THE AREA OF HADAR FIRST MADE HEADLINES IN THE 1970S WITH THE DISCOVERY of the most famous of the Australopithecine fossil remains, nicknamed “Lucy” by the paleoanthropologist who discovered her, Dr. Donald Johanson. Lucy was one of the most complete fossil skeleton hominids ever recovered. She was a rarity in a world where modern fossil hunters or paleontologists celebrated even an occasional tooth find. Her incredible state of completeness and preservation hinted at just how special Hadar would become as a source for hominid prehistory and history. Lucy continues to be the unofficial “spokesperson” for Hadar and its unparalleled ability to help us address what it means to be human.
To visit Lucy’s homeland, one needs to return to her African roots, specifically the region of Hadar in Ethiopia, where the world’s richest fossil database on human ancestors continues to yield fascinating new windows into the ancient world of hominids. I first visited the region a decade ago while working on an archaeology expedition seeking clues of ancient seafaring along the African coast. Political instability and red tape led to a number of unexpected free days, and some of us decided to head inland to visit the land of our ancestors in Ethiopia. Dr. Johanson’s finds had made Hadar and the Afar Triangle famous. Perhaps we would find a “Lucy” or other significant fossil, we thought. Well, we had no such luck, but during our journey we learned why the Rift Valley and Hadar were yielding so much information on hominids.
Hadar is a proverbial “gold mine” of human and animal fossils and artifacts from six million years ago to modern times. This is the very time postulated in evolutionary theory for the emergence of humans from earlier primate animal forms. The action of plate tectonics produced the Great Rift Valley, the Afar Triangle, and, specifically, the Hadar depression. Thus, the earth is literally splitting apart and exposing ancient deposits from millions of years ago. These deposits of soil and rock are what have fossilized and protected the remains of our ancestors. If we listen and observe at Hadar, we learn that we are not so different from these early bipedal species.
Even in modern times Hadar promotes adaptation to changing environments. To get to the Hadar area, we hired a car and driver to help us negotiate the volatile political, tribal climate as well as the sand and rock trails that sometimes substitute for roads. Our driver was well versed in local road and political conditions, and he handled the necessary small gift exchanges (bribes) that allowed us to pass various checkpoints—some official and some not so much. After a grueling twelve-hour car trip we reached Elowha village in the heart of the Afar triangle. My colleagues were road weary, so they decided to visit a local market known for indigenous goods, find something to eat, and then do an exploration on their own; they were sick of the car. I was too, but I asked the driver to take me to a local bar so I could refresh myself. The driver and I ended up at a local “bar”—really just a watering hole, locally known as Lussy’s and named for the famous find of Lucy. I learned that we were only thirty miles (fifty kilometers) from Afar Locality 288, where thirty-one-year-old Dr. Donald Johanson and Tom Gray first found Lucy in 1974. Refreshed, I began to get the “fever” that every person who shares a fascination with finding remains of the past gets. In less than thirty minutes by Land Rover, I found myself amidst the sandy slopes that held Lucy’s secrets for over three million years. I took a walk around the sandy slopes in the blazing sun. Maybe it was the sun or the weary trip, but I felt like I was walking in the steps of Lucy across the same landscape our ancestors did millions of years ago and just as the Johanson expedition did over three decades ago.
Fossils of animals and human ancestors are quite prevalent in the area. As this chapter will show, over four million years ago in East Africa human ancestors began to walk upright (bipedalism) as an adaptation to a mixed landscape of riparian forests and savannah grasslands. Known as “hominids” in modern scientific terms, their ability to walk upright resulted in physical and behavior adaptations such as tool making and use, nutrient-rich diets, and, eventually, larger brain size. These adaptations allowed for migrations out of Africa and the spread of modern humans across the globe, thus leading to the modern world we know today.
Yet it was not at all clear that early hominids would survive and thrive in East Africa just because they could walk upright and use simple stone tools to adapt to a changing environment. The fascinating story of how our hominid ancestors survived and thrived is best “read” through fossils and artifacts recovered at East African sites along the Rift Valley, where bipedalism and tool use first occurred in hominid populations between six million years ago and the emergence of modern humans starting around two hundred thousand years ago.
HADAR AND THE WORLD: The Center of Humanity
The site of Hadar in the Afar Triangle at the north end of the Rift Valley in Ethiopia is considered the most important site and area for telling the story of the emergence of humanity. (See Map 1.1.) Hadar is a depression landform located in the Afar triangle about 1,640 feet (500 meters) above sea level. The Afar Triangle is geologically famous as the meeting place of three tectonic plates—Nubia, Somalia, and Arabia—that form the African Rift valley system, home of some of the most important early human ancestral fossils in the world. Like much of Africa, Hadar is a hard place to get to because of geography, weather, and political climate. The hot summer days and cool winter nights remind us of just how contrasting and extreme human ancestral adaptation has been for the past few million years. Africa’s topography is not so different today from what it was like six million years ago. Wind and water have heavily eroded Hadar’s 262 feet (80 meters) of sandy deposits, revealing fossilized bones from the origins of human time. This landscape holds the key to understanding how humanity emerged from our complex relationship with and adaptation to the environment.
Map 1.1. Migration Out of East Africa and the Great Rift Valley
The Great Rift Valley of East Africa is produced by plate tectonic activity in the earth’s subsurface layers. In northern Ethiopia, three plates collide in the Afar Triangle, with Hadar at the heart of the collision zone, providing a unique geographic setting that has been the backdrop environment for the earliest human evolution. The Rift Valley has proven to be an evolutionary “highway” with early human ancestors moving north out of Africa and departing Hadar for the rest of Eurasia and the world ever since human ancestors began to walk upright.
From sites like Hadar, researchers known as paleoanthropologists are reconstructing this story in fascinating detail. Due to their efforts, we know that numerous species associated with two genera in particular, Australopithecus and Homo, were and are key to understanding the physical and cultural evolution adaptations that led to us and our modern human civilization.
