Anthropogeny is the original study of human origins. 

During the time of Darwin, anthropogeny was the study of human origins. Then it was taken over by its sub-discipline paleoanthropology, with focus on fossils found in dry parts of Africa.

Those fossils don't tell us much about why or where humans evolved. Humans may have evolved from chimpanzees that were isolated (chimps can't swim) on a barren new volcanic island of proto-Bioko, where they could only get food by wading in seawater. 

This is the aquatic ape hypothesis, made to fit with all fossil finds, and the DNA and anatomy of humans and chimps. 

Read this popular-science article in Norwegian SciTech News: Thinking outside the box of fossils  

Or read this peer-reviewed paper in the scientific journal Ideas in Ecology and Evolution: A paradigm for the evolution of human features: apes trapped on barren volcanic islands. 

by Allan Krill, professor of geology, NTNU.   (See also AquaticApe.net)

DNA evidence shows us that the last common ancestor of gorillas and chimpanzees lived about 10 Ma ago. The two branches that diverged − gorillas (Gorilla) and chimpanzees (Pan) − look rather similar today (ape-like) because the habitats they evolved in were about the same. They did not change much from their common ancestor. 

The gorilla branch evolved in 4 different places into 4 different taxa: Gorilla gorilla gorilla, Gorilla gorilla diehli, Gorilla beringei beringei, Gorilla beringei graueri (Map of the 4 gorilla places)

About 6 Ma ago, the chimpanzee branch diverged into the chimpanzee (Pan) and human (Homo) branches. Then the chimpanzee branch evolved in 5 different places into 5 different taxa: Pan troglodytes verus, Pan troglodytes vellerosus, Pan troglodytes troglodytes, Pan troglodytes schweinfurthii, Pan paniscus (Map of the 4 chimpanzee places.) (Map of the bonobo place.)

There is no fossil record of the chimpanzee or gorilla evolution, because the places where they evolved were not suitable for fossils. The only knowledge that we have about their evolution comes from living animals and their DNA. 

Humans and chimpanzees are remarkably different, even though their DNA is quite similar. It is assumed that humans evolved to be different, because they evolved in a different habitat. Paleoanthropologists thought that this habitat was drier (e.g. savannah) than the chimpanzee habitat because fossils are found in much drier areas (East Africa, South Africa). Elaine Morgan thought that humans evolved in a wetter habitat because human features can easily be explained as aquatic adaptations (hairless body, sweat-cooling, large brain, bipedal running, babies with subcutaneous fat or blubber, protruding nose, etc.) 

There is not a single fossil that helps us understand gorilla evolution or chimpanzee evolution. Are there any fossils that help us understand human evolution? I don't think so.

There are lots of fragments of pre-human hominin taxa that are younger than about 6 Ma old. The finders want these pre-human taxa to be related to humans, but the taxa do not show progression in brain size or other human-like features. Suddenly about 300,000 years ago, we get real human fossils (Homo sapiens, Homo neanderthalensis). The pre-human taxa are not human-like, and some younger taxa seem to be throwbacks -- more ape-like than some of the older taxa. No one knows how or if they are related to each other or to modern humans.

How can we explain the origin of so many taxa, that are not showing progression toward human features? And how can we explain throwbacks to more ape-like hominins that lived during younger geologic times?

I imagine that there was a progressive increase in brain size and other aquatic human-like features on Bioko, all the way from 6 million years ago to 300,000 years ago. Homo sapiens with large brains may have existed on Bioko as early as two million years ago -- we don't know. 

During the six-million-year aquatic evolution on Bioko, many individuals were escaping to mainland Africa. When they arrived in Africa, they found fruits and other forest foods that were not available on Bioko. Their aquatic adaptations ceased, and they did not become more human-like. Their descendants later left fossils in dry areas. These are unsuccessful offshoots, whose progeny did not survive to the present.

