Out of Africa: Discovering Our Shared Human Family, From Toumai to Turkana Boy

As the young museum attendant diligently unlocked the door I was full of excitement. I was about to meet a superstar—albeit one who had been dead for millions of years. With great reverence and awe I gently stroked her hand with the tip of a finger and felt as though I had made contact with a long-lost relative. This was Lucy, or Dinkenesh, as she is known in Ethiopia—part of the lineage that eventually led to us: Homo sapiens sapiens, Latin for “wise and thinking man.”

Africa is where it all began for us modern humans. We should be united by our shared beginning in a way that enables us to look beyond race, to a time when such differences did not exist. When one examines the long history of humankind, it becomes apparent that racial differentiation is a relatively recent occurrence; genetics present us with facts that are at odds with the cultural construct of racism. There may be new genetic interpretations in the future, but current thinking indicates that characteristics of the “white race” emerged between 8,000 and 12,000 years ago, well after many genetic divisions in Africa itself. Unfortunately, as the late Kenyan palaeoanthropologist Dr. Richard Leakey described, some are still reluctant “to embrace fully the idea that humans, whether blue-eyed Europeans or pale-skinned Asians, originated in Africa.”

Dr. Leakey and his equally illustrious parents, Louis and Mary Leakey, were making ground-breaking fossil discoveries at a time in the twentieth century when there was still ongoing research in the field aimed at disproving the theory that we all came out of Africa and were thus originally black. The discovery of a complete ancient skull in China in 1929, dubbed “Peking Man,” for example, led the Beijing authorities to fund research by Chinese palaeontologists aimed at showing that Homo sapiens first evolved in Asia, or that Peking Man was an ancestor of modern East Asian people. Such efforts persisted into the twenty-first century.

That we are all part of the original African diaspora is no longer disputed scientifically. New paleontological discoveries are still being made and the vast majority of the pieces in this fragmented and ever-developing jigsaw puzzle are missing, but even if there is still debate about precisely where it happened within the continent, Africa is certainly where the human story began. We are an African animal, an African species who colonized the world, at different times and in different ways. No human being on earth can deny that Africa is their first home.

About 2 to 3 million years ago there was a big freeze that killed the majority of animal life on land and sea. Africa was the region least affected by the Ice Age and life continued to flourish there. As wet, warm grasslands spread across the continent, these habitats created the perfect conditions for the evolution of the great apes: gorillas, chimpanzees and later the hominins or hominids (creatures between ape and human), from which we modern humans finally appeared. These primates gingerly came down from the trees to inhabit the ground and placed their safety in their wits rather than their strength.

It was the Victorian biologist Charles Darwin who first made the observation, in his 1871 book The Descent of Man, that since the African gorilla and chimpanzee are most like us in terms of their anatomy, and because they only existed in Africa, then humans must have originated there. Although Darwin’s reasoning may not meet today’s scientific standards, he had advanced a ground-breaking theory that creationists and many religious conservatives found abhorrent.

Gorillas are now only found in a few places in Africa, mainly in the Great Lakes region. More than a third of the 1,000 surviving mountain gorillas live under protection in the wild forests of the Virunga National Park. The mountains, a chain of volcanoes, span parts of Rwanda, the Democratic Republic of the Congo (DRC) and Uganda. I set off to see these endangered creatures in northern Rwanda, a mission that involved a long hike starting at dawn, through masses of thick vegetation glistening with morning dew.

My exertions paid off when I eventually spotted the gorillas through the foliage. A couple of adult gorillas, including one majestic silverback, lay indolently on the ground—seemingly reveling in the early morning sunshine, while a pair of young gorillas tumbled down from a mound and played together on the muddy earth. It was remarkable to see how similar they are to humans. They live in family groups and their movements, antics and expressions are so like ours. In fact, data shows that humans and gorillas differ in only 1.75 per cent of their DNA, far less than previously assumed. (Chimpanzees—our closest relatives—differ only 1.37 per cent from our genomes.)

Once Charles Darwin had advanced his theory that humans originated in Africa, other scientists began to try to piece together the evolutionary chain from gorillas and chimpanzees to humans by studying extinct species of hominins and looking at bipedalism in particular. Bipedalism, which occurred about 6 million years ago, meant a primate’s hands could remain free. About 3 million years later, this led to hominins being able to use their intelligence to make tools or hunt with weapons, assisted by their ability to rotate the wrist, a feature unique to apes and humans. Habitual bipedalism, the ability to walk permanently on two legs, is a defining characteristic of what makes us human.