Recent finds at Hadar and in the Rift Valley of East Africa also indicate that Lucy’s relatives did not just walk upright but also utilized early tools—simple stone tools for cutting and concussing. It is thus with Lucy that the first signs of being human emerge. She recently finished a tour of US museums in her first journey “out of Africa.” Her genus, the Australopithecines, never made it out of Africa, but her descendants did. This was the genus Homo that in several waves spread out of Africa and across the globe. Today we modern humans are called Homo sapiens sapiens, and we owe our success to these early physical adaptations (bipedalism) and cultural-behavior adaptations (tool making) that Lucy and her Australopithecine relatives first developed.
Thus, the ability to walk upright—specifically, “habitual bipedalism”—is what led to the modern human world. It freed up the hands, increased vision, and led to complex diet and brain growth. But of utmost importance, walking upright gave rise to the most critical human adaptation of all: tool making and tool use. With tools, bipedal hominids no longer needed to change physically for successful adaptation to an environment; they could manufacture and use tools that changed the environment for them. Lucy finally did make it out of Africa in her recent tour, ironically on complex tools like jets and ships that were made possible by her adaptations, which she helped “test out” almost four million years ago!
Lucy: The Find That Made Hadar
For fossil finders around the globe, nothing comes close to the excitement Donald Johanson and colleagues felt the day they discovered Lucy, one of the most complete sets of Australopithecine remains found to this day. The team arose at sunrise, and after a cup of thick, black Ethiopian coffee (Ethiopia is the original birthplace of coffee beans), they headed for an area that had yielded ancient animal remains a short drive away. Animal fossils had been found in the area suggestive of a riparian or stream environment, though from a different time and sedimentary layer from those that usually yielded fossilized hominid remains. Nonetheless, Johanson and graduate student Tom Gray wanted to explore the area further anyway. They dropped off geologists and then combed the area for several hours before Johanson spotted a hominid elbow. This was followed by what eventually became the fossilized remains of a 65 percent complete hominid. Johanson and Gray were beside themselves! They could not wait to get back to camp and share their find.
Lab analysis revealed the remains to be those of an adult female Australopithecus aferensis. Johanson had made the find of finds: a relatively complete fossilized skeleton of an upright hominid from over three million years ago that helped fill in the so-called “missing link” of human evolution. This was the supposed gap that many critics of evolution suggested existed between ancient, primate-like fossils that did not walk upright and more recent, human-like fossils that clearly did walk upright. Lucy resembled an upright chimpanzee in some ways but had other features suggestive of later hominids.
But the find needed a name. Over the next few days several were proposed, including Dinkinesh, meaning “you are marvelous” in local Amharic vocabulary. However, Johanson’s girlfriend, Pamela Alderman, proposed the name we know as the group celebrated over a campfire dinner of roasted goat, fried potatoes, and Bati beer. The tape player wafted the lyrics from “Lucy in the Sky with Diamonds” across the cooling desert night. The song was from the Beatles’ album Sgt. Pepper’s Lonely Hearts Club Band, and the name stuck. Today Lucy and the Hadar region continue to inspire a new generation of fossil hunters seeking to answer pressing questions of evolution and hoping to make a field-changing discovery just as Johanson did over three decades ago—a find made by walking the landscape just as our ancestors did for millions of years at Hadar.
Hadar as the Center of Humanity
Beginning in the late 1970s and continuing today, thousands of fossilized bones and tools have been discovered at Hadar. The area’s geomorphology (short-term land-form processes), geology (long-term land-form processes) along with limited modern-population impacts are partly responsible for the unique preservation and exposure of fossils at Hadar. Its ancient climate and biome must also have been a great draw for hominids. The animal fossils, pollens, and erosion evidence indicate that Hadar was a much wetter region during early fossil hominid times. Its environment oscillated several times between forested streams and receding forests. As the forests and water supply receded, grassland savannas took over. Together these factors resulted in the attraction, protection, fossilization, and then, finally, exposure of the greatest number of ancient potential human ancestors ever found. The database that continues to emerge at Hadar may turn out to be greater than the entire global database for all non-Hadar (Afar Triangle) databases combined! As of 2010 both the quantity and quality of these fossils is unparalleled when compared with any other paleontology site in the world.
Today we classify this general group of bipedal, upright species and possible relations and ancestors as Hominoidae. Dr. Johanson prefers the term “hominid” for bipedal issues, but modern researchers also use the term “hominin.” We will utilize hominid in honor of Lucy (Dinkinesh) as the first major discovery at Hadar and the one that placed Hadar on the map. Today Hadar is the preeminent place to search for answers to the question, “What does it mean to be human?” It is a question at the very heart of our existence.
Lucy and the First Family
Lucy was not alone at Hadar. Counting Lucy, the fossil specimens of Australopithecus aferensis found at Hadar to date number over 360 individuals—far more individual specimens than are known from any other paleontology site in the world. It is not clear, however, if this means that the ancient Hadar region between three to four million years ago held a greater population density due to better environmental resources or if that this is simply due to the unique preservation traits and modern geologic exposure traits underway at Hadar.
