(01) NOVA | Transcripts | In Search of Human...(01) NOVA | Transcripts | In Search of Human Origins taken it up themselves to guard us personally, because this is also bandit country

(01) NOVA | Transcripts | In Search of HumanOrigins

PBS Airdate: June 3, 1997

ANNOUNCER: Tonight on NOVA, a tinyfemale collapses into an ancient lake. She emergesthree million years later, and a determinedanthropologist finds her fossilized bones. Couldshe be the missing link between ape and us? ForDon Johanson, she is the starting point of atireless quest to understand our past. "In Searchof Human Origins."

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http://www.pbs.org/wgbh/nova/transcripts/2106hum1.html



DON JOHANSON: In the remote past, more than three million years ago, a tiny femalelived by a lake on the edge of the lush forests of Africa. She was part ape, part human. Shelived a brief life, but her story continues to unfold. By an extraordinary set ofcircumstances, she left tantalizing clues to her life and our origins. Who was she and whatcan we discover about this earliest of our most ancient ancestors? We know she existedbecause we found these, her fossilized bones, in the very spot where she died all those yearsago. Fossils like these are so rare, that they're even harder to find than diamonds, but they'rethe key to understanding our origins, knowing who our ancestors were, and how theylived. The human story begins in one of the most geologically fascinating places on theplanet, the Great Rift Valley of Africa. It's an enormous split torn in the Earth's crust thatruns from the forests of Tanzania to the deserts of Ethiopia. In some places, the rift isthousands of feet deep and exposes the last fifteen million years of the Earth's history.

I'm Don Johanson and over the last twenty years, I've been leading fossil huntingexpeditions in this remote part of Africa on the trail of our earliest ancestors. The journeytakes me and my team right down to the floor of the Great Rift. It takes two days drivingdawn to dusk, if our vehicles don't break down. But it's only in places like this where thefossils we're looking for can be found. People often ask why we look in Africa for remainsof our earliest ancestors. Well, Charles Darwin had a pretty good answer to that questionover a century ago. When he observed the close similarities between humans and modernAfrican apes, he correctly concluded that we must have shared a common ancestor.Starting with the modern human skull, we can trace our ancestry back millions of years.And as we travel back in time, our ancestors look less and less like us. They begin toresemble our closest relatives, the African apes with their small brains. Fossil skulls likethese help us unlock the mystery of our past. And it is in Africa that the earliest humanfossils are found. Our team always camps here, at a place called Hadar, in Ethiopia, on thebanks of the Awash River. The river is our lifeline in this otherwise waterless place. Aftertwo days of bumping along dusty roads, there's a welcome peacefulness about the camp.The days quickly settle into the rhythm of expedition life. The local people are nomadictribesman called the Afar. We've known them twenty years. This is their land and theyallow us to come here and help us in our search. Ever since I first came to Hadar, they've




taken it up themselves to guard us personally, because this is also bandit country. It's notthe most comfortable place to work, but if you're a fossil hunter like myself, it's a dreamcome true. When I first came to Hadar, I realized that this was exactly the place I waslooking for. It's potential is absolutely staggering. When I began to walk these gullies andvalleys, I saw tons of fossils eroding out of these ancient geological strata. There's almost novegetation, so the seasonal rains do most of the work for us, scouring the surface,uncovering buried fossils. There are bones of every imaginable creature, perfectlypreserved in stone. But even here, human remains are incredibly rare. That's because thejourney from a living creature to a fossilized bone only happens under the most unusualconditions. I can make a good guess about how our earliest ancestor might have beenpreserved millions of years ago. She wasn't killed by a predator, she died a natural death.Undiscovered by scavengers, her body simply sank into the soft sediments of the lake.There, lying undisturbed, her flesh slowly rotted away. Sand and gravel washed in by heavyrains gradually covered the bones. Over the millennia, hundreds of feet of sediments builtup, burying the bones deeper and deeper.

Minerals from the sediments gradually replaced the calcium of her bones, almost moleculeby molecule, turning them to stone. Over the next few million years, she remained buried,but the movement of the Earth's crust, continuing to enlarge the Great Rift, brought herancient grave closer to the surface. There she lay until rains cut down through the Earth,and one heavy storm brought her to light again. Spotting such rare human fossils doesn'thappen often. But we can discover a great deal about our ancestors' world by looking forthe more plentiful remains of the animals that lived with them. As soon as we're settled in,everyone is eager to see what this year's rains have washed out onto the surface. We're ateam of Ethiopian and American scientists, and with us, some of the sharpest-eyed fossil-finders of all: the local Afar people. There's really no other way to find fossils, except towalk these exposures day-in, day-out, hoping to find something interesting. Here, forexample, there's just a canine of a hippo, and a very beautifully preserved molar of a giraffe.It's interesting that virtually every animal has its own diagnostic anatomy, it's owndiagnostic features, so even from a single tooth like this, we can tell what kind of a creatureit was, a good specimen that we'll catalogue and bring back to camp. But how couldhippos and




giraffes live in this harsh desert? It must have been a very different place three million yearsago. All told, we've collected more than ten thousand specimens from over a hundredspecies, everything from rodents to elephants. The clues to their lost world lies scattered allover the ground. Although it's a seemingly uninteresting piece of bone, if you look atdetails, you begin to see a number of clues. For example, the shape of the tooth indicatesthat it was probably from a pig, part of a lower jaw. But even more intriguing is a series ofindentations on the inside of the jaw. And if we look at them with a hand lens like this, it'sobvious that that bone was pushed in when it was fresh, and it's very likely that this pig,three million years ago, had wandered down to, say the edge of a river, and became dinnerfor some lucky crocodile. A picture of our ancestors' world vanished world is beginning toemerge. Here's more of this elephant tusk that's eroded out down this slope, and here areboth tusks of the elephant. And here are the upper molars. By keeping track of every fossilwe find, we can map out a world totally different from Hadar today. The geologists canhelp us, too. They sample ancient layers of the Earth that have been exposed in the GreatRift Valley. Geologist, Tesfaye Yemani, has discovered that Hadar was wet and forestedmillions of years ago.