Some of these human-like apes may have mated with forest apes, resulting in new and strange hybrid taxa with smaller brains than the apes living on Bioko at that time. Other hybrid features would also have been more ape-like than the Bioko apes. Their descendants may have evolved in various terrestrial habitats for a few million years on mainland Africa before their fossils appear in the dry areas. There are many possibilities. 

The bipedal apes with small brains and other ape-like features that are found as fossil fragments of various ages in the dry areas of Africa may all represent unsuccessful offshoots. Only the apes who remained on Bioko developed the human features, and we find their fossils on Africa and then in Eurasia, beginning around 300,000 years ago.

It has been said that those who don't know history are doomed to repeat it. The history of Piltdown Man was not well known in 1974 when the fossils of Lucy were discovered. Piltdown Man was a hoax; A knowledgeable trickster planted some bone fragments, and then took eager experts to the place where they could personally help discover them. The hoax was left unexposed for about 40 years, from 1912 to 1953, because no impartial scientists were allowed to test the bones. The Piltdown Man was a mix of bones from a human and an orangutan. When they were finally tested for fluorine absorption, the minimal amounts of fluorine that they contained showed that they did not belong to the same individual, and they were not really fossils at all.

I suspect that the same thing happened in the case of Lucy. An advanced student named Tom Gray, who knew bone anatomy and probably had access to fossil collections, led his professor Donald C. Johanson directly to the place where the Lucy fossils were found lying on the ground. They had not been found the previous year, when a fossil pig skull was found there. The Lucy fossils were lying in such a way that they could not have been there for long; Johanson wrote that "a single desert thunderstorm could have washed them off the plateau, over a cliff and into oblivion, forever."

The same day that Johanson discovered these fragments, he concluded that this was a female specimen of Australopithecus, and gave it the name Lucy. He and his team were so eager to promote their discovery, that within a few days they had notified government authorities and arranged a press conference. 

Considering human nature, it seems to me that once they had made such a sensational claim, they would not be inclined to change it or doubt it. But it should be doubted. About 40 years after its discovery, others noticed that one of Lucy's bones actually belonged to a baboon, not to a hominin. What other problems with this hominin are we not aware of? Shouldn't those bones be tested for fluorine absorption?

I have written to Johanson a few times, most recently to learn how I might get in touch with Tom Gray. Johanson has not answered my inquiries. Lucy's legacy is also part of Johanson's legacy. It is natural that he would not want to discuss these legacies with me, since it is obvious that I am trying to spoil them. 

Here you can read the beginning pages of the book Lucy's Legacy, published in 2010. 

Lucy's Legacy 

by Donald C. Johanson and Kate Wong

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 a troublesome 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 midportion 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 grey 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 they diverged from a common ancestor to the African apes. 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.

The two geologists relaxing in the shade of a small acacia tree looked relieved when we drove up to rescue them from the stultifying heat. As they stood and greeted us, they could tell from our giddy grins that we'd found something.

“Feast your eyes!” I said, and opened the bandanna. I held the ulna next to my elbow. Being geologists, they didn't know a lot about bones, but they understood the importance of the find. Back into the bandanna the bones went, and then into my khaki hat for the trip to camp in the safety of my lap. Thirty minutes later Tom announced our arrival by honking the horn, and as we pulled to a stop our inquisitive teammates surrounded the car.

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.

Suddenly someone slapped me on the back and exhilaration replaced awe. We all started talking at once, and we had to keep raising our voices to be heard so that eventually no one could hear what anyone else was saying. A hurried lunch followed and then everyone wanted to see the spot where I had found the ulna. At the locality my colleagues stood back as I carefully pointed to the bone fragments on the slope. Immediately my team understood that what they were looking at was a partial hominid skeleton. It was a special moment for all of us, though I don't think any of us truly realized how special at the time.

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.