This collection of 360 individual fossilized remains, discovered over the past three decades, is collectively and affectionately known as the “First Family” of humanity. It is by far the largest concentration of an ancient species of hominids ever found. Only at Hadar can paleoanthropologists who study fossil remains of past human ancestors hope to find detailed answers to their questions about hominids. These include biological and social questions concerning adaptation, origins, and quality of life as well as questions about social groups, diet, and lifespan. Today we know that Lucy and her species were only one of several Australopithecine species in the African savannahs and forest lands between four and one million years ago. Her species was particularly gracile, or slightly built, but with variable heights from 3 to 5.5 feet tall, weighing around a hundred pounds, and having brain casings around 400 to 500 cubic centimeters. Lucy and her kind walked upright regularly and had larger brains than modern primates such as chimpanzees. They ate mostly a fruit, plant, and insect diet that would be unfamiliar to us today, whether vegetarian, omnivorous, or carnivorous. Lucy and her companions lived only to thirty years or so if they made it to adult status. Modern humans average twice the lifespan and have a brain three times the size of Lucy’s. Hence, Lucy was closer in build and lifespan to early Homo genus species like Homo habilis from around 2 million years ago than she was to modern humans. The Homo genus first emerged alongside or perhaps from the Australopithecines around 2.6 million years ago in East Africa, including at Hadar. Homo migrated out of Africa as efficient bipedal species that made and used stone tools. Several species of the genus migrated across the globe in waves that eventually led to modern humans, or Homo sapiens sapiens.
Although there is debate over whether the Australopithecines genus developed tools even earlier than Homo, researchers have found at Hadar the earliest stone tools definitely associated with the Homo genus, dating from 2.6 million years. These are called Olduwan-style stone tools, and they are common across Hadar. Olduwan stone tools were the first stone-tool industry in the world, and they show up first in the Rift Valley between 2.6 and 1.7 million years ago. Olduwan tools are characterized by simple choppers made from breaking river cobble in half to obtain a sharp cutting and concussing edge but with a smooth, round hand-hold on the opposite side. Additionally, simple uniface and biface scrapers as well as cutting tools characterize the Olduwan tool industry. Unifaces and bifaces are stones that hominids worked purposefully on one or both sides to obtain a sharp edge for cutting but not usually for concussing.
The Australopithecines (4 million to 1 million years ago) and the Homo genus lines (2.6 million years ago to present) overlap each other in time and space at Hadar and in Africa in general, making interpretations of culture difficult. The concentration of Lucy-like individuals at Hadar and the presence of various stone-tool assemblages all suggest basic social organization for the purposes of adaptation to a mixed forest and savannah-like environment several million years ago. At Hadar, hominid groups needed to access stone tool–making material, water, and food in territorial units that matched their social unit size. Researchers believe such basic social units as a family or band would be necessary, as infants could not care for themselves for at least the first few years of life.
Unfortunately, the inability of relative and absolute dating systems to narrow the times for hominid fossil and tool discoveries to more than a few thousand years currently makes it impossible to explore the exact nature of the relationships between Australopithecines and the Homo genus lines or even to distinguish culture traits at sites with mixed associations. So currently researchers cannot address whether these two genera were in contact with each other between the span of 2.6 million years ago, when Homo first appears, and 1 million years ago, when Australopithecines die out at Hadar and East Africa in general.
What researchers can be certain of is the early hominid relationship with the environment at Hadar. The small size of hominids, whether late Austrolopithecines or early Homo, indicates a limited range in terms of how far individuals and groups could cover in a day or a season. Animal fossils and sediment layers indicate that Hadar’s location on an ever-expanding Rift Valley system in East Africa may have been key. This was a land of climate and biome change, albeit over thousands of years. Thus, many species of plants and animals called it home over the course of hominid times. Hominid species could take advantage of the concentration of resources along the north-south-running Rift Valley in East Africa by walking to the resources and utilizing basic tools to adapt to those resources. Perhaps the emerging and changing Rift Valley system promoted migration up and down its length. Perhaps certain hominid groups simply moved within a local landscape to seasonal resources or to resources that varied by elevation and landscape. We can never know for sure because the environments changed across six million years of hominid occupation at Hadar. Although early hominids were not nearly as efficient at habitual bipedalism as modern humans are, the basic gait of Australopithecines such as Lucy was good enough to get individuals and small groups from one resource base to the next.
This increasing complexity in terms of physical adaptation and cultural-behavior adaption are evident in the fossils and stone tools at Hadar from between six million and three hundred thousand years ago. The varying environmental conditions across this span of time in this region apparently helped select or promote certain successful adaptations to the environment. In the fossil remains of hominids at Hadar several adaptations are clearly evident, including body- and brain-size increases, evolution of more efficient parts in the skeleton for walking, and increased dexterity in the hands. In turn these adaptations were tied to behavioral adaptations, such as construction and use of stone tools, migration or patterned movements to key resources like water and food, and increasing complexity in the diets as more and more animal products supplemented a plant-based diet.
First Human and First Culture
In 1994 Hadar again made headlines. Already famous for Lucy and the First Family, researchers made a second astounding discovery: 2.3- to 2.6-million-year-old fossils of a partial Homo genus jawbone along with many teeth. These became the oldest known direct human ancestor fossils by several hundred thousand years. But that was not the end of the story. Subsequent excavations yielded over a dozen stone tools consisting of sharp-edged flakes knocked off several stone cores. Some of the flakes fit back onto the cores from which they were formed. This meant that Hadar not only yielded the oldest known remains of the human genus Homo but also the oldest human-associated tools. We might consider this a type of “First Human” and “First Culture.” In other words, if we think of culture as behavioral adaptation to the environment, then the stone tools at Hadar are the oldest known examples of human culture in the world. So hundreds of thousands of years after Lucy and First Family populations were walking across the Hadar landscape, another species associated with bipedal locomotion was also exploring and adapting to the savannah highlands and river forest lowlands at ancient Hadar. We cannot determine the exact species, but we are certain, based on the teeth and jawbone, that it is a human ancestor—a human ancestor that may have sat down among the remains of Australopithecines to craft some of the earliest tools in human history.
Stone-tool (lithic) production is usually associated with the need for a sharp cutting edge (flakes) and a heavy concussing tool (hammerstones) to not only help process food supply such as plant and animal material but also dig, defend, and attend to other purposes. We call this behavioral adaptation phase the Paleolithic Period, or “old stone age” in human history, and it is a clear sign of behavioral rather than just physical adaptation to an environment. No longer did hominids need to develop biologically sharper claws or teeth for cutting or stronger bones and muscles for concussing. Stone and other materials could be modified and utilized as tools between hominids and the environment. Behavioral adaptation had moved into the realm of tool making.