TESFAYE YEMANI: This is a landsat image of the Hadar area, and then as you can see,there are several dry river coming from the western mountain of Ethiopia, flowing toAwash River. The same thing was happening during the time of between four and threemillion years ago, except this, the river were flowing through very thick forests and not adesert like today.

DON JOHANSON: At the time of our earliest ancestors, this place was lush and green.Back then, there were rivers and lakes with communities of animals living in and beside thewater. Here were the pigs and the elephants whose fossils we found. Deep in the forestlived the apes from which we and chimpanzees are descended. The lives of today'schimpanzees hint at our close kinship with the apes. Even though they have smaller brainsthan we do, chimpanzees have many human characteristics. They're highly social, theyhave a sort of language, and they use tools. In the distant past, we shared a commonancestor with these




chimps, so our earliest ancestor must have been part ape, part human. For well over acentury, people have been fascinated by the search to find the missing link, a creature thatwould bridge the gap between ourselves and the primitive apes. It was always thought thatthe key feature that separates us from the apes is intelligence. It was logical to think, then,that the earliest ancestors would have large brains. The argument goes like this: thechimpanzee skull holds a brain three times smaller than modern man. If increase in brainsize set us on the path from ape to human, it was thought that the missing link should havefirst developed a big human-like brain. Back in the heat of Hadar, following the trail of themissing link is grueling work. The sun pushes the temperature to over a hundred degrees.But there's always an air of anticipation, because you never know what might be in thenext ravine. This is a fossil-finder's dream: a perfectly complete skull partly concealedbeneath a covering a sandstone. But it's not one of our ancestors, it's a baboon, a kind ofmonkey. In a century of fossil hunting, skulls have always been the prize. After all, if ourearliest ancestor were a large brained ape, a skull would be the perfect proof. But the storyis like a detective thriller, full of false trails, never straightforward, and it can all changeunexpectedly, because from time to time a fossil is found that is so different that it entirelyturns the story of our origins upside-down. The trail began not with the skull, butwith something totally unexpected. I was surveying late one afternoon when we were outcollecting some elephant teeth, and I looked down on the ground and found in a couple ofpieces this knee joint. At first, I thought it was just from a monkey, maybe a baboon, but itwent together in a way that didn't look like any monkey. If it wasn't a monkey's knee whatwas it? It looked vaguely human, but how could that be? I needed an expert opinion.Owen Lovejoy is an anatomist, part-time forensic scientist and an expert on animallocomotion. If anyone could tell me what sort of creature that knee belonged to, he could.

OWEN LOVEJOY: When Don brought the Hadar knee back from Ethiopia, he brought itover to my house and laid it out on the living room carpet, and I knew instantly, that was ahuman knee.




DON JOHANSON: My suspicions were confirmed. As Lovejoy pointed out, the jointhad all the hallmarks of a creature that moved around on two legs, not on all fours.Walking upright is something that only humans can do. And it needs a special kind of kneejoint, one that can be locked straight. A chimp gets around on all fours. If it tries to walkupright, it's knee joint doesn't lock. It's forced to walk with a bent leg and that's tiring. Thismysterious fossil really perplexed us. What was a modern-looking human knee doingamong fossils that were millions of years old. We had to find out how old that knee reallywas. The hills at Hadar contain distinct layers of light colored volcanic ash. We can't datefossils directly, but we can date the ash. And once we know how old the ash is, we knowthat any fossil found beneath it is at least that old. With the eye of a connoisseur, thegeologists select the best ash samples for analysis back in the lab. Dating techniques are soprecise that we only need small samples, as little as one single crystal or grain. The purestcrystals are blasted by an Argon laser we've nicknamed Flash Gordon. As it melts, thecrystal releases Argon gas. The amount of gas given off gives us a direct estimate of the ageof the volcanic ash, and once we know that, we could work out the age of any fossil wefound nearby. The results were exactly what we had hoped for. The knee was over threemillion years old, one of the oldest human fossils ever found. I felt sure we were ontosomething completely new, yet the knee posed troubling questions. What sort of ancientcreature would have a modern knee? I kept turning it over and over in my mind. What didit mean?

We needed more fossils and luckily the knee generated such scientific interest that we hadno trouble mounting another expedition. And the next year we were back once more atHadar. On every expedition, breakfast is the time we spend planning the day's work. Onemorning, two of us decided to go back to a gully that we hadn't finished working on theday before. Fossil hunters sometimes rely on hunches, and that morning, I had a hunchthat this would be my lucky day. I was headed back to my land rover, it was about noontime, and I was going to drive back to camp. And I just happened to look over my rightshoulder,




and I noticed a small piece of bone resting on the surface of the ground, and as I began tolook around and scanned the slope, I could see not only bits of a leg, but bits of a skull, alittle piece of a jaw, and I realized right there in that noon day sun that what I had literallystumbled across was most of an entire skeleton. In ancient times a creature died Now afterthree million years, her bones had come to light. A skeleton as old as this had never beenfound before. As more and more of these precious fragments came back from the field, abuzz of excitement ran through the camp. Everyone knew instinctively this was somethingbig.

TESFAYE YEMANI: To find such a fossil was wonderful for me, you know. It was a nightI'll never forget. And it was wonderful for Ethiopia, too. After this, everybody wanted tocome here to look at our Lucy.

DON JOHANSON: The shape of the lower jaw and tiny details of the teeth alerted us toan intriguing mixture of ape and human-like features, something we'd never seen before.Some of the fragments were tiny, hundreds of them were collected, carefully cleaned andlaid out on the table. The whole camp was absorbed with the mystery of what this creaturelooked like. The pelvis was in fragments. It took hours to piece it together.

TESFAYE YEMANI: In Ethiopia, you know, we called her Dinkanesh. It means "thing ofwonder."

DON JOHANSON: The hours passed. No one thought of sleep, we had so much to do.Then we looked at the knee. It was modern, human-like, just like the one I'd found theprevious year. As we put the bones together, we saw they came from one tiny adult female,standing only three and a half feet tall. This was the creature we'd been looking for. Thecelebration began. One song was placed over and over, and we named our new find Lucy.Lucy became an almost instant celebrity in anthropological circles. She didn't look likeanything we had ever found before. She was something very different. And because ofthat, she opened up for us an entire new chapter on human origins. Lucy turned oldpredictions upside-down. It was thought the missing link would be a smart ape that walkedon all fours. Here was the skeleton of a creature that looked like it could walk like us butwith many ape-like features. The ape that stood up, it was a revolutionary idea.