Minibuses with no air conditioning and with an extra heater were probably made for a cold climate, not a hot one. Using similar logic, human bodies, with no fur for sun protection, and with a sweat-cooling system that uses up to a liter of salty fluid per hour, were probably not made for the hot, dry East African climate. I think the human body evolved on rainy Bioko island, off the coast of western Africa.

Icy Norwegian roads are salted in the winter, and cars here get rusty. I have a 30-year old Mercedes minibus that I use for hauling rocks and students on geological field trips. It is the fourth old minibus that I have had. When these minibuses are too rusty to last much longer, they are sent to Africa, where the rusting will cease, and they can be used for many more years as share-taxis. 

It you looked objectively at one of these rusty minibuses in Africa, you would understand that it was not in its original habitat. It might still have snow tires with the metal studs removed. You might notice its built-in heater under the back seats. It has an electric engine-warmer, so that it can be pre-warmed to start on cold winter mornings. It has insulated passenger windows, that cannot be opened on hot days. And it has no air conditioner at all.

You don't see such old minibuses here in Norway, but you might fine a few in East Africa. This is similar to gorillas and chimpanzees. You won't find fossils of them in their original habitats of central and western Africa. That is because bones decay in those habitats, and don't survive as fossils. But three chimpanzee teeth have been found in East Africa. No other fossils are known of chimpanzees or gorillas.

Human features suggest to me that human bodies were built for a place like Bioko island. It is one of the ten rainiest places on Earth, so there is plenty of fresh water and salt. The temperatures in the air and the ocean are comfortable all year round. Fur would not be needed there, because the nights are never cold, and there is no blazing sun that would burn the skin during the day. 

A dream of every paleoanthropologist is to find a fossil that "can rewrite early human evolution." A lesser goal is to find a fossil that allows a paleoanthropologist to claim a new hominin species.  A still lesser goal, but also rarely achieved, is to find a fossil fragment that can be related with any confidence to a hominin species that has already been proposed. 

The hominin species that have been proposed so far show no progression toward modern human features. And a recent survey among life scientists shows that there is no consensus as to what biological selection pressures led to the evolution of human traits. There has never been found a complete skeleton of a pre-human hominin. The skeletons that exist have been constructed, not found. They are collages that have been assembled from fragments that were collected, selected, and glued together by highly motivated and highly biased specialists. The proof that they are motivated is that they will work for years in making a collage. The proof that they are biased, is that they call themselves "paleoanthropologists" when in fact they are "paleoprimatologists."

But never mind these problems. It is fun for paleoanthropologists to find new fragments, and to play (they see it as work) with the fragments and speculations that have appeared so far. And it is fun for the educated public to try to follow along with their complicated speculations and disagreements about all the different pre-human fossil species.

Paleoanthropologists often do not agree with the interpretations of their colleagues. But they all agree that they will not discuss the possibility that humans could have evolved without fossils. That would spoil the fun for everyone!  We know that chimpanzees evolved without fossils, and gorillas evolved without fossils. For a paleoanthropologist, it is unthinkable that humans might have evolved without fossils.

If the rest of us admit the possibility that humans might have evolved without fossils, the fun discussions of human origins can be taken over by anthropogeny. In that science, one discusses not only the bones, but also the appearance, anatomy, physiology, and genetics of modern humans and chimpanzees. One speculates as to how they are related.

This would lead directly to the aquatic ape hypothesis. The fun with that hypothesis is that it can be shared by everyone, not just the fossil experts. One can have fun simply looking at the people one meets, and speculating as to why their features and behavior are similar to or different from a chimpanzee. If you see someone with a long nose, or with long oily head hair, or with a long beard on the face but no hair on the head, or a person with blubber that is perfectly appropriate for a marine mammal, you smile as you think to yourself: "There is a nice example of an aquatic ape!"

When Gray told the others about the discovery, he said "We've got it. We've got The Whole Thing." It sounds like the others knew what "Whole Thing" he was talking about. 