Biological adaptation now had a new and powerful partner: behavioral adaptation in both social groups and physical modification of the environment. This changed everything. The species we know as humans today is a direct result of these developments, for better or for worse. The basic stone-tool kit would be with hominids and, especially, the Homo genus for the next two million years. The combination of bipedalism, social groupings, and tools gave the Homo genus increased access and processing capabilities to varied environments and food supply. For instance, hammerstones could be used to break up carrion animal long-bones, and sharp stone knives could be used to remove soft tissue such as marrow. Indeed, East African hominid sites are full of just such evidence. Yet we know from fossilized teeth and analysis on stone tools that the human ancestral diets were omnivorous. Based on analysis of residues on the stone tools as well as C3 and C4 (carbon ratios) from human bones, this omnivorous diet consisted of an increased nutrient base that included wider varieties of flora and fauna as the transition from Australopithecines to the Homo genus line took place at Hadar and across East Africa. Hadar is well known for its fossil remains of animals such as antelope and savannah game; tools allowed for easier processing of both plants and animals and are clearly evident at later Homo genus sites.
This increased interaction with the environment in turn led to further changes toward an increasingly modern human anatomy. Brain sizes grew toward one thousand cubic centimeters, and this was only possible with a more complex, nutrient-rich diet. The Homo genus also increased their environmental ranges, albeit in haphazard growth and shrinkage patterns, across Africa and then across the globe, giving access to increased nutrient bases for brain-growth need. Modern human civilization today can be tied back to Hadar some 2.3 to 2.6 million years ago with First Human and First Culture.
Ardi
In 2009 results of finds made in the 1990s would yet again place Hadar at the center of the debate of what it is to be human. Perhaps the most important biological individual set of remains discovered at Hadar were found only forty-six miles (seventy-five kilometers) from the Lucy location. These were identified as belonging to Ardipithecus ramidus, one of the earliest known hominid species. Nicknamed “Ardi” after the genus, this individual set of female remains, though nearly as complete as Lucy, required years of preservation work before they could be studied fully in 2009. Ardi proved to be even older than Lucy and far more difficult to categorize. Ardi and her kind dated to 4.5 million years ago and earlier. She had skeletal traits associated with tree-dwelling primates as well as bipedal capabilities. The implications were astounding for paleoanthropology and human evolution: Ardi appeared to be a link between early tree-dwelling (arboreal) primates of great antiquity and the more recent habitually bipedal hominids such as Lucy and modern humans that had adapted to mixed environments of forests, waterways, and grasslands.
Various theories are posited to explain Ardi’s unique characteristics. At the heart of the issue is the cause or need for bipedalism. No doubt bipedalism frees up the hands, elevates the vision center, realigns the spinal nerve center, and, of course, allows for long-distance migrations. Increased linkages between hands, eyes, and brains also result along with increased access to a variety of nutrients and environments. But Ardi challenges the idea that bipedalism was a direct adaptation to grasslands as forests shrank due to climate changes. On one side researchers, such as Tim White, who helped discover and preserve Ardi, believe we have to rethink the so-called “savannah theory,” consisting of bipedalism emerging in adaptation to loss of forest habitat and increase of grassland habitat. White believes that ancestors of Ardipithecus are not much like chimps and monkeys of today, even though humans share 98 percent of their genetic material with chimpanzees.
An alternate theory based on Ardi’s physiology is the “food-for-sex theory.” Ardipithecus ramidus needed both arboreal and bipedal adaptations because males who accessed a broader food base from forests and grasslands successfully won out in reproduction access to females. The finding of thirty-five additional Ardipithecus ramidus remains at Hadar that are associated with the female Ardi bolster this theory. These show little sexual dimorphism (differences between males and females), as they have similar-sized, small canine teeth and similar body sizes. Such characteristics are associated with mating displays among modern primates. This could result from dual-locomotion capabilities for forests and savannahs, but it could also result from behavioral practices of social-group adaptations or perhaps a combination of the two. However, if White is correct, then Ardi and her kind have little in common with Lucy and her kind other than bipedalism. Ardipithecus has no known stone tools, lived in forested environments, and may even have had different reproduction and food gathering practices when compared to Australopithecines at Hadar, who may have had stone tools and adapted to a more mixed environment.
As with other finds at Hadar, Ardi’s kind were associated with detailed evidence of the environment in which they existed. During the time of Ardipithecus ramidus at Hadar the environment was a forested woodland rather than the dry, eroded landscape it is today. Over six thousand animal fossils were recovered from Ardi’s time. Antelope, monkey, arboreal birds, and seeds of fig and palm trees hint at the landscape that Ardi thrived in and adapted to. Wear patterns and isotope samples from Ardipithecus ramidus teeth indicate a diet of fruits, nuts, and forest foods. No stone tools were recovered in association with Ardi, and this may be key. As soon as stone tools show up in the record after Ardi’s time and toward the end of Lucy’s time, a wider diet was accessed. Fauna shows up on the menu with the arrival of tool making and usage with the later Australopithecine and Homo genus lines. Stone tools become common by the time of Homo habilis and especially Homo erectus from 1.6 million years ago. They are so plentiful that the term “Olduwan” is used to describe early humans’ use of the stone-tool set across Africa.
Such statements are only possible because of the incredible record of prehistory available at Hadar. The richness of evidence and its exposure at Hadar in particular and the Afar Triangle in general is in contrast to other hominid sites, even those in fossil East Africa and its Rift Valley, of which Hadar and Afar are a part. We currently have more Australopithecine and Ardipithecus specimens from Hadar and Afar than we do from the rest of the world combined.