We needed Owen Lovejoy's expertise again, because the evidence wasn't quite adding up.The knee looked human, but the shape of her hip didn't. Superficially, her hip resembled achimpanzee's, which meant that Lucy couldn't possibly have walked like a modern human.But Lovejoy noticed something odd about the way the bones had been fossilized.

OWEN LOVEJOY: When I put the two parts of the pelvis together that we had, this partof the pelvis has pressed so hard and so completely into this one, that it caused it to bebroken into a series of individual pieces, which were then fused together in laterfossilization.DON JOHANSON: After Lucy died, some of her bones lying in the mud must have beencrushed or broken, perhaps by animals browsing at the lake shore.

OWEN LOVEJOY: This has caused the two bones in fact to fit together so well that they'rein an anatomically impossible position.

DON JOHANSON: The perfect fit was an allusion that made Lucy's hip bones seems toflair out like a chimps. But all was not lost. Lovejoy decided he could restore the pelvis toits natural shape. He didn't want to tamper with the original, so he made a copy in plaster.He cut the damaged pieces out and put them back together the way they were before Lucydied. It was a tricky job, but after taking the kink out of the pelvis, it all fit togetherperfectly, like a three-dimensional jigsaw puzzle. As a result, the angle of the hip looksnothing like a chimps, but a lot like ours. Anatomically at least, Lucy could stand like ahuman. The case for our earliest ancestor walking upright was growing stronger, andLucy wasn't the only evidence. Around the same time, another remarkable fossil wasfound by a team working in Tanzania led by Mary Leakey. It was a mysterious footprint.Three and a half million years ago, a volcano erupted a thousand miles from Hadar near aplace called Laetoli in Tanzania. Over the weeks, it threw tons of ash into the air thatrepeatedly blanketed the landscape. By a stroke of good fortune, the eruption took place atthe beginning of the rainy season. As the rain set in, the ash became muddy and coveredwith animal prints. A bird picked its way across the ground, followed by a scurryingAfrican




hare. Then as time passed, another creature arrived that left prints we would all recognize.Eventually, all these prints were covered by ash from another eruption and preservedforever as they hardened into rock. Three and a half million years later, Mary Leakey'sexpedition uncovered this trail. There were footprints from at least two individuals,apparently walking side by side. The unusual chemistry of the volcanic ash was like plaster,preserving the prints as a series of detailed molds and casts in solid rock. Evidence like thiswould delight a forensic scientist like Owen Lovejoy. The analysis of footprints from acrime scene can be vital in identifying a suspect. How different were those ancientfootprints in Laetoli from ones like these?

OWEN LOVEJOY: There's no better evidence than that provided by a footprint. That'swhat makes the Laetoli prints so exciting, because they give us a direct record of how ourancestors walked almost four million years ago. When we compare the Laetoli print to thatof a chimpanzee, the difference is immediately obvious. The chimpanzee, which is aquadruped, but occasionally a biped, still has a free great toe, and that great toe extends outaway from the foot and leaves a very distinct mark. On the other hand, when we comparethe Laetoli print to that of a crime scene human print, they're virtually indistinguishable.The great toe is in line with the rest of the toes. And what this has done in the human andthe Laetoli print is to create an arch. And that's a hallmark of typical modern uprightlocomotion, because the arch is an energy absorber. And that's the kind of fine tuning thatyou would expect in a biped that had been that way for a very long period of time.

DON JOHANSON: So a picture of Lucy and her kind begins to emerge. They werestrong walkers. Like us, they could keep going all day long, probably in search of food. Buthow human-like were they in other ways? Had they begun to develop a human-size brainto go with their human walk? Lucy couldn't help us there. Her skull was almost entirelymissing. So knowing the exact size of Lucy's brain was the crucial bit of missing evidence.But from the few skull fragments we had, it looked surprisingly small. What we needed wasa complete skull. Finding one has always been our goal. On the second day of thisexpedition, I'd gone out to search a remote part of the valley alone when I foundtantalizing fragments of a skeleton. I rushed back to camp and alerted the team. Wedecided to drop everything,




pack our gear and set out on the dusty drive to search for more. I was sure that the bonefragments I'd found, a piece of skull, an arm bone, and some finger bones, belonged to ahuman ancestor. Fragments found together like this are so rare that we needed everyone'shelp. We were excited, but tense. Would we find the rest of this ancestor? When wearrived, we mapped out the area where I'd found the small piece of arm bone, and a tinyfragment of skull that were freshly broken. That meant they hadn't been on the surfacelong. There was a chance that the rest of the arm bone, and maybe even more of the skull,were still buried in the hillside. Because they're so delicate, complete skulls hardly eversurvive. The dig had to be conducted with meticulous care. The stakes were high. Wehoped we were about to uncover another Lucy, maybe even more complete. The workrequires extraordinary concentration. We hardly exchange a word. There's a lot of groundto cover, but we try to make sure nothing escapes our attention. All the spoil is screenedwith an expert eye to double check for any minuscule fragments, but it's mostly just dirt.After a week of painstaking and exhausting digging, we hadn't found anything. Ourinitial optimism was flagging. Where were the bones? Because if the skull had eroded out,it goes into so many pieces, and we've not found a single fragment of it. I mean not—nothing. Setbacks and fruitless days are all part and parcel of an excavation. All we can do isreturn each day and keep searching. After a week, we sent part of the team off to search inanother location, but a few of us stayed on. Any fragment raises our hopes because itmay be part of the puzzle. Another week passed, and we'd found a few fragments, but nosign of any skull. But on an expedition, you can never be sure what will happen next Iclearly remember that evening. At dusk, I returned to camp. The moment I arrived, Icould tell that something was up. The team we'd sent off had returned to camp with a bagof bones.