It is impossible for rain to uncover many deeply buried fossils all at the same time. Erosion from rain removes the top centimeter or so of sediment, which is washed down slope. It loosens a fossil fragment that is near the surface, which also moves downhill. The next time it rains, the fist piece will be washed away, and another piece will be loosened and move down hill. There are never many pieces at once.

A searcher sees a loose fragment, and then goes uphill to find more sticking out of the ground, and then digs there to find the pieces that are still buried in the sediment. But in the case of Lucy, all the pieces were found lying loose on the surface. This is impossible. Someone put them there. Rain and erosion did not do it.

https://www.google.com/books/edition/Lucy/

Lucy− The Beginnings of Humankind 

Donald C. Johanson & Maitland A. Edey

Simon & Schuster Paperbacks

1981

Prologue

As a paleoanthropologist−one who studies the fossils of human ancestors−I am superstitious. Many of us are, because the work we do depends a great deal on luck. The fossils we study are extremely rare, and quite a few distinguished paleoanthropologists have gone a lifetime without finding a single one. I am one of the more fortunate. This was only my third year in the field at Hadar, and I had already found several. I know I am lucky, and I don't try to hide it. That is why I wrote "feel good" in my diary. When I got up that morning I felt it was one of those days when you should press your luck. One of those days when something terrific might happen. 

Throughout most of that morning, nothing did. Gray and I got into one of the expedition's four Land-Rovers and slowly jounced our way to Locality 162. This was one of several hundred sites that were in the process of being plotted on a master map of the Hadar area, with detailed information about geology and fossils being entered on it as fast as it was obtained. Although the spot we were headed for was only about four miles from camp, it took us half an hour to get there because of the rough terrain. When we arrived it was already beginning to get hot. 

At Hadar, which is a wasteland of bare rock, gravel and sand, the fossils that one finds are almost all exposed on the surface of the ground. Hadar is in the center of the Afar desert, an ancient lake bed now dry and filled with sediments that record the history of past geological events. You can trace volcanic-ash fall there, deposits of mud and silt washed down from distant mountains, episodes of volcanic dust, more mud, and so on. Those events reveal themselves like layers in a slice of cake in the gullies of new young rivers that recently have cut through the lake bed here and there. It seldom rains at Hadar, but when it does it comes in an overpowering gush−six months' worth overnight. The soil, which is bare of vegetation, cannot hold all that water. It roars down the gullies, cutting back their sides and bringing more fossils into view. 

Gray and I parked the Land-Rover on the slope of one of those gullies. We were careful to face it in such a way that the canvas water bag that was hanging from the side mirror was in the shade. Gray plotted the locality on the map. Then we got out and began doing what most members of the expedition spent a great deal of their time doing: we began surveying, walking slowly about, looking for exposed fossils. 

Some people are good at finding fossils. Others are hopelessly bad at it. It's a matter of practice, of training your eye to see what you need to see. I will never be as good as some of the Afar people. They spend all their time wandering around in the rocks and sand. They have to be sharp-eyed; their lives depend on it. Anything the least bit unusual they notice. One quick educated look at all those stones and pebbles, and they'll spot a couple of things a person not acquainted with the desert would miss. 

Tom and I surveyed for a couple of hours. It was now close to noon and the temperature was approaching 110. We hadn't found much: a few teeth of the small extinct horse Hipparion; part of the skull of an extinct pig; some antelope molars; a bit of a monkey jaw. We had large collections of all these things already, but Tom insisted on taking these also as added pieces in the overall jigsaw puzzle of what went where. 

"I've had it," said Tom. "When do we head back to camp?"

"Right now. But let's go bak this way and survey the bottom of that little gully over there."

The gully in question was just over the crest of the rise where we had been working all morning. It had been thoroughly checked out at least twice before by other workers, who had found nothing interesting. Nevertheless, conscious of the "lucky" feeling that had been with me since I woke, I decided to make that small final detour. There was virtually no bone in the gully. But as we turned to leave, I noticed something lying on the ground partway up the slope.