One theory, propounded by early twentieth-century experts such as the Australian palaeoanthropologist Raymond Dart, posits that walking on two legs developed because, as the climate changed, there was less woodland and more grassland, making bipedalism a more efficient way of moving around. There was a long intermediate stage, during which bipedal hominins still had a divergent big toe for climbing up trees to escape predators on the ground and could swing from branch to branch with their rotating wrists.

Once hominins became upright around 4.4 million years ago, anatomical changes to the hands, shoulders, elbows, pelvis and spine took place. As the evolutionary chain developed, they began to look more like humans today.

Toumai, 7 million years ago
Scientists wanted to establish the date at which our human line diverged from other primates, and the breakthrough came in 2001. After a decade of digging through the sand dunes in the Sahara of northern Chad, a Franco-Chadian team of palaeontologists were rewarded for their efforts. They found fossilized bones, a partial skull and a mandible, ascribed to an ape-man who they dubbed Toumai, meaning “hope of life” in the local Daza language. Some experts believe Toumai, known as Sahelanthropus tchadensis, was from a species of primate that was a common ancestor to both humans and chimpanzees. Molecular evidence suggests that Toumai lived close to the gorilla/chimpanzee–human divergence approximately 7 million years ago, but it is not known if he or she was at times bipedal. This was nevertheless the point at which the evolutionary process that made us fully upright began.

Lucy or Dinkenesh, 3.2 million years ago
Let us fast forward another 4 million years to one of the most iconic discoveries: Lucy, a celebrity in the world of palaeontology. She was a member of a species known as Australopithecus afarensis, and was named after the Beatles song “Lucy in the Sky with Diamonds,” which was playing on the camp radio when she was discovered in Harar in eastern Ethiopia in 1974. Lucy is known as Dinkenesh in Ethiopia, meaning “you are marvelous” in the Amharic language, and it is how I refer to her.

There is a model of what Dinkenesh would have looked like at the National Museum of Ethiopia in the capital Addis Ababa. The real skeleton of Dinkenesh is under lock and key in a climatically controlled room, where the temperature is maintained at an optimum level for the preservation of her remains. An impressive 40 per cent of her skeleton was found, and its constituent parts are kept in carefully identified and classified pieces placed in special padded drawers. It was wonderful to see and touch Dinkenesh’s bones under the supervision of Professor Yohannes Haile-Selassie, a leading Ethiopian palaeontologist. He described her as “the icon of palaeoanthropology,” adding that experts like him are still learning a lot from her.

Yohannes proceeded to tell me how Dinkenesh lived 3.2 million years ago. A reconstruction of her head shows that its lower half points forward, unlike the flat faces of modern humans, and that her brain was no bigger than that of an ape. Her jaw was relatively small but her teeth were large. An adult, she stood about a meter tall and weighed just under 30kg. She regularly walked on two legs, freeing up her arms, which were relatively longer than ours. Dinkenesh would have used her hands to make simple tools like sharpened twigs in order to fish, dig out termites or kill small animals. Fossilized turtle and crocodile eggs were found near where she died, and support the theory that she foraged for food, possibly by raiding reptile nests. Still, Dinkenesh would mainly have enjoyed a plant- and fruit-based diet.

Dinkenesh probably slept in trees for safety. One theory holds that she may have died by falling from a tree—ironically, peril lay in her refuge. Despite her superstar status in hominin history, modern humans are not direct descendants of Dinkenesh. But she is still part of the lineage that eventually led to us.

Taung Child, 2.8 million years ago
The first evidence of a “hominin” was discovered much earlier. Professor Raymond Dart found the Taung Child in a limestone formation at Taung near Kimberley, in South Africa’s Northern Cape province in 1924. Taung Child lived about 2.8 million years ago and is from a species of hominins called Australopithecus africanus. I went along to the University of the Witwatersrand in Johannesburg, where he is kept. The prominent South African palaeoanthropologist Professor Francis Thackeray pointed out the braincase of the skull and the front of the face and lower jaw, and explained that for decades it was thought that our hominin ancestors were voracious predators, or “killer apes.” Some nearby eggshells were accordingly interpreted as the child’s lunch, but showing me the cracks in the Taung Child’s skull and eye-sockets, he told me that in the 1990s scientists like him began to notice that the damage looked similar to that of modern monkeys killed by eagles.

It seems that the Taung Child was not at home in his cave, but in the lair of a huge bird of prey, probably an ancient eagle, which killed him and dragged him there. It is a window into a time when our forebears were both predator and prey. Taung Child was the first hominin to be found in Africa, and he appeared much more archaic than other remains found elsewhere at the time. He provided the first hint that Charles Darwin may have been correct about humans originating in Africa.