To the expert eye, those fragments were clearly part of a skull. We'd found it at last, theprize fossil, a skull from Lucy's kind. In the afternoon, when it's too hot to dig, BillKimbel, a resident anatomist, began to put the pieces together.




BILL KIMBEL: The world has been waiting for a complete skull of Lucy's species for along, long time. And it's going to take a great deal of work to assemble it, to see what thebrain size might be, what the relationships might be between the various components ofthe skull, but even already, we can see that as we assemble larger pieces from smaller pieces,joining them together, we're beginning to get a fairly impressive picture of a species thathas a very ape-like face with big protruding brow ridges, very ape-like.

DON JOHANSON: We think Lucy's skull might have looked something like this, with areceding forehead and a prominent face. And with a brain case no larger than a chimps,this was no smart ape. That skull tells us for certain that our earliest known ancestor was asmall-brained creature, capable of walking upright, much like modern humans. It tells usthat our ancestors first stood up, and only got smart later. But why was walkingso important in our evolution? In order to understand that, we have to learn more abouthow Lucy and her kind made a living three million years ago. Even before Lucy's time, theclimate of tropical Africa was changing. There were alternating seasons, wet and dryand less rainfall overall. The dense forests were beginning to shrink. East of the Great Rift,the forests were replaced by open grasslands with scattered clumps of trees. Under thesenew conditions, some species died out entirely, and others took their place.

New species of antelope were colonizing the forest edges. High in the trees, the ancestors oftoday's monkeys were on the increase. The monkeys' strategy is to produce a lot of youngquickly. Their populations expanded rapidly at the expense of the apes, who reproducedmuch more slowly. Before long, the apes were in retreat, pushed out by the monkeys. Thenumber of apes declined along with the shrinking forests. Except, that is, for one: Lucy, theape that stood up. How did her upright stance, her ability to walk on two legs help Lucyand her kind compete in a new and changing world? Lucy probably became a walker whilestill very much dependant on the forest for food. But when the forest became sparse andtimes got tough, Lucy and her kind could still survive by walking across the grasslandsto reach the clumps of trees where her food was found. And her hands were free to collectand carry the valuable food she found. This slight advantage was all she needed. While the


https://www.sciencedaily.com/releases/2010/08/100817122405.htm


other apes declined, Lucy and her kind flourished. But how did this way of life effect therest of Lucy's day to day existence? Can fossils give us any insight into her behavior? Backat the excavation, weeks of hard work and hundred degree temperatures were finallyproducing results. We unearthed some pieces that looked like an arm bone, the ulna, thebone between the elbow and wrist. We'd never found a complete one before.

BILL KIMBEL: I think it looks—looks good for finding more of it.

DON JOHANSON: You know, I think there's no questions that this is just an ulna. Seethis groove here? Look.

BILL KIMBEL: Is the styloid there?

DON JOHANSON: I think the styloid process is preserved.

BILL KIMBEL: Terrific. I wonder if we're going to get a fit between this piece here andthis piece?

DON JOHANSON: Well, I, you know, this one's broken at sort of an angle, and that'svery jagged. Yeah. I don't know. If there is anything missing between here and here, it's gotto be just a little bit.

BILL KIMBEL: It can't be very much. I'll tell you the geometry of the break on thisfragment looks perfect for fitting on the piece that—

DON JOHANSON: It looks very, very similar to the original one I found. I wonder if wecan, is this ready to lift out?

BILL KIMBEL: I think we are OK.

DON JOHANSON: Well, it's got a color match. Yep. There it is. It's perfect.

BILL KIMBEL: So how big do you think it'll be?




DON JOHANSON: You mean lengthwise?

BILL KIMBEL: Mm hm.

DON JOHANSON: I mean lengthwise, all right, if you put those together, put that outthere like that, it's going to be the length of my arm.

BILL KIMBEL: It's going to be modern-sized.

DON JOHANSON: The length of that arm bone was a real surprise, because Lucy wasonly three and a half feet tall. We urgently needed to check that all the pieces really fittogether and that meant heading back to our field lab by the side of the river. So what I'mdoing is just picking away, sand grain by sand grain, the adhering stones so that we can geta close look at what the original anatomy looked like. It's really amazing to see how muchdetail is actually preserved on these three million year old bones. Final little pieces ofsand out of the marrow chamber. Brush that off. Perfect. Just perfect. The final little pieceto the puzzle fits in right there, and fantastic. Complete ulna. Just amazing. You know, notonly is it important because it's a three million year old ulna and so beautifully complete,but because for, of what it tells us about Lucy. Comparing it to Lucy, for example, interms of anatomy, these two bones, both about three million years old, are essentiallyidentical. But it's obvious that the new ulna is nearly twice the size of Lucy's. And suchsubstantial difference in body size really has important implications for behavior. Thesefossils suggest that some of Lucy's kind were much larger than others, nearly twice the size.Such enormous differences are seen today in mountain gorillas, and it's clearly related totheir social life. This is a harem in which a single, large male controls a group of smallfemales. The silver back male is almost twice the size of the females, and this leader of thegroup, he mates with each female in turn. He can easily control all the females. In this lushenvironment, they find all the food they need without wandering far. And if any othermale tries to invade, the silver back throws in all his weight and attacks with his huge canineteeth. To survive in gorilla society, males have to be much larger than females, and havevicious fighting teeth. Finding an arm bone twice as large as Lucy's raised the possibility