"That's a bit of a hominid arm," I said. 

"Can't be. It's too small. Has to be a monkey of some kind."

We knelt to examine it. 

"Much too small," said Gray again. 

I shook my head. "Hominid."

"What makes you so sure?" he said.

"That piece right next to your hand. That's hominid too."

"Jesus Christ," said Gray. He picked it up. It was the back of a small skull. A few feet away was part of a femur: a thighbone. "Jesus Christ," he said again. We stood up, and began to see other bits of bone on the slope: a couple of vertebrae, part of a pelvis−all of them hominid. An unbelievable, impermissible thought flickered through my mind. Suppose all these fitted together? Could they be parts of a single, extremely primitive skeleton? No such skeleton had ever been found−anywhere.

"Look at that," said Gray. "Ribs."

A single individual?

"I can't believe it," I said. "I just can't believe it."

"By God, you'd better believe it!" shouted Gray. "Here it is. Right here!" His voice went up into a howl. I joined him. In that 110 degree heat we were jumping up and down. With nobody to share our feelings, we hugged each other, sweaty and smelly, howling and hugging in the heat-shimmering gravel, the small brown remains of what now seemed almost certain to be parts of a single hominid skeleton lying all around us. 

"We've got to stop jumping around," I finally said. "We may step on something. Also, we've got to make sure." 

"Aren't you sure, for Christ's sake?"

"I mean, suppose we find two left legs. There may be several individuals here, all mixed up. Let's play it cool until we can come back and make absolutely sure that it all fits together."

We collected a couple pieces of jaw, marked the spot exactly and got into the blistering Land-Rover for the run back to camp. On the way we picked up two expedition geologists who were loaded down with rock samples they had been gathering. 

"Something big," Gray kept saying to them. "Something big. Something big." 

"Cool it," I said. 

But about a quarter of a mile from camp, Gray could not cool it. He pressed his thumb on the Land-Rover's horn, and the long blast brought a scurry of scientists who had been bathing in the river. "We've got it," he yelled. "Oh, Jesus, we've got it. We've got The Whole Thing!"

That afternoon everyone in camp was at the gully, sectioning off the site and preparing for a massive collecting job that ultimately took three weeks. When it was done, we had recovered several hundred pieces of bone (many of them fragments) representing about forty percent of the skeleton of a single individual. Tom's and my original hunch had been right. There was no bone duplication. 

But a single individual of what? On preliminary examination it was very hard to say, for nothing quite like it had ever been discovered. The camp was rocking with excitement. That first night we never went to bed at all. We talked and talked. We drank beer after beer. There was a tape recorder in the camp, and a tape of the Beatles song "Lucy in the Sky with Diamonds" went belting out into the night sky, and was played at full volume over and over again out of sheer exuberance. At some point during that unforgettable evening−I no longer remember exactly when−the new fossil picked up the name of Lucy, and has been so known ever since, although its proper name−its acquisition number in the Hadar collection−is AL 288-1

Bones from a single animal lie buried within a single horizontal layer of sediment. A few million years later, erosion  starts to expose the layer. Gullies are carved into the soft sediment, and part of the layer is exposed in the slope of the hill. Each time there is a hard rain, a centimeter or more of sediment can be loosened from the edge of the slope, and washed downhill. This rain can free a fragment of one of the bones, which also moves down the hill, and can be found loose on the ground.

The fossil hunter finds such a loose fragment, and then goes directly uphill looking for the place where it weathered out of the ground. When he finds that place, he digs and gets more of that bone and other bones of the same animal in the same layer. 

If no one finds the fragment that is washed down the hill, it will be washed away in the next rain. Then another fragment will come out of the layer. Only a few fragments can occur loose on the surface at any one time. Earlier fragments have washed away, and the rest of that bone and other bones are still buried in the layer of sediment. It is impossible that most bones of a million-year-old skeleton will be exposed and lying on the surface at the same time.