First Child and Australopithecine Tools
Just recently in the new millennium yet more findings at Hadar turned the paleoanthropologist world upside down again. The discovery in 2000 by Zeresenay Alemseged of yet another Australopithecus aferensis known as the “Dikika child” sparked this upheaval. Dikika is just across the shallow riverbed from Hadar. Even for the Hadar region, this specimen was amazingly complete, with preserved skull, baby teeth, fingers, torso, a foot, and a tiny kneecap. Dated to over 3.3 million years ago, the Dikika child is fairly near the 3.18-million-year date postulated for Lucy. Some even called her Lucy’s child, though that would be a stretch. At only three years of age, the Dikika child, or “First Child” as she is now known, allows for amazing insights into the early development of infants for Australopithecines. Comparing infant growth and development among humans, chimpanzees, and ancient hominids now became possible. First Child was similar in bone growth and development to early human infants but not as similar to modern chimpanzees or, probably, prehominid fossils such as Ardi, who used both arboreal and terrestrial locomotion. Thus, early researchers may have been justified in placing Lucy, First Child, and First Family closer to other hominids than to early ancestors such as Ardi.
Another discovery associated with First Child, however, has made the bond between full hominids such as Australopithecines and the Homo genera even stronger. Researchers have long struggled with the issue of the break in the hominid line associated with diet and stone tools. Australopithecines were smaller, had no definite tools associated with them, and appeared to have eaten fewer if any large animals compared to the generally later, larger, and more omnivorous Homo genus line. Stone tools, however, were common at Homo sites and were often associated with processing food, based on common finds of animal remains with processing marks from stone tools. In 2011 near Hadar the results of analysis of two animal bones from Dikika challenged those interpretations of Homo as the only tool-making and -using genus. The bones date to a layer of deposits known to be 3.4 million years old. This was a time when only Australopithecus afarensis individuals and groups like Lucy, First Family, and First Child occupied the region. Analysis results indicate that the animal bones have cut marks from stone tools. The evidence is very similar to evidence seen for later stone-tool processing of animal bones at Homo sites. So it is possible that Australopithecines and the Homo genera were both processing animal remains for food supply. Still, the findings are preliminary, and other researchers have noted that no actual stone tools have been found and that the animal bones are several hundred feet from the nearest Australopithecine remains.
For hominid descent lines the implications would be enormous if the find stands up to scrutiny. Researchers like Donald Johanson have long suspected and speculated that Australopithecine sites likely have stone tools associated with them, but the mixed deposits and presence of later stratigraphic layers associated with the genus Homo make this difficult to prove. If Australopithecus afarensis was processing and eating large animals, this would be perhaps the final bond between Australopithecines and the overlapping but generally later-arriving Homo genus. Thus, in locomotion, diet, culture, tool use, and tool making, the two genera are much more similar than previously thought and more likely to share descent associations. This would provide an enormous step back in the human descent line and complete a major relationship in the hominid family.
Hadar and the Future
One thing is certain: Hadar will likely keep its place as the center of the debate on human origins and identity. More fossils and related environmental data are found with each expedition. Hadar is the largest outdoor classroom in existence concerning human ancestry, and its “field lab” will only get bigger. The level of preservation of individual specimens, the enormous sample size of group populations, and the equally significant environmental database make Hadar the ultimate source on all things hominid.
Even now, however, Hadar can answer certain questions. The simplistic ideas that humans and our ancestors have never physically changed or, at the opposite end of the spectrum, have changed beyond all recognition from our ancestors must be discarded. The Hadar database indicates bipedalism has been around since the time of Ardi and became more efficient through the time of Lucy into our own human genus today. Brain size increased with time, as did territorial expansion through migration. Body size, however, has oscillated, as Ardi was only 4 feet tall and Lucy 3.5 feet tall, but some of Lucy’s relatives were 5.5 feet tall. Similar variations are seen in the later Homo line. Tool making and usage indicates some of the first development of what modern humans call “culture” or behavioral adaptation. It too provides a mixed message at Hadar. We cannot be sure, but we suspect that Lucy’s genus may have been involved with stone tools based on the Dikika finds, but that Ardi and the Ardipithecine genus was not. Our human genus Homo was certainly involved, but maybe with more refined versions of stone tools than those dating from the time of Lucy.
Environment, breeding practices, behavior adaptations such as tool making, and more all combined at Hadar to leave us a complex message about the past. In addition to simplistic ideas being debunked, Hadar has done the same with idealistically driven theories about ancient life. Claims that human ancestors were somehow unique and this is what differentiated us from other living organisms do not hold up in the face of overwhelming evidence at Hadar, be they artifacts, genetic data, or skeletal remains. The record also does not substantiate theories that human ancestors were only vegetarian, strictly hunters of live game, the only tool makers and users, or the only bipedal genus. Instead, Hadar suggests a much more broad-based approach to surviving and thriving, with lots of overlap, success, and failure.
Human ancestors did not rule out anything when it came to survival and have much more in common with us today than we might at first think. Like us, they walked upright, used complex tools, sought out complex foods, and adapted to a great variety of environments. Perhaps most importantly, they survived and thrived for millions of years in East Africa and then spread across the globe as the Homo genus. Modern humans differ mainly in our attempts to settle down permanently in the last few thousand years, a process called “sedentism,” in direct contrast to the long successful “nomadic” lifestyle hominids practiced at Hadar for millions of years. It remains to be seen if we as modern humans will succeed in going against the legacy of Hadar or if we can equal the incredible Hadar hominid track record extending across seven million years of successful adaptation!
Many adaptations, many successes, and many failures are all parts of the complex story. The differences between us and our ancestors appear to be mainly in scale. Later developments, such as cooking foods to acquire higher nutrient return, help explain such differences in degree. Today modern humans with complex social networks and even more complex tool kits occupy every part of the globe. We even use complex tools to aid us in adapting to extreme environments in space and in the oceans.