(01) NOVA | Transcripts | In Search of Human Origins

that the new bone was from a large male, and that our ancestors fit the gorilla pattern, thatthey had lived in a harem. But not all the evidence fits. The landscape Lucy lived in wasvery different from the lush jungle of the gorillas. Lucy had to range widely in her searchfor food, and that would have made it hard for a single male to dominate a group offemales. And there were other clues that didn't match the gorilla model. Over the years,we've found hundreds of teeth from Lucy's kind, male and female. Surprisingly, the maleshave small canine teeth, just like the females. That could mean that there was no need formales to fight for control over females. Perhaps they weren't living in a harem after allSome scientists have speculated that the lack of fighting teeth in our ancestors means thatmales and females were paired off in monogamous couples. For now, the evidence pointsboth ways, but contradictions like this keep us questioning our ideas and looking for morefossils. What we do know is that these creatures were walking like us over three millionyears ago. And that was a distinct advantage. They could cover long distances, forage forfood, and carry it back, perhaps to a faithful mating partner. We believe Lucy's species wasthe root of the human family tree. She is our earliest ancestor, the missing link between apeand human. And what about Lucy, herself. What did she look like? We know from theteeth, the jaw and now the skull fragments we found, that Lucy had an ape-like face with abrain just a little larger than a chimps. She may have had dark skin and patchy hair toprotect her from the sun. Walking upright freed her hands to develop a more precise gripthan other apes, more like our own. And even with her small brain, perhaps she wasbeginning to have a more human like awareness of herself and her surroundings. Lucy andher kind must have been extraordinary creatures. We know that they persisted as a speciesvirtually unchanged for over a million years. That's ten times as long as we ourselves havebeen around. We know that they led relatively simple lives, because one key feature wasmissing from their behavior. Yet a few hundred thousand years after Lucy, some of herdescendants made a major breakthrough, a breakthrough that would have profoundinfluence on our own evolution. They began to make these: stone tools. Who made thesetools and why? They are a clue to the next chapter in the search for human origins.


https://news.nationalgeographic.com/news/2005/06/0624_050624_spencerwells.html

(02) 'Mitochondrial Eve': Mother of all humans lived 200,000 years ago

August 17, 2010August 17, 2010 Science News

Summary: The most robust statisticalexamination to date of our species' genetic linksto "mitochondrial Eve" -- the maternal ancestorof all living humans -- confirms that she livedabout 200,000 years ago. The study was based ona side-by-side comparison of 10 human geneticmodels that each aim to determine when Evelived using a very different set of assumptionsabout the way humans migrated, expanded andspread across Earth.

The most robust statistical examination to date ofour species' genetic links to "mitochondrial Eve" -- the maternal ancestor of all living humans --

confirms that she lived about 200,000 years ago. The Rice University study was based on aside-by-side comparison of 10 human genetic models that each aim to determine when Evelived using a very different set of assumptions about the way humans migrated, expandedand spread across Earth.

The research is available online in the journalTheoretical Population Biology.

"Our findings underscore the importance oftaking into account the random nature ofpopulation processes like growth and extinction,"said study co-author Marek Kimmel, professor ofstatistics at Rice. "Classical, deterministic models,including several that have previously beenapplied to the dating of mitochondrial Eve, do

not fully account for these random processes."




The quest to date mitochondrial Eve (mtEve) is an example of the way scientists probe thegenetic past to learn more about mutation, selection and other genetic processes that playkey roles in disease.

"This is why we are interested in patterns of genetic variability in general," Kimmel said."They are very important for medicine."

For example, the way scientists attempt to date mtEve relies on modern genetic techniques.Genetic profiles of random blood donors are compared, and based upon the likenesses anddifferences between particular genes, scientists can assign a number that describes thedegree to which any two donors are related to one another.

Using mitochondrial genomes to gauge relatedness is a way for geneticists to simplify thetask of finding common ancestors that lived long ago. That is because the entire humangenome contains more than 20,000 genes, and comparing the differences among so manygenes for distant relatives is problematic, even with today's largest and fastestsupercomputers.

But mitochondria -- the tiny organelles that serve as energy factories inside all human cells -- have their own genome. Besides containing 37 genes that rarely change, they contain a"hypervariable" region, which changes fast enough to provide a molecular clock calibratedto times comparable to the age of modern humanity. Because each person's mitochondrialgenome is inherited from his or her mother, all mitochondrial lineages are maternal.

To infer mtEve's age, scientists must convert the measures of relatedness between randomblood donors into a measure of time.

"You have to translate the differences between gene sequences into how they evolved intime," said co-author Krzysztof Cyran, vice head of the Institute of Informatics at SilesianUniversity of Technology in Gliwice, Poland. "And how they evolved in time dependsupon


https://www.huffingtonpost.com/2014/01/28/y-chromosome-adam-men-ancestor_n_4653736.html


the model of evolution that you use. So, for instance, what is the rate of genetic mutation,and is that rate of change uniform in time? And what about the process of random loss ofgenetic variants, which we call genetic drift?"

Within each model, the answers to these questions take the form of coefficients -- numericconstants that are plugged into the equation that returns the answer for when mtEve lived.

Each model has its own assumptions, and each assumption has mathematical implications.To further complicate matters, some of the assumptions are not valid for humanpopulations. For example, some models assume that population size never changes. That isnot true for humans, whose population has grown exponentially for at least severalthousand generations. Other models assume perfect mixing of genes, meaning that anytwo humans anywhere in the world have an equal chance of producing offspring.Cyran said human genetic models have become more complex over the past couple ofdecades as theorists have tried to correct for invalid assumptions. But some of thecorrections -- like adding branching processes that attempt to capture the dynamics ofpopulation growth in early human migrations -- are extremely complex. Which raises thequestion of whether less complex models might do equally well in capturing what'soccurring.

"We wanted to see how sensitive the estimates were to the assumptions of the models,"Kimmel said. "We found that all of the models that accounted for random population size-- such as different branching processes -- gave similar estimates. This is reassuring, becauseit shows that refining the assumptions of the model, beyond a certain point, may not bethat important in the big picture."

The research was supported by grants from the Polish Ministry of Science and HigherEducation and the Cancer Prevention and Research Institute of Texas. It has resulted froma standing collaboration between Rice University and Silesian University of Technology.



(03) Documentary Redraws Humans' Family Tree

Hillary Mayellfor National Geographic News

21 January, 200321 January, 2003 By analyzing DNA frompeople in all regions of the world, geneticistSpencer Wells has concluded that all humansalive today are descended from a single man wholived in Africa around 60,000 years ago.

Modern humans, he contends, didn't start theirspread across the globe until after that time. Mostarchaeologists would say the exodus began100,000 years ago—a 40,000-year discrepancy.

Wells's take on the origins of modern humansand how they came to populate the rest of theplanet is bound to be controversial.

