The Sediments of Time
Page 1
Contents
* * *
Title Page
Contents
Copyright
Map
Prologue
Part I
Beginnings
A Change in Track
Racing Against the Clock
Changing of the Guard
Part II
Water, Water Everywhere
A Brave New World
Nine Lives
A New Early Biped
Another Piece of the Puzzle
Open-Country Survivors
A Friend for Lucy?
Photos
Early Homo: A Horrible Muddle
Part III
Becoming Grandmas
Growing Brains
The Icehouse
The First Explorers
A Very Good Hominin
Through Thick and Thin
Migrating Mutants
Epilogue
Acknowledgements
Sources
Index
About the Authors
Connect with HMH
Copyright © 2020 by Meave Leakey and Samira Leakey
All rights reserved
For information about permission to reproduce selections from this book, write to trade.permissions@hmhco.com or to Permissions, Houghton Mifflin Harcourt Publishing Company, 3 Park Avenue, 19th Floor, New York, New York 10016.
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Library of Congress Cataloging-in-Publication Data
Names: Leakey, Meave G., author. | Leakey, Samira, author.
Title: The sediments of time : my lifelong search for the past / Meave Leakey with Samira Leakey.
Description: Boston : Houghton Mifflin Harcourt, 2020. | Includes bibliographical references and index.
Identifiers: LCCN 2019050624 (print) | LCCN 2019050625 (ebook) | ISBN 9780358206675 (hardcover) | ISBN 9780358308942 | ISBN 9780358311799 | ISBN 9780358171911 (ebook)
Subjects: LCHS: Leakey, Meave G. | Paleoanthropologists—Great Britain—Biography. | Women anthropologists—Great Britain—Biography. | Paleoanthropology—History.
Classification: LCC GN50.6.L43 L43 2007 (print) | LCC GN50.6.L43 (ebook) | DDC 599.9092 [B]—dc23
LC record available at https://lccn.loc.gov/2019050624
LC ebook record available at https://lccn.loc.gov/2019050625
Illustrations by Patricia J. Wynne © 2020 by Houghton Mifflin Harcourt
eISBN 978-0-358-17191-1
v1.1020
Prologue
Never before has a species been as intelligent as we are or as able to achieve the technological innovations that we have. We can plumb the depths of the oceans and penetrate far into space. We can understand the smallest particles that make up matter and probe the farthest planets in the galaxies. New innovations, new theories, and new breakthroughs are reported every day. We have better communication tools than ever before. With the advent of the Internet and the power of our smartphones and social media, we can communicate with almost every individual on the planet, and we know what is happening everywhere in the world almost as soon as it happens in real time. This is truly extraordinary.
The earliest stone tools were first fashioned more than three million years ago, but the wheel was not invented until around 3500 BC. Today, new innovations appear with increasing rapidity and complexity; the first landing on the moon was in 1969, now we can land on Mars and explore the far reaches of space. In 2017, the international collaboration between two hundred scientists and the combined magnification power of seven telescopes spanning the globe culminated in the seemingly impossible: photographing the event horizon of a supermassive black hole at the heart of the Messier 87 galaxy, nearly fifty-five million light-years away from Earth, thus putting proof to what had previously been an abstract theory. And our technological capacity continues to increase at an exponential pace. This potential to achieve such mind-boggling accomplishments—relying on the combination of technical knowledge, our capacity for abstract thought, and our ability to work cooperatively—represents the pinnacle of our human capabilities.
Our past is full of twists and turns that ultimately led to the species we are today. Our extraordinary accomplishments can be traced back in time through the major milestones of our evolution. The body plan and complex hierarchical social structure of primates provided the latent potential for all the key adaptations that now separate us from other animals. Swings in global climate provided the main impetus for crucial adaptations to occur. Driven by the drying trend towards more open savannah, we left the safety of the trees to begin our bipedal journey, thus freeing our hands for more manipulative tasks. Changes in diet provided the calories necessary to grow our enormously expensive brains to the size they are today.
No part of our evolution could have been anticipated as an obvious outcome of a prior development. Nevertheless, the sequence of adaptive changes our ancestors underwent were the essential stepping-stones that define the species we ultimately became. This process was in no way preset. The course of our evolution could have been very different, and we might have become a very dissimilar being.
I have been fortunate to spend my career studying and exploring human evolutionary developments, and I have come to fully appreciate the importance of the past in charting a direction for our future. But harder to predict and foresee is the impact of our extraordinary technological developments. The rapidity with which human technology is increasingly driving our lives today is a potential threat and, at the same time, seemingly the best and only hope for our species. We are able to better predict the negative consequences of a future in which we continue to willfully destroy the environment on which we all depend. For our species to survive, we must protect the natural resources that sustain us.
As I write this, it feels like we are hurtling ever closer to some sort of tipping point. The threat of man-made climate change is growing inexorably more immediate and urgent, and the dizzying speed at which information can now spread across the world has upended the traditional political and media culture that has prevailed through most of my life. Science and truth, the bedrocks of rational thought ever since the Enlightenment, are now once again contested arenas: a seismic shift whose consequences we cannot predict and are only starting to bear witness to.