Today there are over six billion humans spread across the globe, each with an average brain size of fourteen hundred cubic centimeters and an amazingly complex set of social, food, and tool-kit networks at the heart of that expansion. This expansion is one whose roots can be traced back to places like Hadar some millions of years ago. Hadar may also hold the key as to where we are headed in the future. The Hadar database is unparalleled in framing what questions we can ask—such as: What is it to be human? What was life like for our human ancestors?—and what answers we can develop concerning our past. Ardi, Lucy, First Child, First Family, and First Human have the answers, and they can be found only at Hadar, the current center of human origins and human identity, whatever that may ultimately be.
GLOBAL ENCOUNTERS AND CONNECTIONS:
Adaption, Evolution, and Migration
The world of paleoanthropologists is not a world of certainty. Most of the database concerning the human past has disappeared with the ravages of time. What is left can be interpreted in a variety of ways. Yet Hadar has forever changed the direction of those interpretations concerning early hominids. The database is too large to ignore or explain away. The time depth with associated vegetation and climate changes is too long and the fossil evidence too great not to ask questions about adaptation and evolution. We are compelled to investigate the linkages of Lucy and all hominids at Hadar.
Yet there are some questions that Hadar cannot address, at least not currently. One of those is the emergence of modern humans across the globe. For those answers, researchers are looking to southern Africa to address how and when modern humans emerged and possibly spread out of Africa. (See Chapter 2 on Makapansgat.) Sites such as those in the Makapansgat Valley in northern South Africa and Blombos Cave on the South African coast may hold the key. Just as Hadar contains an unparalleled record on early hominids, the Makapansgat Valley and its associated caves have yielded similar evidence for later hominids from the time of Australopithecines 3.5 million years ago. At Makapansgat a large database on the emergence of modern humans from a few hundred thousand years ago to the present exists. These two sites, when paired with Hadar, provide a near-continuous record of hominid evolution from 6 million years ago to modern day.
Almost a century ago early hominid researchers such as Raymond Dart began sifting through the caves and the limeworks factory at Makapansgat, as factory workers were reporting large numbers of fossils. Makapansgat possesses an excellent database on hominids and the Homo genus in Africa, and this is useful for cross-checking interpretations at Hadar. For instance, the body and brain-casing sizes of Australopithecus aferensis can be compared between Hadar and Makapansgat, as can dates of existence for genus and species up and down East Africa and the Rift Valley.
Additionally, South Africa has another site that can help fill in the gaps at Hadar concerning the emergence of anatomically modern humans a few hundred thousand years ago. This is Blombos Cave on the coast of South Africa, where evidence indicates fully modern anatomical humans were utilizing red ochre, making shell beads, and harvesting a rich variety of both marine and land animals for food supply somewhere around or just after one hundred thousand years ago. Like Hadar, the evidence from Blombos continues to grow, allowing researchers to address key questions in evolution.
For example, one of the most compelling current debates in paleoanthropology centers on whether or not early Homo genus species like Homo erectus migrated out of Africa across Eurasia between two million and one million years ago to form “pockets” of local populations that eventually evolved into modern humans. Based on the large number of Homo erectus sites around Eurasia that emerge after the development of the species in East Africa, researchers generally agree that the migrations took place. This migration or set of migrations would have been associated with sites like Hadar and Makapansgat. This is known as the original “Out of Africa” theory. A second version of the theory holds that such an early migration did occur but that a later wave of migrations of fully modern anatomical humans from around two hundred to one hundred thousand years ago replaced these early Homo populations across Eurasia. Additionally, genetic evidence suggests that modern humans emerged in East Africa between two hundred and one hundred thousand years ago. This is supported by sites in East Africa like Hadar, Makapansgat, and Blombos Cave, which all contain evidence of the emergence of modern humans in East Africa during that time span.
However, the traditional debate on the “Out of Africa” theory has recently seen another variable added. Migrations may have taken place not only by land but also by sea, as suggested by a recent discovery on Crete Island in the Mediterranean just north of Africa. Researchers have uncovered 130,000-year-old stone tools on Crete, thus indicating that modern humans had seafaring capabilities at that time. Because Blombos Cave was occupied slightly later than Crete, at around 85,000 years ago, and contains evidence of modern humans harvesting sea resources, its occupants may have also had coastal seafaring capabilities.
Adding in seafaring as an additional means of migration out of and even into Africa certainly complicates the traditional “Out of Africa” debate. It also forces researchers to rethink the roles of Hadar and Makapansgat in this debate in particular and in evolution in general. Obviously, hominids who can travel by sea might adapt differently in behavior or even in physical structure from hominids migrating by land. Or maybe not. Whatever the final conclusions from databases in East Africa and around the world, Hadar will continue to be the most important early hominid site in world history because of the quantity, quality, and continued discovery of ancient hominid fossils.
For many who enter the world of paleoanthropology and commit themselves to a life of fossil hunting as well as endless “translation” and interpretation of the past record, there comes a moment when the academic work and the fieldwork of exploration come together. For the most famous paleoanthropologist of our time, Donald Johanson, that moment came when he discovered “Lucy” in 1974. These fossilized skeletal remains were 65 percent complete, by far the most complete ever recovered for early hominids. The find captured the public’s attention, generating publicity for and interest in humans’ early ancestors.
Lucy’s Legacy, by Donald Johanson and Katy Wong
Not only did the recovery of Lucy challenge and help rewrite our interpretations of human evolution, but the fossil also indicated just how unusual and rich the fossil beds of Hadar were. The very time of hominid evolution was exposed in the sedimentary layers eroding onto the surface at Hadar between six million and three hundred years ago. The level of preservation and the quality and quantity of fossil remains both animal and hominid would prove to be unmatched anywhere else in the world. In the following primary source, Dr. Johanson vividly discusses the excitement and fortunate circumstances associated with the discovery of Lucy. As you read through the source, ponder the following questions:
•How fortunate was Donald Johanson to have found the fossils of Lucy on November 24, 1974?