On the morning of November 24, 1974, Tom Gray led his eager professor Donald Johanson directly to the place where all the Lucy bones were lying loose on the surface.  Nothing more was found in the ground. Those bones could not have been lying there for more than a year or so. Johanson explained this in his book Lucy's Legacy in 2010. He wrote that the fossils were lying in such a way that "a single desert thunderstorm could have washed them off the plateau, over a cliff and into oblivion, forever."

I think that Gray knew those fossils were lying there at Hadar Location 162, where the same team had searched in 1973. Maybe Gray did not know exactly where the fossils would be, or if they would still be there when they arrived that morning. In his first book (Lucy − The Beginnings of Humankind, 1981) Johanson reported that when they returned to camp after finding the Lucy fossils, this is how Gray told the others:  “We’ve got it,” he yelled. “Oh, Jesus, we’ve got it. We’ve got The Whole Thing!” 

I have done a lot of fossil collecting in such erosional areas, and know how it works. In the soft eroded hills of France, there are many fossils of all kinds. After a hard rain, hobby collectors go to their favorite places on a Sunday afternoon, and pick up the newly exposed fossils − things like small ammonites, brachiopods, snails, corals, and even dinosaur eggshell fragments and dinosaur bone fragments. If one does not pick them up after a hard rainstorm, they will be washed away in the next hard rainstorm.

The problem with these arguments is that molecular evolution is not the same as phenotypic change. And even in closely related species, rates of morphological or behavioral change can differ substantially over time. Darwin was aware of this latter point, as illustrated by the quotation that opens this chapter. Pilbeam and Lieberman (this volume) observe that multiple primate lineages are morphologically conservative over extended periods of evolutionary time. The gibbon (Hylobatidae) radiation, for example, has been dated to around 7 Ma, putting it close in time to the Pan / Homo divergence (Israfil et al. 2011). Few would contend, however, that the common ancestor of the fourteen-plus gibbon species alive today looked very different from a modern gibbon, on the basis that gibbons have been “evolving for as long as humans and gorillas.”3 

The inference that chimpanzees are also a conservative species, little changed since their split from the hominin line, is based on careful analysis and straightforward logic (Pilbeam 1996; Wrangham and Pilbeam 2001; Pilbeam and Young 2004). Chimpanzees and gorillas are extremely similar morphologically, to such an extent that for decades they were considered to be monophyletic, fundamentally size variants of the same animal. Genetic data, however, are unambiguous in showing that chimpanzees and humans are more closely related to each other than either is to the gorilla. This points to one of two conclusions: the extensive similarities between chimpanzees and gorillas represent evolutionary convergence, or the last common ancestor of chimpanzees, gorillas, and humans was very much like a chimpanzee or a gorilla. Because such extensive convergence is unlikely, and because the earliest hominins are all chimpanzee-sized, the LCA is inferred to be chimpanzee-like. 

Java Man
Eugène Dubois was a Dutch anatomist and fossil collector. He was the first person to present missing-link fossils that are currently accepted by scientists. Arthur Keith, who had studied Piltdown Man (see below) discussed Dubois and his finds in considerable detail. In 1925 he wrote (9, p.438):

Having finished a training in science and medicine at the University of Amsterdam in 1888, he became a military surgeon, choosing Java for his service. Before setting out for that island, he promised his fellow-students, in all seriousness, to bring home the "missing link." And he made his boast good, for in 1894 he returned with the fossil remains described in the previous chapter. But he also had in his possession then certain other fossil remains of man, of which, for reasons of his own, he said nothing, until May 1920—twenty-six years after his return from Java.

The fossils that Dubois brought back as his missing link were a skullcap, three teeth in a jaw fragment, and a thigh bone. They were found by his workers, and not found together. 

