At first sight, it seems an improbable new tourist destination — a patch of barren, gritty hillocks on the remote sun-scorched plains of north-western Kenya.
But the Turkana Basin was not always like this. Three or four million years ago there were reeds or marshy grasslands at this site, says paleontologist Louise Leakey. It was the edge of a lake or river. She finds a length of grey rock lying in the dust and identifies it as a fossilised hippopotamus bone. Other fossils recovered from this ancient layer of sediment show there were elephants, crocodiles and gazelles here. Also living precariously among those creatures were at least two species of hominins, the distant, upright-walking ancestors of our own species, Homo sapiens.
Leakey, the third generation of a family of celebrated paleontologists who have done much to unlock the secrets of man’s origins, knows this because twice in the past two years, her field workers have found hominin teeth here. One rectangle of stones marks where they found “four socking great molars”, nearly an inch across, suggesting that this hominin ate very tough vegetable matter. Another shows where they found several smaller, more pointed teeth.
Leakey is cautiously excited. They differ from any hominin teeth found before, she says. They could, conceivably, belong to a couple of hitherto unknown species; they are clues that offer a “tiny window” into pre-history. They could provide another small piece of the giant jigsaw that will eventually answer those fundamental questions: “Who are we? Where did we come from? And how did that happen?” That jigsaw is far from complete but the Leakeys and their fossil-hunting team have unearthed some of the most important pieces to date.
In a Tanzanian gorge in 1959, Leakey’s grandparents Mary and Louis unearthed the skull of a 1.8m-year-old hominin that they named Zinjanthropus boisei. “Zinj” gave rise to the then revolutionary idea that man originated in Africa. Not long after, their oldest son Jonathan found the partial remains of a species they called Homo habilis, or “Handy Man”, which raised the equally revolutionary idea that more than one species of early hominins lived contemporaneously.
In 1967 Leakey’s father Richard made yet another discovery: fossil-rich sediments near Lake Turkana, the world’s largest desert lake, which stretches 180 miles from the Omo delta into the arid scrubland south of the Ethiopian border. Throughout its 7,000-sq mile basin, the tectonic movements of the Great Rift Valley had thrust ancient sedimentary deposits back to the surface, exposing all manner of fossilised remains. One sensational find followed another: the skull of the oldest known Homo erectus (1.9m years old); the almost complete skeleton of the Turkana Boy (1.6m years); the oldest known Homo sapiens (195,000 years) and, overall, nearly half of all the fossil evidence for human evolution so far discovered.
From next year, Leakey intends to host occasional groups of wealthy visitors here. She admits she is doing it for the money — not for herself, but to fund the Turkana Basin Institute, which her father established to support scientific research in this so-called “birthplace of humanity”. “It’s the world’s best field lab for looking at our past,” she says.
Guests should not expect luxury. Although tours will begin and end in the comfort of the Solio and Sasaab game lodges much farther south, there are no hotels in this impoverished corner of Kenya. They will stay at one of the TBI’s two field centres — Turkwel on the lake’s western side or Ileret on the east, and, for a couple of days, one of the world’s foremost paleontologists will guide them exclusively around the world’s finest repository of fossils.
Leakey knows the basin better than anyone, and her enthusiasm is contagious. As a baby she would sit in a tub of water to keep cool while her parents excavated sites around Turkana. At the age of 12, she was driving their Land Rover over the parched landscape. By 21 she had taken charge of their research programme after her father lost his legs in a plane crash and her mother Meave flew him to London for treatment.
She has us hunting for fossils near mysterious stone circles where, 10,000 years ago, early humans buried their leaders. We find fragments of turtle shell, a crocodile vertebrae, fish bones and oyster shells. Her work is painstaking, the conditions harsh, but to discover the skull, mandible or hand of a human ancestor that has lain unseen for a million years is, she says, “a moment you will always treasure”.