This is a book about personal—and collective—discovery. It recounts the events that have led to our current understanding of our past, which was very minimal when I began my career. We have a much more detailed record today and can fill in many of the gaps. Species come and go and are replaced over time by newly evolved, better-adapted forms. This is the ever-changing face of evolution.
Although we cannot determine physical evolutionary changes, we are able to direct technological ones. While technology can be put to many beneficial and productive uses, it can be extremely dangerous if misused. As our capabilities expand, so does the capacity to do irreparable harm. This is much closer to home for many of us than ever before, with many new questions arising each year about how best to regulate research in artificial intelligence, genetic engineering, drone use, and other cutting-edge fields. Alongside these is the greatest challenge of all: what we are to do to address the threats posed by the warming of our planet?
Our challenge is to ensure that we direct our extraordinary technological abilities along channels beneficial to all humanity and the planet. I have no doubt in my mind that we have the mental and technological capacity to prevail. The question is whether we can summon the collective will to do so. To me, these facets—our ability to solve intractable problems and overcome insurmountable odds in opposition to the impulsive, willful, and selfish parts of our human nature—are the dichotomy that defines our uniquely human cha
racter. Our continued success as a species depends on our choices about which of these evolutionary traits we will allow to dominate our collective future. I have written this book in the hope that readers develop this essential perspective based on a better understanding of our past.
—Meave Leakey, October 2019
Part I
1
Beginnings
It was the end of a long hot day scouring for fossils not far from the eastern shore of Lake Turkana, known in 1969 as Lake Rudolf. We were clustered around a small dying cooking fire. Against the rich black darkness, the stars crowded the sky, looming so large and close that it felt as though you could reach out and touch them. A cool breeze rustled the thorny bare branches of nearby wait-a-bit bushes, bringing welcome relief from the searing heat. Our camels were gathered together, legs hobbled. They gurgled and groaned in the manner peculiar to their species, and their chorus carried to where we sat on the stony ground.
As the slender crescent of the moon sank slowly toward the horizon, an animated discussion erupted. Just two weeks earlier, we had gathered together under the same starry sky at our base camp to listen to a crackling voice proclaim over the short-wave radio: “That’s one small step for man, one giant leap for mankind!”
Peter Nzube Mutiwa, a spry young man with extremely sharp eyes and an equally sharp sense of humor, was still in total disbelief. “How could there possibly be a man up there in the sky, standing on the moon?” he demanded, yet again adamant that this Neil Armstrong character simply had to be an American fabrication. Pure propaganda, designed to convey US superiority in a cold-war era, which had cast its pall even in this far-flung corner of Kenya.
No wonder Nzube, who preferred to use his Kamba name, was so disbelieving—the contrast between our surroundings and the technology that led to this breakthrough could not have been greater. A wild and remote area, the Lake Turkana region of Kenya is inhabited by the Dassenetch, a local tribe who, at the time, lived by the minimum of technology. Their pastoral lives still depend largely on their sheep and goats to this day, reflecting a major revolution in the way humans relate to the natural world, one that saw us control the number and destiny of animals and plants. Yet in many respects, their pastoral ways were continuous with a deeper, foraging past and were not dissimilar to those of humans living hundreds of thousands of years ago. In 1969, small groups of men habitually followed the lakeshore in canoes crudely crafted from gouged-out tree trunks to supplement their diet with fish and turtles. They foraged for whatever edible plants they could find in the sparsely vegetated desert landscape. If they needed to cut something up, they fashioned a stone tool. To cook their food, they made a fire on the lakeshore or in the bottom of a hardwood canoe using two sticks and some tinder from a ball of dry, fibrous herbivore dung. The meal might be eaten out of a tortoise shell that served as a bowl. Carrying few possessions and apparently feeling no need for them, the Dassenetch could find everything they required readily available from their barren surroundings.
Surrounded by the simplicity of this life in the desert, it was even more difficult to conceive just how big a leap mankind has taken to have ended up not only on the moon but also as the supremely dominant species here on Earth. Both achievements are thanks to the advantages conferred by technology, which continues to evolve at a dizzying pace. Gazing at the glowing embers of our dying campfire, it occurred to me that the same impulse that landed a man on the moon had found us gathered together on the stony ground that night: a burning desire to know where we came from. What makes us special? How did we come to be here? And what happens after we die? These questions would go on to drive my career. They are the same questions that have compelled people for thousands of years.
* * *
MY COMPANIONS were just the sort you would choose for an expedition in the remote world of Lake Turkana in 1969. Peter Nzube had worked at Olduvai Gorge in Tanzania with Louis and Mary Leakey for many years. Always the source of much entertainment and a great storyteller with a mischievous sense of humour, he loved to regale us with tales of excavations under Mary’s strict and unforgiving supervision. A perfectionist to her core, Mary simply would not tolerate sloppy work in the excavations.
