've got him! I've got him!"
Ironically, it was 100 years after the publication of Darwin's On the Origin of Species. With dental tools and fine brushes they unearthed more than 400 fragments of bone that permitted the reconstruction of an adult skull, figure 14, and they also found tools along with it. Louis coined a new name; Zinjanthropus boisei, the genus name meant East African Man and the species name honored Charles Boise who had funded their research. However, the Leakey's generally referred to the creature as "Zinj" or as "Dear Boy". Zinj had the same brain capacity as Australopithecus robustus but in all other aspects he was hyper-robust. Dated at 1.8 million years Zinj was a contemporary of, and today is believed to be a close relative of robustus, Zinj now bears the name Australopithecus boisei. Like robustus, boisei is believed today to be a dead-end branch of the hominid tree. Dead end though it may be, it certainly led to substantial interest, fame and support for the Leakey's; the worldwide fame meant they had become a household name. They became better funded, better equipped, better supplied and could support more staff. Their increased endeavors would lead eventually to the important discovery of one of the earliest members of our own genus Homo.
While excavating in Kenya, Mary and Louis would take their sons along with them. That proved to be fortuitous because in 1960, shortly after the discovery of Zinj, the Leakey's eldest son, Jonathan, found fragments of a new species at Olduvai - affectionately referred to as "Jonny's child" - with an estimated age of 1.8 million years. During the next three years Mary, Louis and their helpers unearthed numerous fragments of what they believed was the same species as Jonny's child, including foot and hand bones - very rare treasures, indeed. Although similar to Australopithecus in many ways, the new creature had a much less pronounced projecting face, smaller teeth and a much larger brain, see figure 15. Later, in April 1964 it was confirmed as a separate species and Louis Leakey named it Homo habilis, meaning skillful or handy human being. At the time it was thought that it was almost certainly on the human line, see figure 16, between Australopithecus africanus and Homo erectus although the suggestion was certainly not shared by all paleo-anthropologists; and even Louis, and later Richard Leakey, had doubts that the human "tree" would turn out to be that simple; they both favored a more "bush-like" structure, with many, as yet undiscovered, branches. So, let us turn our attention to Richard Leakey.
Richard Erskine Frere Leakey, figure 17, was born in Nairobi, on December 19, 1944. Born on-site, so to speak, he would accompany his parents on their excavations. But, as he was growing up, he had no intention of following in their footsteps, as I mentioned earlier. Independent like his father, he also had no desire to bask in his parents' fame. However, he was passionate naturalist and he started his own safari company. But when, in 1963, he found an Australopithecine jaw while exploring the Lake Natron region of Tanzania, he decided to become an anthropologist after all. He completed a two-year secondary education program in London in six months, but running out of money and of interest in sitting in classrooms, he returned to Kenya without a university degree.
In 1967 he joined an expedition to the Omo River valley in Ethiopia. It was during this journey that he became interested in Koobi Fora, along the shores of Lake Rudolph (now Lake Turkana) in Kenya. Although well north of Olduvai it was still part of the Great Rift Valley. There, over the next decade or so, Richard Leakey and his fellow workers uncovered some 400 hominid fossils, representing perhaps, 230 individuals. Koobi Fora has proved to be the site of the richest and most varied assemblage of early hominid remains found anywhere in the world to date. In 1968, he became administrative Director of the Museums of Kenya; a position he was to hold until 1989. In 1971 he married Maeve Gillian Epps - a British born zoologist - who had been hired originally by Louis Leakey in 1965 to study monkeys and apes in Kenya, like Diane Fossey and Jane Goodall before her. Later, she joined Richard Leakey's fossil hunting team. After his father's death in 1972 Richard set up the Louis Leakey Memorial Institute for African Prehistory, a fossil repository and postgraduate study center and laboratory.
The 1970's proved to be the watershed in our story; a great number of significant discoveries of hominid fossils were made that had to be integrated into a consistent line of descent; and that was the problem!
In August 1972, three months before Louis died, Richard Leakey made a major find; an almost complete, magnificent skull, see figure 18, eventually dated at 1.9 million years old. He was reluctant to categorize the fossil, referred to as "1470", as anything other than a Homo species; he was not yet ready to identify it as Homo habilis as many encouraged him to do. The reason is that paleo-anthropologists are confronted with many problems when trying to identify and classify a "new" fossil and they have learnt to be cautious. One problem is the occasionally large variability of characteristics between the same species from different sites and different ages. A second problem is sexual dimorphism, see figure 19; are the females of the species different from the males, for example, in height or other physical characteristics as shown here between two Australopithecus boisei specimens? What about the two shown in figure 20? They still await final identification! Eventually 1470, at 1.9 million years old, was identified as the oldest known example of Homo habilis.