•What role does “field work” play in how paleontologists interpret the past?
•Why does Lucy continue to have such an impact on how we view Africa and our concept of humanity?
Never in my wildest fantasies did I imagine that I would discover a fossil as earthshaking as Lucy. When I was a teenager, I dreamed of traveling to Africa and finding a “missing link.” Lucy is that and more: a 3.2-million-year-old skeleton who has become the spokeswoman for human evolution. She is perhaps the best known and most studied fossil hominid of the twentieth century, the benchmark by which other discoveries of human ancestors are judged.
Whenever I tell the story, I am instantly transported back to the thrilling moment when I first saw her thirty-four years ago on the sandy slopes of Hadar in Ethiopia’s Afar region. I can feel the searing, noonday sun beating down on my shoulders, the beads of sweat on my forehead, the dryness of my mouth—and then the shock of seeing a small fragment of bone lying inconspicuously on the ground. Most dedicated fossil hunters spend the majority of their lives in the field without finding anything remarkable, and there I was, a thirty-one-year-old newly minted Ph.D., staring at my childhood dream at my feet.
Sunday, November 24, 1974, began, as it usually does for me in the field, at dawn. I had slept well in my tent, with the glittering stars visible through the small screen that kept out the mosquitoes, and as sunrise announced a brilliant new day, I got up and went to the dining tent for a cup of thick, black Ethiopian coffee. Listening to the morning sounds of camp life, I planned with some disinclination the day’s activities: catching up on correspondence, fossil cataloging, and a million other tasks that had been set aside to accommodate a visit from anthropologists Richard and Mary Leakey. I looked up as Tom Gray, my grad student, appeared.
“I’m plotting the fossil localities on the Hadar map,” he said. “Can you show me Afar Locality 162, where the pig skull was found last year?”
“I have a ton of paperwork and am not sure I want to leave camp today.”
“Can you do the paperwork later?”
“Even if I start it now I’ll be doing it later,” I grumbled. But something inside—a gut sense that I had learned to heed—said I should put the paperwork aside and head to the outcrops with Tom.
A couple of geologists joined us in one of our old, dilapidated Land Rovers, and in a cloud of dust we headed out to the field. I sat in the passenger seat enjoying the passing landscape peppered with animal fossils. Flocks of quacking guinea fowl ran for cover, and a giant warthog, annoyed by our intrusion, hurried off, its tail straight up in the air. Unlike many mammals that had been hunted to extinction in the area, the Hadar warthogs were left alone by the Afar locals, whose Islamic faith forbade eating pork. Tom put the Land Rover through its paces, and as we picked up speed in the sandy washes, my mind switched gears into fossil-finding mode. After we dropped off the geologists, who needed to inspect an important geological fault that had disturbed the sedimentary layers near Locality 162, Tom and I threaded our way along smaller and smaller gullies.
“Somewhere around here,” I said. “Pull over.” Then I laughed as it occurred to me that in the remote desert you don’t have to pull over, you just stop driving. We got out and spent a few minutes locating the cairn that had been left to mark the pig skull’s locality, a little plateau of clay and silt sediments bordered by harder layers of sandstone. A year earlier, a geologist had been out on a mapping mission and the plateau was obvious on the aerial photographs we had toted along; otherwise we might have overlooked it. After carefully piercing a pinhole into the aerial photo to mark the spot and labeling it “162” on the reverse side, we lingered. I was reluctant to return to camp and my paperwork. Even though the area was known to be fossil poor, we decided to look around while we were there. But after two hours of hunting all we had to show were some unremarkable fossil antelope and horse teeth, a bit of a pig skull, and a fragment of monkey jaw.
“I’ve had it. When do we head back?” Tom said.
“Right now.” With my gaze still glued to the ground, I cut across the mid-portion of the plateau toward the Land Rover. Then a glint caught my eye, and when I turned my head I saw a two-inch-long, light brownish gray fossil fragment shaped like a wrench, which my knowledge of osteology told me instantly was part of an elbow. I knelt and picked it up for closer inspection. As I examined it, an image clicked into my brain and a subconscious template announced hominid. (The term hominid is used throughout this book to refer to the group of creatures in the human lineage since it diverged from that of chimpanzees. Some other scholars employ the word hominin in its place.) The only other thing it could have been was monkey, but it lacked the telltale flare on the back that characterizes monkey elbows. Without a doubt, this was the elbow end of a hominid ulna, the larger of the two bones in the forearm. Raising my eyes, I scanned the immediate surroundings and spotted other bone fragments of similar color—a piece of thighbone, rib fragments, segments of the backbone, and, most important, a shard of skull vault.
“Tom, look!” I showed him the ulna, then pointed at the fragments. Like me, he dropped to a crouch. With his jaw hanging open, he picked up a chunk of mandible that he wordlessly held out for me to see. “Hominid!” I gushed. “All hominid!” Our excitement mounted as we examined every splinter of bone. “I don’t believe this! Do you believe this?” we shouted over and over. Drenched in sweat, we hugged each other and whooped like madmen.
“I’m going to bring the ulna to camp,” I said. “We’ll come back for the others.” I wanted to mark the exact location of each bone fragment scattered on the landscape, but there were too many pieces and time was short.
“Good idea. Don’t lose it,” Tom joked, as I carefully wrapped the ulna in my bandanna. I decided to take a fragment of lower jaw, too, for good measure. I marked the exact spots where the bones had lain, scribbled a few words in my field notebook, and then got back into the Land Rover. . . .