Kamoya Kimeu, like Nzube, was from the Kamba tribe, a farming people who live on fertile terraced lands south of Nairobi. He too had worked with Mary at Olduvai Gorge and knew her son Richard as a teenager. Over the years, Nzube and Kamoya had built a strong friendship with and loyalty to Richard. Kamoya took life more seriously than Nzube; reliable, and solid, he was the master of difficult logistics and never happier than when looking for fossils in a new place. Both men had eagle eyes, and between them, they had already at this early point in their careers found some of the most important fossils from East Africa.
Across the fire from me was Richard, the handsome, bold, and daring Leakey who had already made strides in carrying forward the palaeoanthropological work started by his parents. This expedition was his brainchild, and he had invited me along for my newfound expertise in monkeys. I was in Kenya at the behest of his father, Louis, who had tasked me with helping run a monkey breeding and research centre at Tigoni in the highlands near Nairobi.
Beneath this magical moon in the rugged, expansive northern desert of Kenya, I was blissfully happy. Just twenty-seven years old, I was thrilled—if surprised—to have this rare opportunity to be counted among this circle of talented individuals. The desert of Africa was not at all where I had expected to find myself. Newly graduated from the University of Bangor in Wales, I was technically a marine biologist. Or so I had planned, with my freshly minted joint degree in zoology and marine biology. But behold the world in the late 1960s. Homo sapiens had not, apparently, evolved so far as to allow female marine biologists onto ships. “We cannot employ you because we don’t have the facilities for you,” I had been told time and again by the men running the expeditions. When I had chosen my degree, I didn’t know about this important technicality, and it is testament to the open-mindedness of my parents that I had never once questioned my birthright to be a scientist alongside these men. But in the sea of gently undulating desert plains, this obstacle was easily overcome because there were no “facilities” at all!
* * *
I WAS BORN at Guy’s Hospital in the middle of the London Blitz in 1942. I don’t remember very much about my early years, but I am told I was a fractious child, anxious and often crying, presumably because of the highly unsettling incessant bombings during my childhood. When I was eleven months old, my father was deployed to Corsica, leaving my mother and me alone in a bungalow in Orpington just outside of London, plum in the middle of London’s deterrent “balloon barrage.” This strategy to protect London against bombing during the war consisted of a great number of inflated airships that were kept circling above by a ground operator. The German bombers could not fly below the altitude of the airships without becoming ensnared in the multitude of steel cables anchoring them to the ground. Orpington was also home to bright searchlights and antiaircraft guns positioned to catch the German bombers on their way in to London. It was a noisy and grim place to live. Our days were constantly interrupted by wailing sirens, which would pierce the air, startling everyone. During air raids, we slept in a Morrison shelter—a strong iron structure that doubled as a kitchen table and could withstand the weight of a small house collapsing on it, the theory being that you would be safe inside its metal walls until somebody could dig you out of the rubble. But I don’t believe much sleeping was done in our shelter.
“Noise, Mummy, noise,” I’d cry, drawing myself up rigid and screaming at the top of my lungs. Nothing and no one could console me. My exhausted mother eventually decided to get me away from all the raids, and we moved to a much more rural and rustic setting near Tunbridge Wells. Robingate Cottage was very isolated, with a great metal bath by the front door in the kitchen and a chemical loo out the back. Apparently, if the baker dropped by when my mother happened to be in the bath, she simply po
pped the lid on and lay there quietly until he went away! My father’s sister Margaret would wrangle time off from her busy job managing the medical stores and dispensing supplies for the Women’s Auxiliary Airforce to visit my mother and help her out with me. There were no other children nearby, but my mother encouraged me at a young age to learn about natural history and observe all living things. I needed little urging. I always had beetles, frogs, caterpillars, and other delights tucked away somewhere about my little person, and (apparently) I was always trying to add my “wems” (worms) to the cooking. In a short while, the woods filled with rabbits, flowers, and quiet birdsong worked their charm, and I began to recover from my anxieties.
But we quickly learned that Robingate, while not directly on the Germans’ flight path to London, was close enough. Antiaircraft guns were stationed close by, and the terrifying shrill sirens of air raids soon followed us to our new home. After one such week of endless raids, in which I rapidly dropped a pound of weight, my mother decided to get me away yet again. Throughout the war, we continued to move around, sometimes returning to Robingate, at other times staying with my mother’s sister, Wynn, and her husband, Eric, at the big rambling vicarage in their Norfolk parish.
On many occasions, I was left at a nursery run by two marvellous women named Beryl and Gerda in South Newington. Beryl, whom I called Taya, was a wonderfully warm, buxom person who became a second mother to me during my rather frequent stays in her nursery. It was mainly in her care, away from the sirens and bombs, and with other children to play with, that my terrified existence was replaced by more normal childish pursuits.
My mother no doubt struggled with leaving her child in another’s care for any length of time, but she must have been immensely relieved to have found a place where I was not perpetually afraid. I cannot imagine what it must have been like for her—and many mothers like her—with a husband serving in a dangerous war, a frightened child, and very little food.