Although Richard Leakey was clearly a member of the Leakey Hominid Gang and had inherited some of the Leakey luck, he was, nevertheless, his own man. For instance, in contrast to his parents who appeared to become affectionately connected to their fossil finds - remember Zinj, which they often called Dear Boy or Nutcracker Man? - Richard always referred to his fossils by their field designation number. He hoped that by referring to them in that way any future discussions, and the almost inevitable disagreements, could be carried out at a less emotional level.
Later, in 1992 in Origins Reconsidered Richard Leakey wrote that 1470 was:
"a fossil that did for me what Zinj had done for Louis; it made me famous, put me on the international stage."
In subsequent expeditions in the 1970's Richard Leakey was also very successful in making significant finds. The finds included a 1.7 million year old example of Australopithecus boisei with a complete and intact cranium lacking only teeth, see figure 21, and a superb Homo erectus skull, found by Bernard Ngeneo, shown in figure 22. The significance of these two finds is that that the fossils are of the same age, about 1.7-1.8 million years, proving that the two species, Australopithecus boisei and Homo erectusexisted in the same place at the same time. So, in the space of about 4 years Richard Leakey, selecting his own site Koobi Fora on Lake Turkana, Kenya, had come up with as many finds as his mother and father had achieved in 30 years of grueling effort.
By 1979, at age 35 years. Richard Leakey - an amateur - had become an international superstar. He even outshone his mother who, in 1978, discovered one of the greatest paleontological treasures ever found; crisp, fossilized footprints of two or three Australopithecines who had walked side-by-side in a northerly direction about 3.6 to 3.7 million years ago, see figure 23. The 75 foot long trail was found at Laetoli, some 20 miles southwest of Olduvai and demonstrated in spectacular fashion that these early creatures walked upright. From the length of the strides it was determined that one of them was about 4 feet 7 inches tall and the other was 3 feet 11 inches tall; since our early ancestors were thought to be sexually dimorphic, the former may have been made by a male and the latter may have been a female. The tracks are so close that if the creatures were side-by-side they were almost certainly in contact with each other, possibly holding hands. Or one may have been following closely behind the other. The footprints had been impressed in newly fallen volcanic ash, debris from a nearby volcano, Sadiman, that had been gently erupting at the time.
However, to return to our main story, being a member of the Leakey Hominid Gang also had its down-side for Richard. His discoveries and leading role in African paleo-anthropology often caused envy and resentment because of his "amateur" status; remember he had not received a university degree. But Richard, like Louis, was a good publicist, not just for himself but for the whole paleo-anthropological community. Of course, being a good publicist was essential if one wanted to raise money for expeditions!
Then, in the Fall of 1974, Dr. Donald Carl Johanson and his team came across almost 40% of a skeleton dated at over 3 million years old, see figure 24, while digging in Hadar, a remote desert area of Ethiopia. This creature, thought to be female, about 3 feet 6 inches tall was strikingly human-like; nicknamed "Lucy", she shot Don Johanson to the very peak of human paleo-anthropology much more rapidly than even Richard Leakey had managed.
Donald Johanson, figure 25, was born in Chicago in 1943, the son of Swedish immigrants. His father died when he was 2 years old and he moved with his mother to Hartford, Connecticut. He developed an interest in anthropology at a young age, mainly from a neighbor who taught the subject. However, initially, he majored in chemistry at University but later switched to anthropology and worked during summers on archeological digs. He recalled later:
"I was still in high school when I read about Zinj in the National Geographic. The name Olduvai, with its hollow, exotic sound, rang in my head like a struck gong. I was about to graduate, and despite what my mentor ... had been telling me about the virtues of chemistry as a profession, I began thinking more and more about anthropology. Leakey's experience was proof that a man could make a career out of digging up fossils."
He added:
"I went off to college and Leakey promptly jolted me again. In 1962 there came a report that he had found another hominid fossil at Olduvai, this time not an Australopithecine but a true human [H. habilis ]."
He said the real surprise to him was:
"the age of this new Homo; about 1.75 million years, the same age as Zinj. At one stroke Leakey and his associates had tripled the known age of humans."