[Back at the camp] I jumped out of the Land Rover and everyone followed me to the work area, where a large tent fly protected our plywood worktables. Still in a state of semidisbelief, I sat and unpacked the precious remains. Reassured that they were in fact real, I sighed with relief. Everyone leaned over to see the tiny fragments of arm and jaw. The questions came fast and furious. Is there more? Where’d you find it? How did you find it? And then there was a stunned silence as the import of what we’d found sunk in. It hit me that if I had walked just a few more paces and looked to my left rather than my right, the bones would still be there on the slope. And in the ever-changing landscape of the Afar, a single desert thunderstorm could have washed them off the plateau, over a cliff and into oblivion, forever. . . .
We celebrated the discovery with a delicious dinner of roasted goat and panfried potatoes washed down with a case of Bati beer my students had somehow managed to smuggle into camp. Conversation became less animated and more technical, focusing on morphology and size. I felt from the beginning that the fossils belonged to a single individual because there was no duplication of parts in the remains we collected; the pieces all had the same proportions and exhibited the same fossilization color. I further argued that the skeleton was a female specimen of Australopithecus—a primitive human forebear—because of the small size of the bones relative to those of other australopithecines. All australopithecines were sexually dimorphic, which is to say males and females exhibited physical differences beyond those pertaining to the sex organs. So if the lightly built ulna we discovered were from a male, then a female would have to be unbelievably tiny.
While we were all talking, Sgt. Pepper’s Lonely Hearts Club Band was playing on a small Sony tape deck. When “Lucy in the Sky with Diamonds” came on, my girlfriend Pamela Alderman, who had come to spend some time in the field with me, said, “Why don’t you call her Lucy?” I smiled politely at the suggestion, but I didn’t like it because I thought it was frivolous to refer to such an important find simply as Lucy. Nicknaming hominid fossils was not unheard of, however. Mary and Louis Leakey, giants in the field of paleoanthropology, dubbed a flattened hominid skull found in Tanzania’s Olduvai Gorge “Twiggy,” and a specimen their son Jonathan found received the moniker “Jonny’s Child.” But most of the scientists I knew wouldn’t give their fossils a cute name based on a song by the Beatles. The next morning, however, everyone wanted to know if we were going to the Lucy site. Someone asked how tall Lucy was. Another inquired how old I thought Lucy was when she died. As I sat there eating my breakfast of peanut butter and jelly on toast, I conceded that the name Lucy had a better ring to it than A.L. 288, the locality number that had been assigned to the site.
At my request, the government representative from the Antiquities Administration who had escorted our expedition sent word to the director general of the Ministry of Culture, Bekele Negussie. He arrived a few days later with some of his colleagues. While I answered their questions, I resisted referring to our australopithecine as Lucy because I was uncomfortable about an Ethiopian fossil bearing an English name. When the team returned that afternoon from the site bursting with news of more Lucy fragments, additional information about Lucy, endless speculations about Lucy, my discomfort grew. After dinner Bekele and I sat outside the dining tent looking up at a brilliant starlit sky. I talked about the implications of the discovery, how it might impact prevailing theories about hominid evolution. And we discussed arrangements for a press announcement in Addis Ababa in December.
He listened in silence, then regarded me very seriously and said, “You know, she is an Ethiopian. She needs an Ethiopian name.”
“Yes!” I agreed, relieved. “What do you suggest?”
“Dinkinesh is the perfect name for her.”
I mentally inventoried my Amharic vocabulary, which was just enough to shop for basics, greet people, ask directions, and, most important, order a cup of the best coffee in the world. The word Dinkinesh wasn’t there. “What does it mean?”
With a broad smile, as if he were naming his own child, he answered, “Dinkinesh means ‘you are marvelous.’”
He was right, it was the perfect name. Of course, today most of the world, including nearly every Ethiopian I have spoken to, calls her Lucy. And Lucy is the name that has appeared in crossword puzzles, on Jeopardy!, in cartoons, and on African Red Bush Tazo tea bags. In Ethiopia she has lent her name to numerous coffee shops, a rock band, a typing school, a fruit juice bar, and a political magazine. There is even an annual Lucy Cup soccer competition in Addis Ababa. Once, while driving through the town of Kombolcha on the way back to Addis after a field season, years after the discovery, I spotted a small sign that said LUSSY BAR. I brought the car to a screeching halt and my colleagues and I went in to have a beer. When we asked the proprietress how the place got its name, she explained in a solemn voice that many years ago a young American found a skeleton named Lucy in the Afar region, and that she took great pride in naming her bar after the fossil that proved Ethiopia’s status as the original homeland to all people. With a grin, I told her I was the American who had found Lucy. She shrieked in delight and insisted that we have our picture taken together to mount on the wall. I sent the photo to her, and for all I know, it hangs there still. But sometimes I still think of Lucy as Dinkinesh, because she truly is marvelous.
Source: Donald Johanson and Katy Wong, Lucy’s Legacy (New York: Crown-Random House, 2009), 10–11.
Johanson, Donald C., and Kate Wong. Lucy’s Legacy. New York: Crown-Random House Press, 2009.
Radosevich, Stefan, Gregory Retallack, and Maurice Taieb. “Reassessment of the Paleoenvironment and Preservation of the Hominid Fossils from Hadar, Ethiopia.” American Journal of Physical Anthropology 87 (1992):15–27.
Shreeve, Jamie. “Oldest Skeleton of Human Ancestor Found.” National Geographic. October 1, 2009. http://news.nationalgeographic.com/news/2009/10/091001-oldest-human-skeleton-ardi-missing-link-chimps-ardipithecus-ramidus.html.
Taieb, Maurice, and Donald Johanson. “Plio-Pleistocene Discoveries in Hadar, Ethiopia.”Nature 260 (1976): 293–297.
Arizona State University public workshop on Hadar/Afar Triangle paleontology sites: www.public.asu.edu/~edimaggi/Pictures/GK-12_STEM-dimaggio_compress.pdf; and Becoming Human, Institute of Human Origins, www.becominghuman.org/.
ICOMOS World Heritage Hominid Sites, www.international.icomos.org/centre_documentation/bib/worldheritage-hominidsites.pdf.