Nearly all anatomists have agreed that the thigh bone looks like that of a modern human. Curiously, it had been broken and healed while the person was still alive. The jaw fragment, as well as two of the three teeth, were more or less ignored and are now mostly forgotten. Keith (9, p. 439-440) explained that in 1890, the year before those fossils were found, Dubois had collected many fossil bones of modern humans in a nearby Java locality. Those bones were preserved in volcanic ash deposited in a lake, together with bones of animals and mussels. Dubois also had access to other bones in Java. A modern chimpanzee skull was sent to him from Berlin (10, p.56). After returning to Amsterdam, Dubois locked up his missing-link fossils for twenty years, and would not allow other scientists to study them. He mislead scientists in many ways, but the hypothesis of outright hoax has never been considered. His missing-link fossils have not been chemically tested.


Peking Man
Davidson Black was an ambitious Canadian physician and anatomist. He spent part of 1914 at the laboratory in England where the Piltdown Man had been studied. He did not have access to those materials, as they were kept hidden from visiting scientists. He must have been impressed with the international attention given to such fossils.

Black determined to find his own missing link, and in 1919 he went to China to do so. A few years later, two human-like teeth and some chipped stones were found in a cave with other animal bones. Black announced these to be a missing link, and used this evidence for all it was worth. The missing link became known as Peking Man. In 1926, he began receiving generous funding for excavations of the cave. More human-like bones were then found.

Black died suddenly in 1934 at the age of 49. Detailed descriptions of the bones were then published by his successor Franz Weidenreich (14). He concluded that these and the Java fossils were from a race of fully evolved human, like Neanderthal Man. Furthermore, Weidenreich (14, p. 216) was convinced that Piltdown Man was an error, being the skull of a human and the jaw of an orangutan. It may have been his published skepticism that pressured scientists to allow the chemical testing of the Piltdown fossils.

In 1941, all the fossils of Peking Man were mysteriously lost and have never been found. There is no material that is available for chemical testing or dating. Today, Java Man and Peking are generally assigned to the missing-link species Homo erectus.

Hey Chimps!  Sail on over to Bioko!
It's less than 50 km away — a quick trip (if you're lucky) 

You won't be able to leave, and your descendants won't want to leave. 

Relax with plenty of nutritious marine food — great for brain growth. 

No need to look for food in the forest. (In fact, there is no forest.)

You won't need big jaws. The shellfish and marine greens are chewy. 

You'll be the only large animal around!   No leopards. No crocodiles. Always safe.

Bathe completely naked — throw away that wet fur coat forever!
Nights are warm. It's almost always cloudy, so no strong sun to burn your skin.
Learn to swim! Learn to hold your breath in water!   It's not as hard as you think.
Control your breath, then learn how to talk!  Be able to talk with family and friends.

Have sex in the water with the mate of your choice!   No alpha males here.
Males — you won't need those sharp canine teeth to compete!
Females — Your babies will be born with blubber!
Give birth in the water, and let your plump baby float while you are eating or sleeping.
No predators to come and snatch your crying babies.

No nasty African viruses! No need to carry water — it's nearly always raining.

Pull off an "Evolutionary Bio-Coup"— sail to Bio-ko.
(Your descendants might take over the planet!)

In the water you'll get food to eat. 
Won't have to hang in the jungle. 
Won't need to compete. 
You'll eat crab and clam, so your brain gets big. 
You're all gonna be the new Sapiens. 

Ain't no lion or leopard. Ain't no crocodile. 
You got no one to fight, you'll get teeth to smile. 
Ev'rybody be happy like no chimp can be. 
So hold on to that raft. Sail across the sea. 

Sail away. Sail away. 
You will cross the 30 miles of Bioko Bay. 
Sail away. Sail away. 
You will cross the 30 miles of Bioko Bay. 

In the water all the food is free. 
Just take care of yourself and your family. 
You'll get naked and fat like no chimp can be. 
You're all gonna be the new Sapiens. 

Sail away. Sail away. 
You will cross the 30 miles of Bioko Bay. 
Sail away. Sail away. 
You will cross the 30 miles of Bioko Bay.