One can sense, in these words, that Johanson was excited by the missing link even then. He transferred to Chicago to study with F. Clark Howell for his graduate work, and carried out a comprehensive study of chimpanzee dentition for his doctoral thesis.
In 1970, while he was beginning work on his doctoral dissertation, events took an ironic turn. A geology student from France named Maurice Taieb, who was an acquaintance of Richard Leakey's, had been putting together the geological history of the remote deserts of Ethiopia. He was particularly interested in a region known as the Afar triangle, at the northern end of the Great Rift Valley, figure 26. Taieb later explained:
"People were just beginning to understand the plate tectonics theory and so I thought I would study this area for my dissertation."
After seeing some of Taieb's early specimens from the region, Richard Leakey suggested that he take along a paleo-anthropologist on his future field trips., and believe it or not, Leakey recommended Johanson! Johanson had not yet completed his dissertation and although others advised him he'd be wasting his time, he decided to go. He made trips to Ethiopia in 1970 and 1971 and in 1972 he made a short exploratory visit to Hadar in the Afar region. Johanson was so impressed by what he found that he and his colleague planned a much larger scale expedition. Johanson completed his Ph.D and took on a teaching position at Case Western Reserve University. Shortly before his death, Louis Leakey provided Taieb and Johanson with letters of support that helped them get the necessary funding to get to Hadar. A member of the group, Jon Kalb recalled later:
"Johanson wanted to monopolize the expedition to make the search for hominids its only purpose."
When, on a visit to the site at Hadar, Richard Leakey asked Donald Johanson whether he expected to find hominids there, the latter replied:
"Older than yours. I'll bet you as bottle of wine on that."
"Done,"
said Richard.
As I mentioned just now, in 1974 Don Johanson and his group struck "gold" when they unearthed "Lucy" - named after the Beatles song "Lucy in the Sky with Diamonds" which the group members played over and over on the night of the discovery amid much drinking and dancing! Lucy, shown in figure 24, about 3 feet 6 inches tall and an adult female about 25 years old, was dated at 3.2 million years.
Johanson knew full well what the term the oldest human meant, it had a sort of magical ring to it, and that's what he claimed for Lucy. In 1975 he and his group found the fossilized remains of at least 13 other individuals in the same Hadar area, which he referred to as the First family. Again, in 1976 they found more hominid fossils and tools dated at over 3 million years. However, political problems in Ethiopia in 1976 ended further expeditions for some 15 years.
Meanwhile, in 1974 Johanson had become curator of the Cleveland Museum of Natural History, and now he tackled the problem of characterizing his finds, with a recent Ph.D graduate Tim White. What precipitated the dispute between Leakey and Johanson was the interpretation of where "Lucy" fit into the picture of human origins. Initially, Johanson was of the opinion that the Hadar fossils were a mixture of three different Homo and Australopithecine species; indeed, he and Taieb announced that in an article in the March 1976 issue of Nature. But Tim White, an anthropologist from Berkeley, eventually convinced Johanson that Lucy and all the finds belonged to a new species, which they named Australopithecus afarensis. Furthermore, they maintained that Lucy's pelvis and leg bones showed that she was bipedal with a rolling gait, perhaps like a modern gorilla, see figure 27. Also, the species exhibited sexual dimorphism; the females - like Lucy - were substantially smaller than the males.
At a press conference to announce their findings of Lucy - the oldest "human" - and the first family, Johanson's team claimed that they had made:
"an unparalleled breakthrough in the search for the origins of man's evolution. ... We have in the matter of merely two days extended our knowledge of the genus Homo by nearly 1.5 million years."
Introducing a new species like this is a big event. In this case, Johanson created a major storm in two ways. First, when the official announcement was made in 1978, Johanson announced that a number of Mary Leakey's finds, including the Laetoli footprints, should be included in his new species. Second, in an article in the January 1979 issue of Science, Don Johanson and Tim White swept aside all the current ideas of human evolution that the Leakey's had proposed and in turn substituted their own. They set up Lucy and the first family as the earliest group that could be thought of as true human ancestors. So here was Don Johanson, turning the whole field upside down. When reviewing Johanson's and White's suggestions, the Times in London reported that:
"All previous theories of the lineage which leads to modern man must now be totally revised."