His work adds to an already crowded field ofopposing hypotheses proposed by those who seek

answers in "stones and bones"—archaeologists and paleoanthropologists—and those whoseek them in our blood—population geneticists and molecular biologists.

Over the last decade, major debate on whether early humans evolved in Africa orelsewhere, when they began outward migration, where they went, and whether theyinterbred with or replaced archaic species has moved out of scientific journals and into thepublic consciousness.

Wells addresses these issues in a new book, The Journey of Man: A Genetic Odyssey, and aNational Geographic documentary of the same title. In a straightforward story, he explainshow he traced the exodus of modern humans from Africa by analyzing genetic changes inDNA from the y-chromosome.

https://news.nationalgeographic.com/news/2002/12/1212_021213_journeyofman.html


(03) Documentary Redraws Humans' Family Tree

"As often happens in science," he said, "technology has opened up a field to new ways ofanswering old questions—often providing startling answers."

Of course, not everyone agrees with him.



(04) Geneticist Searches for DNA of "Adam," the First Human

24 June, 200524 June, 2005 Geneticist Searches for DNA of "Adam" the First HumanGeneticist Searches for DNA of "Adam" the First HumanHillary Mayell, National Geographic News for National Geographic Channel

For many of us, the word "genetics" conjures vague thoughts of disease, the humangenome, and genetic engineering.

Spencer Wells thought "genetics" and forged a unique career that combines his love forhistory with his passion for biology. A geneticist, adventurer, author, filmmaker, andhistorian—the man adds new dimension to the term multi-tasking—he is using thecutting-edge of technology to explore human history.

He has traveled the world, collecting blood samples from people of far-flung cultures:Aborigines in Australia, the Chukchi tundra dwellers of Siberia, farmers in the hills ofAfghanistan, and nomads in the deserts of Africa. By studying the DNA of modernhumans, he seeks to learn who we are, where we traveled to populate the world, and howclosely we are all related.

"Each drop of blood is essentially a historical document," Wells said. "Our DNA tells thestory of the journey of our species."

New DNA studies suggest that all humans descended from a single African ancestor wholived some 60,000 years ago. To uncover the paths that lead from him to every livinghuman, the National Geographic Society launched the Genographic Project, headed bySpencer Wells. The quest for "Adam" is the subject of a new television documentary thatairs on the National Geographic Channel in the U.S. this Sunday.

The project is a five-year endeavor undertaken as a partnership between IBM and NationalGeographic. It will combine population genetics and molecular biology to trace themigration of humans from the time we first left Africa, 50,000 to 60,000 years ago, to theplaces where we live today.

https://news.nationalgeographic.com/news/2005/06/0624_050624_spencerwells.html

https://news.nationalgeographic.com/news/2002/12/1212_021213_journeyofman_2.html


Ten research centers around the world have received funding from the Waitt FamilyFoundation to collect and analyze blood samples from indigenous populations (such asaboriginal groups), many in remote areas. The Genographic Project hopes to collect morethan a hundred thousand DNA samples to create the largest gene bank in the world.Members of the public are also being invited to participate.

"Our DNA tells a fascinating story of the human journey: how we are all related and howour ancestors got to where we are today," Wells said. "This project will show us some of theroutes early humans followed to populate the globe and paint a picture of the genetictapestry that connects us all."

Tracing Human HistoryTracing Human History

"As often happens in science," said Wells, "technology has opened up a field to new ways ofanswering old questions—often providing startling answers."

One of the old questions that intrigued Wells was the question of human origins. Whetherearly humans evolved in Africa or elsewhere, when they began outward migration, andwhere they went, are issues that have been argued among archaeologists, anthropologists,and evolutionary biologists for decades.

By analyzing genetic changes in the Y-chromosome of people in all regions of the world,Wells and colleagues concluded that all humans alive today are descended from a singleAfrican man.

"We're all effectively cousins, separated by 2,000 generations," he said.

In his book, The Journey of Man: A Genetic Odyssey, Wells describes the exodus fromAfrica that began around 60,000 years ago, and the path we took to populate the world. Following the southern coastline of Asia, the first early travelers crossed about 250kilometers [155 miles] of sea, and colonized Australia by around 50,000 years ago. TheAborigines of Australia, Wells says, are the descendants of the first wave of migration outof Africa.

https://news.nationalgeographic.com/news/2005/06/0624_050624_spencerwells_2.html



A second wave left Africa around 45,000 years ago and settled in the Middle East, withsmaller groups going off to India, northern China, and southern China. As the glaciers ofthe Ice Age began to retreat around 40,000 years ago and temperatures warmed up,humans moved into Central Asia and multiplied quickly.

Small groups left Central Asia around 35,000 years ago for Europe. Around 20,000 yearsago, another small group of Central Asians moved farther north, into Siberia and theArctic Circle.

He and his colleagues' paper, published in the September 2003 issue of the AmericanJournal of Human Genetics, added evidence to the debate on the peopling of theAmericas. The earliest archaeological evidence of human habitation in North Americadates to 11,500 radiocarbon years old. Artifacts at a site in Monte Verde, Chile, are in the12,500-year-old range. However, there are scientists who believe there is some linguisticand archaeological evidence suggesting the possibility that people may have arrived asmuch as 30,000 years ago.

Mutations in the Y-chromosome of populations in North and South America put anupper limit on human arrival at somewhere between 18,000 to 15,000 years ago. "I wouldput the number at closer to 15,000," said Wells.

Legacy of Genghis KhanLegacy of Genghis Khan

In another study that looked at blood samples collected over a period of ten years frommore than 40 populations living in and around the former Mongol empire ofGenghis Khan, Wells and colleagues found that nearly 8 percent of the men living in theregion carry nearly identical Y-chromosomes. That translates to roughly 16 milliondescendants living today.