Mrs. Ples, 2.5 million years ago
Some 20 years after the discovery of the Taung Child, South African palaeontologists Robert Broom and John T. Robinson uncovered a pre-human skull in the caves of Sterkfontein, north of Johannesburg, in 1947. She was called Mrs. Ples as a snappier alternative to the initial scientific name, Plesianthropus transvaalensis. After 2 million years of peaceful entombment, Mrs. Ples’s head was blown up by the dynamite of a lime mining operation. Scientists have pieced it back together, and it is now almost complete. Mrs. Ples, like Dinkenesh, had a small brain, similar in size to those of chimpanzees, and about a third of ours, but she walked on two legs. She was a significant find; her skull proved for the first time that walking upright had evolved well before any significant growth in brain size. Experts can gauge whether a hominin walked on two legs from a hole at the back of the skull called the “foramen magnum” through which the vertebrae and spinal cord enter. Mrs. Ples had such a hole and it pointed downwards, indicating she had been bipedal.

Different kinds of hominins co-existed in Africa and scientists are constantly trying to work out how various types such as the Taung Child, Mrs. Ples and Dinkenesh are related, but what we do know is that as various lines died out, just one, the “Homo genus,” led directly to us modern humans. This is where the detective work shifts eastwards on the continent.

Zinj, 1.75 million years ago
The East African Rift Valley, a huge split in the earth’s crust that spans Tanzania, Kenya and Ethiopia, is rich in the remains of hominins impeccably preserved in its soil and rock. As I went down the Olduvai Gorge in northern Tanzania and picked my way through the dust and rocks, I gazed at the layers of sediment, made up of clay, sandstone and conglomerates, formed over thousands of millennia. In 1959 the English-born Kenyan palaeoanthropologist Mary Leakey came across an exceptionally complete skull in the Olduvai Gorge, along with stone tools. The specimen became known as Zinjanthropus boisei (Zinj), and was given the species name Paranthropus boisei. Previously it had been thought that such pre-humans lived 500,000 years ago but, to the surprise of contemporary scientists, Zinj could be dated to 1.75 million years ago, and his teeth suggested he was a grazer.

I was relieved to see there was a plaque at the spot where Zinj had been discovered, acknowledging Mary Leakey’s pioneering discovery. She was a feisty and formidable woman who had received only sporadic teaching but showed an exceptional talent for archaeology and excavation. She married a Cambridge archaeologist and anthropologist, Louis Leakey, and they moved to East Africa in the late 1930s and established a site at Olduvai Gorge. As a woman working in a field dominated by men, much of the credit for Mary’s earlier contributions went to Louis.

Homo habilis, 1.7 million years ago
In 1961, Mary and Louis Leakey’s diligent efforts paid off with another major find in Olduvai: a partial skull and a lower jaw dating from 1.7 million years ago—making the specimen a bit younger than Zinj. The plot thickened: the skull was much more similar to our own than Australopithecus or Paranthropus. It had a large brain chamber, and so this hominin would have enjoyed using its hands in a more sophisticated manner with fingers that could hold and manipulate objects, such as stones and tools for cutting meat off the bone. He was named Homo habilis, Latin for “dextrous man.”

Turkana Boy or Homo erectus, 1.5 million years ago
In 1984, a team working under Louis and Mary’s son, Richard Leakey, made a startling discovery that filled a huge gap in our knowledge of human evolution. They found remains in the Turkana Basin in northern Kenya that provided stunning evidence of the group that would eventually lead to us. This was Turkana Boy or Homo erectus, meaning “upright man.” He lived 1.5 million years ago and, unlike other lines such as Homo habilis that died out, Homo erectus survived and evolved. Turkana Boy was prepubescent—probably about 12 years old. His skeleton is the most complete of any hominin found so far. He stood a meter and a half tall.

Most experts believe that Homo erectus acquired the knowledge of how to start a fire by rubbing together flintstones, so his ribcage (and therefore guts) as well as his teeth were smaller due to eating softer, cooked food, which enabled his brain to grow more quickly as protein intake increased. At around the same time, language, probably involving the extensive use of tongue clicking, developed. Turkana Boy is likely to have communicated in this way. Homo erectus’s brain grew ever larger, until around 400,000 years ago this hominin became the archaic Homo sapiens. Two hundred thousand years later, Homo erectus had fully developed into Homo sapiens, anatomically the same as us. Homo sapiens sapiens, the modern human, was fully formed genetically about 100,000 years ago.

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Excerpted from An African History of Africa: From the Dawn of Humanity to Independence by Zeinab Badawi. Courtesy of Mariner Books/HarperCollins Publishers. Copyright © 2024 by Zeinab Badawi. Featured image: Noel Feans, used under CC BY 2.0.