The tree proposed by Johanson, shown in figure 28, had Australopithecus afarensis as the trunk with basically two branches; with one leading towards A. africanus, A. boisei and A. robustus, all of which had become extinct and a second branch that led through Homo habilis to H. sapiens. As far as Richard Leakey was concerned, there were a number of significant errors: it was still Y-shaped and much too simple. Further, Johanson had proposed that the split between the two main hominid lines, Australopithecus and Homo, occurred after Lucy and the first family, sometime around 3 million years ago, and it contradicted Leakey's belief that the human line began much earlier, between 5 and 7 million years ago. And finally, Johanson claimed the title to being finder of THE missing link; Richard Leakey argued that she was not the missing link, she was merely another, albeit an early, Australopithecine. In a letter to Science shortly after Johanson's announcement, Richard Leakey and his colleague Alan Walker said that there was simply not enough fossil evidence to support Johanson's claim and that in their view it was highly likely there was more than a single species existing when Lucy lived. Privately, Leakey must have thought that in his eagerness to claim the title, Johanson had been far too premature. Also, one legitimate argument against Johanson's insistence that Mary Leakey's finds be lumped in with his, is that they are separated not only by half-a-million years in time but by a thousand miles in distance. In a letter to a colleague, Mary described Johanson's work as ...
"slovenly".
Things grew steadily worse when Johanson published his book Lucy: The beginnings of Humankind in 1981. In commenting about Mary Leakey's reaction he wrote:
"She hit us ... with a hair splitting obfuscation about nomenclature, about errors she claimed we had made in naming our new species."
Nevertheless, the Leakey's and Johanson were still on speaking terms. However, that was about to end after Walter Cronkite invited Don Johanson and Richard Leakey to appear on his popular television program, Universe, and discuss the recent discoveries in public. According to Johanson, Leakey was claiming that any rivalry between them was a myth and the invention of the press.
"I thought that was misleading,"
said Johanson,
"and I welcomed the opportunity to meet with Richard on the record."
On the other hand, Richard Leakey believes he fell into a trap for he had been assured the program was going to be a discussion about creationism and human evolution. It wasn't that Richard Leakey feared a debate but he felt that he would be at a disadvantage because the only fossils under discussion were Johanson's. Sure enough, Johanson brought some props with him on the program, including an Australopithecus afarensis skull. Johanson said that:
"As soon as the cameras began to roll, it became apparent that a debate was what Cronkite was looking for."
Johanson presented his version of the tree of human lineage on a diagram and looked for comments from Leakey. Richard Leakey, thinking he had been deceived, was angry and drew a big X across the picture. He maintained that there simply wasn't enough corroborating fossil evidence and added a big question mark. Later Leakey described the whole incident as
"unfortunate"
although Johanson insisted
"I won".
That was in 1981 and they haven't spoken since. So, what's happened to Leakey and Johanson since?
Well, in 1969 Richard Leakey had been diagnosed with a terminal kidney disease that grew progressively worse until he received a transplant from his younger brother Phillip in 1979 and made a remarkable recovery. In the early 1980's he began devoting more of his time to Kenya's museum system although his fossil hunting continued. In 1984 his team found the most impressive fossil of his (or, arguably, for that matter anyone else's) career. Nicknamed "Turkana Boy", and shown in figure 29, it is the nearly complete skeleton of a Homo erectus boy aged around 10 years old, whose skull was essentially identical to Java Man found by Dubois almost a century earlier on a different continent but some 900,000 years younger, see figure 30. However, Richard Leakey has kept away from meetings and conferences that in earlier days he had reveled in. In 1989 Daniel arap Moi, the President of Kenya, appointed him the Head of what is now the Kenya Wildlife Service. He raised hundreds of millions of dollars and revamped Kenya's approach to wildlife conservation; he armed anti-poaching units and instituted a heavily criticized but effective rule permitting the shooting of poachers of elephant and rhino on sight. In 1993, a crash caused by a malfunction in the airplane he was flying - whether by sabotage or a simple accident, it's not clear - resulted in the loss of both legs below the knee. He resigned from the Wildlife Service in 1994 amid politically motivated accusations of corruption, racism and mismanagement; but was reinstated by arap Moi in 1998. Resilient as ever and now bearing artificial limbs, he founded an opposition political party in Kenya, called Safina, after which he suffered public humiliation including beatings. However, in December 1997 he was elected to a seat in the Kenyan parliament. Richard's wife, Maeve, continues to work in paleo-anthropology and has made a number of significant finds pushing the hominid line back even further. But it doesn't end there; their daughter Louise graduated in 1995 with an honors degree in geology and zoology and has begun managing her own paleontological digs.