Archaeological finds and texts describing the history and culture of the region providesome insight into how this one lineage could be so successful, said Wells.


http://onlinelibrary.wiley.com/doi/10.1002/ajpa.1330600302/full


Khan's empire at the time of his death extended across Asia. His military conquestsfrequently entailed the wholesale slaughter of the vanquished, wiping out manypopulations. Contemporary documents report that after a conquest, looting, pillaging,and rape were the spoils of war for all soldiers, but that Khan got first pick of the beautifulwomen. In addition, his male descendants were markedly prolific. They extended theempire and maintained power in the region for several hundred years, in a culture inwhich harems and concubines were the norm. Khan's eldest son is reported to have had 40sons. His grandson, Kublai Khan, had 22 legitimate sons, and was said to add 30 virgins tohis harem each year. "This is a clear example that culture plays a very big role in patterns ofgenetic variation and diversity in human populations," said Wells.

Lost Empires Lost Empires

In addition to a general passion for history, Wells has an abiding interest in lost empires.One of his current projects involves trying to track down the Phoenicians, a civilizationthat extended from roughly 3000 B.C. to 332 B.C.

"There's remarkably little archaeological evidence of them, and yet they were thedominant culture of the time," said Wells. "Egyptian texts starting from about 1200 B.C.talk about marauding warriors arriving from the sea, yet we really have no idea who theywere or where they came from and where they went."

The Phoenicians were a seafaring people who settled a number of independent city-statesaround the Mediterranean in modern-day countries Syria, Lebanon, Israel, Tunisia,Greece, and Spain. United by a common language, their alphabet became the prototypefor the

Greek and Roman alphabets; they were the first people to circumnavigate Africa, and mayeven have reached America.

But where did they come from and where did they go? For that we'll have to wait for thenext installment of Spencer Wells' exploration.


http://onlinelibrary.wiley.com/doi/10.1002/ajpa.1330600302/full

(05) Genetic 'Adam' and 'Eve' Uncovered | LIVESCIENCE

1 August 20131 August 2013 Almost every man alive can trace his origins to one man who lived about135,000 years ago, new research suggests. And that ancient man likely shared the planetwith the mother of all women.

The findings, detailed today (Aug. 1) in the journal Science, come from the most completeanalysis of the male sex chromosome, or the Y chromosome, to date. The results overturnearlier research, which suggested that men's most recent common ancestor lived just50,000 to 60,000 years ago.

Despite their overlap in time, ancient "Adam" and ancient "Eve" probably didn't even livenear each other, let alone mate.

"Those two people didn't know each other," said Melissa Wilson Sayres, a geneticist at theUniversity of California, Berkeley, who was not involved in the study.

Tracing historyTracing history

Researchers believe that modern humans left Africa between 60,000 and 200,000 yearsago, and that the mother of all women likely emerged from East Africa. But beyond that,the details get fuzzy.

The Y chromosome is passed down identically from father to son, so mutations, or pointchanges, in the male sex chromosome can trace the male line back to the father of allhumans. By contrast, DNA from the mitochondria, the energy powerhouse of the cell, iscarried inside the egg, so only women pass it on to their children. The DNA hidden insidemitochondria, therefore, can reveal the maternal lineage to an ancient Eve.

But over time, the male chromosome gets bloated with duplicated, jumbled-up stretches ofDNA, said study co-author Carlos Bustamante, a geneticist at Stanford University inCalifornia. As a result, piecing together fragments of DNA from gene sequencing was liketrying to assemble a puzzle without the image on the box top, making thorough analysisdifficult.

https://www.livescience.com/38613-genetic-adam-and-eve-uncovered.html



Y chromosomeY chromosome

Bustamante and his colleagues assembled a much bigger piece of the puzzle by sequencingthe entire genome of the Y chromosome for 69 men from seven global populations, fromAfrican San Bushmen to the Yakut of Siberia.

By assuming a mutation rate anchored to archaeological events (such as the migration ofpeople across the Bering Strait), the team concluded that all males in their global sampleshared a single male ancestor in Africa roughly 125,000 to 156,000 years ago.

In addition, mitochondrial DNA from the men, as well as similar samples from 24women, revealed that all women on the planet trace back to a mitochondrial Eve, wholived in Africa between 99,000 and 148,000 years ago — almost the same time periodduring which the Y-chromosome Adam lived.

More ancient AdamMore ancient Adam

But the results, though fascinating, are just part of the story, said Michael Hammer, anevolutionary geneticist at the University of Arizona who was not involved in the study.

A separate study in the same issue of the journal Science found that men shared a commonancestor between 180,000 and 200,000 years ago.

And in a study detailed in March in the American Journal of Human Genetics, Hammer'sgroup showed that several men in Africa have unique, divergent Y chromosomes that traceback to an even more ancient man who lived between 237,000 and 581,000 years ago.

"It doesn't even fit on the family tree that the Bustamante lab has constructed — It's older,"Hammer told LiveScience.

Gene studies always rely on a sample of DNA and, therefore, provide an incompletepicture of human history. For instance, Hammer's group sampled a different group ofmen than Bustamante's lab did, leading to different estimates of how old commonancestors really are.


https://www.livescience.com/24718-y-chromosome-not-junk.html

http://www.sciencemag.org/news/2000/03/did-early-hominids-walk-their-knuckles


Adam and Eve?Adam and Eve?

These primeval people aren't parallel to the biblical Adam and Eve. They weren't the firstmodern humans on the planet, but instead just the two out of thousands of people alive atthe time with unbroken male or female lineages that continue on today.

The rest of the human genome contains tiny snippets of DNA from many other ancestors— they just don't show up in mitochondrial or Y-chromosome DNA, Hammer said. (Forinstance, if an ancient woman had only sons, then her mitochondrial DNA woulddisappear, even though the son would pass on a quarter of her DNA via the rest of hisgenome.)

As a follow-up, Bustamante's lab is sequencing Y chromosomes from nearly 2,000 othermen. Those data could help pinpoint precisely where in Africa these ancient humans lived.

"It's very exciting," Wilson Sayres told LiveScience. "As we get more populations across theworld, we can start to understand exactly where we came from physically."


http://www.washingtonpost.com/wp-dyn/content/article/2010/03/29/AR2010032902894.html

(06) New 'Genetic Adam' Study Links All Men | New Scientist

1/28/20141/28/2014 How old is our most common male ancestor? A new study indicates that theguy scientists call “Y-chromosomal Adam,” or “Genetic Adam,” walked the Earth around209,000 years ago.