At the Turkwel field centre she shows us a roomful of workers cleaning and piecing together tiny fragments of fossil, before producing a succession of skulls that look progressively more human. Then she introduces us to Sonia Harmand, a French archaeologist from New York’s Stony Brook University.
“These are the oldest stone tools in the world,” says Harmand, placing some rocks on a table. She and her paleontologist husband Jason Lewis spotted them after getting lost walking here in 2011. There were about 150 in all, and turned out to be 3.3m years old — 700,000 years older than any previously found.
The rocks look innocuous but Harmand points to fracture marks where man’s distant ancestors chipped off sharp-edged flakes. They would, Lewis explains, have used those flakes to cut meat from carcases killed by other carnivores. This, they contend, was the point at which hominins gained dominance over other animals. With reliable access to good-quality meat, they grew bigger and stronger — though another 2.3m years passed before they learned to use sharpened stones for actual hunting. “Since I was 18 I’d wanted to find the world’s oldest stone tools, and I did it,” says Harmand. “It was like a dream.”
Leakey offers a journey back through time — but even reaching the institute to begin that journey is an adventure. The basin is far from Kenya’s usual tourist routes, and driving from Nairobi would take days, so we fly up in a chartered helicopter over some of the most spectacular scenery on earth.
Beyond the highland moors and forests of the Aberdare National Park, our helicopter swoops down to the Great Rift Valley. We skim over the wildlife conservancies of the Laikipia plateau, admiring elephants and rhinos on the savannah, hovering over a pride of lions, scattering giraffes and zebras, oryx and impala. Beyond, community lands are dotted with the thatched huts of semi-nomadic goat- and cattle-herders, and far to the east the snow-capped peak of Mount Kenya protrudes from clouds.
When we land on the rim of the Silali crater — a perfect circle three miles in diameter — young girls from the Pokot tribe appear, hair dyed ochre with mud, sandals fashioned from old tyres. Their skin is notched with decorative scars, and they giggle with delight at their reflections in the side of the helicopter.
With the helicopter’s doors open, we roar low over marshy lakes as panicked crocodiles slide into the water. Then it’s down a narrow river gorge, banking left and right, to admire the colours of the Painted Valley, great boulders perched on eroding towers of softer rock, and red clay termite towers 12ft high.
We land again on the pristine Suguta sand dunes — an undulating yellow sea ringed by a black volcanic moonscape. As Leakey charts our progress on her iPad, we speed over miles of lifeless lava fields to Lake Logipi, where thousands of pink flamingoes take wing at our approach. Beyond a final volcanic ridge Lake Turkana stretches away to the horizon: a vast expanse of shimmering turquoise known as the “Jade Sea”.
In the tiny fishing communities on the lake’s shores, the men of the Turkana, Dassanech and El Molo tribes catch tilapia, tiger fish and Nile perch from simple wooden boats or primitive log rafts. Women festooned with colourful bead necklaces gut, salt and dry those fish in the hot sun. Some are using sharp stones to gouge out the innards, much as Harmand’s ancient hominins might have.
We reach the Turkwel field centre acutely aware of the enormous technological advances our own branch of mankind has made in the past half-century, but Leakey warns against the arrogance of modern man. She reminds us that we have existed a mere 200,000 years, and that all the half-dozen other species of the genus Homo have gone extinct.
Since her grandparents first started searching for man’s origins 80 years ago the global population has soared from two to seven billion. She says man is rapidly destroying the environment and other species in what she calls the “sixth Mass Extinction”. She believes Homo sapiens will itself disappear “possibly within hundreds, not thousands, of years”, adding: “The planet would be a better place without us”.
Even in the Turkana basin the warning signs are apparent. The wildlife has mostly been killed. Overgrazing has turned the land to desert. Overfishing has depleted the lake. Ethiopia has built a huge new dam on the Omo river which threatens to turn sublime Lake Turkana into a toxic, dried-up dust bowl. “Here in the so-called ‘Birthplace of Humanity’,” says Leakey, “you can already see how humanity is destroying itself.”