And what of Don Johanson? In 1981 he founded the Institute of Human Origins at Berkeley, a non-profit institution devoted to the study of prehistory. In 1987 the IHO began conducting expeditions to Olduvai Gorge and made important finds. In 1990 they recommenced excavations in Ethiopia. In 1997, the IHO moved from Berkeley to Arizona and became affiliated with Arizona State University.
So where are we today in our search? Well, the recent advances in genetic techniques have offered the possibility of an alternative approach for identifying and classifying species. Some molecular genetic studies have suggested that the splitting of the ape and human line took place some 5 million years ago, possibly as much as 7 million years ago, more in line with Richard Leakey's idea. However, the fossil evidence is lacking.
More recent fossil evidence has appeared that indicates that the simple tree that Johanson proposed is not correct. For example Maeve Leakey, Richard's wife, while digging at Kanapoi, Kenya, another region of the Great Rift Valley, in 1994 unearthed some fossils of an Australopithecine species that was bipedal and date back to about 4.1 million years ago. Also, a former colleague of Johanson's, Tim White and his team uncovered fossils at another site in Ethiopia from some 17 individual hominids dating back 4.4 million years. They were from a species that appeared different from Maeve Leakey's finds ... so it appears that more than one species co-existed some 4+ million years ago.
Further doubts on Johanson's classification of the Laetoli footprints as coming from the same species as Lucy have been raised by Russell Tuttle, an expert on comparative anatomy at the University of Chicago. He argues that A. afarensis toes were too long and curved to make those human like footprints.
To confuse matters even further Peter Schmid and Martin Hausler, Swiss anthropologists at the University of Zurich, are not convinced that Lucy is female! Based on reconstructions of Lucy's pelvis they claim that it has more male traits than female characteristics. Furthermore, they claim that Lucy's pelvis is too small to have given birth to an Australopithecine infant.
"The only reason you would say Lucy is a female is her small size,"
says Hausler.
"Perhaps we should change her name to Lucifer."
Johanson will have none of it. Believing that A. afarensis was sexually dimorphic, he says:
"If Lucy is a male, imagine how small that would have made the female of her species."
The recent addition of a dozen or so more Australopithecine species, see figure 31, and and a dozen or so more Homo species, see figure 32, has made the picture very much more complicated! What does all this do to the human line? One of the more simple trees of human phylogeny that takes into account the more recent finds, has been proposed by Phillip Tobias of the University of the Witwatersraand in Johannesburg, South Africa, and shown in figure 33. He puts the break between humans and apes over 5 million years ago with Lucy, that is A. afarensis, out of the direct Homo line. Furthermore, he identifies the Laetoli footprints as early A. africanus. Right or wrong, one thing is now certain; the human line is not a simple Y shape; it looks more like the "bush" with lots of "twigs" as the Leakey's have always maintained.
Although he has mellowed a bit Donald Johanson remains involved in the field and still maintains he's essentially correct. In a recent article he wrote:
"She [Lucy] may not be our oldest ancestor, but she remains the best known."
Richard Leakey makes no comment leaving others to carry on the fight.
So, what is the line that leads to humans? One thing is clear; paleo-anthropologists will continue to argue the details about the basic nature of our ancestors. For me, when I read newspapers or watch TV and see the incredible inhumanity that daily we inflict on each other, it wonder whether in some ways we are still walking the road to becoming human.
Louis Leakey once wrote:
"The past is the key to our future."
I suspect that he, like others referring to the past, is hoping that on looking back we learn more about how to handle the future; an optimistic view, if you like. However, I wonder whether that's true. Let me play devil's advocate for a moment and give you something to think about. Do we ever learn from the past? ... if so, why do we continue to have the sort of confrontations that we've seen in Ireland, the Middle East, the former Yugoslavia and Soviet Republics? And, what about these feuds I've talked about, didn't Bishop Wilberforce, who confronted Thomas Henry Huxley in the classic evolution debate, learn anything from Church's battles with the Galileo? ... what about Lord Kelvin, in denying radioactivity ... didn't he learn anything from Hobbes who had tried to ignore algebra? ... and finally Johanson and Leakey ... did they, like Newton and Leibniz, allow their egos and pride to rule their heads? Didn't these people learn anything? Oh, well.
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