The finding contradicts previous research indicating that the lineage of the human maledates back 338,000 years — long before the first modern humans are believed to havemade their appearance, around 200,000 years ago. The earlier finding had suggested thatthe Y (male) chromosome came into being as a result of interbreeding between Homosapiens females and the males of other hominin species. But this new study offers adifferent interpretation.

“There is no evidence to support introgression from other species,” Dr. Eran Elhaik, a co-author of the new study and a genetic epidemiologist and lecturer at the University ofSheffield in the U.K., told The Huffington Post in an email. “Modern humans’ male andfemale ancestors have emerged around the same time. Modern humans’ ancestors haveemerged or arrived to Africa a little over 200,000 years ago and gave rise to many of thepopulations in Africa who, in turn, passed their genetic information to contemporarypeople.”

To reach that conclusion, the study researchers calculated an age for the Y chromosome bymultiplying the average age fathers have their first child with the number of mutationsfound on the Y chromosome. This number was then divided by the chromosome’smutation rate, the International Business Times reported.

“We then carried the calculations using acceptable scientific methods and determined thatage to be 209,000 years old,” Dr. Elhaik said in the email. In other words, the age of‘Adam.’ But there are still many questions left unanswered.

“The question to what extent did our humans forbears interbreed with their closestrelatives is one of the hottest questions in anthropology that remains open,” Dr. Elhaik saidin a written statement. “Soon, we hope to publish a revolutionary new theory about it.”


https://www.washingtonpost.com/news/speaking-of-science/wp/2016/11/30/new-evidence-that-lucy-our-most-famous-ancestor-had-super-strong-arms/?utm_term=.fda825888ca2

What About "Lucy's" Hands/Feet?


(07) Lucy: The Beginnings of Humankind by Donald Johanson

19811981 "Make no mistake about it," says Tim. "They are likemodern human footprints. If one were left in the sand of aCalifornia beach today, and a four-year old were askedwhat it was, he would instantly say that somebody hadwalked there. He wouldn't be able to tell it from a hundredother prints on the beach, nor would you. The externalmorphology is the same. There is a well-shaped modernheel with a strong arch and good ball of the foot in thefront of it. The big toe is straight in line. It doesn't stick outto the side like an ape toe, or like the big toe in so manydrawings you see of australopithecines in books."

!"#$%&"%' ("%$)* + ,*-.' /$01)$%*' 2 345.6 7#- 8-90%%0%9& ": ;4<$%=0%*2 ' >$9- ?@A

(08) Trees have made man upright | New Scientist

New Scientist, January 20, 1983New Scientist, January 20, 1983

"Lucy's fingers are slender and curved, and her finger-bones show the marks of stronggrasping muscles and large tendons to attach the muscles. There is also evidence ofpowerful muscles to bend or flex the wrist. In these respects the hominid is very likemodern chimpanzees." Page 172

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"Johanson's student Bruce Latimer interpreted the long curved toes as evidence that"afarensis was an exceptionally strong walker, and that its elongated toes may have been ofservice to it in moving over rough stony groung, or in mud, where some slight grippingability would have been useful". For Stern and Susman, the bones tell a different story."The foot and ankle remains," they say, "reveal to us an animal that engaged in climbing aswell as bipedality. There is no evidence whatsoever that any extant primate has long,curved, heavily muscled hands and feet for any purpose other than to meet the demands offull or part-time arboreal life."" Page 176

!"#$ %&' ()*)+),)- ./0,)+1 )2 .34,-05)67,&'*34 020-'/474 8 .+'-7*0/ 9)3-/05 )2 :&147*05 ./,&-)6)5);1

(09) The Locomotor Anatomy of Australopithecus afarensis |American Journal of Physical Anthropology

March 1983March 1983 The postcranial skeleton of Australopithecus afarensisfrom the Hadar Formation, Ethiopia, and the footprints from the LaetoliBeds of northern Tanzania, are analyzed with the goal of determining (1)the extent to which this ancient hominid practiced forms of locomotionother than terrestrial bipedality, and (2) whether or not the terrestrialbipedalism of A. afarensis was notably different from that of modernhumans. It is demonstrated that A. afarensis possessed anatomic

characteristics that indicate a significant adaptation for movement in the trees. Otherstructural features point to a mode of terrestrial bipedality that involved less extension atthe hip and knee than occurs in modern humans, and only limited transfer of weight ontothe medial part of the ball of the foot, but such conclusions remain more tentative thanthat asserting substantive arboreality. A comparison of the specimens representing smallerindividuals, presumably female, to those of larger individuals, presumably male, suggestssexual differences in locomotor behavior linked to marked size dimorphism. The maleswere probably less arboreal and engaged more frequently in terrestrial bipedalism. In ouropinion, A. afarensis from Hadar is very close to what can be called a “missing link.” Wespeculate that earlier representatives of the A. afarensis lineage will present not acombination of arboreal and bipedal traits, but rather the anatomy of a generalized ape.

Carl' Notes: In this paper by Stern and Sussman state that the hands and feet ofAustralopithecus afarensis are not at all like human hands and feet; rather, they have thelong curved fingers and toes typical of arboreal primates.



Carl's Notes: On the following two charts you will see the curvature of toes and fingers ofvarious things, chimps, bonobo's, humans etc. The further to the right, the more curvedthe toes. Al333-I5G is from the Australopithecus afarensis ie. Lucy's, species. By the way,none of these bones belong to "Lucy" because they didn't find any of the hand and footbones for that individual specimen.

http://onlinelibrary.wiley.com/doi/10.1002/ajpa.1330600302/abstract



WHAT does the actual evidence show concerning the curvature of "Lucy's" hands andfeet? Were they more humanlike, transitional or apelike? Does this fit with the biblicalaccount or the naturalistic processes (evolution) account?

http://onlinelibrary.wiley.com/doi/10.1002/ajpa.1330600302/abstract


(10) Lucy Information

One of the most striking characteristics possessed by Lucy was that she had a small skull,bipedal knee structure, and molars and front teeth of human (rather than great ape) styleand relative size, but a small skull and small body. The image of a bipedal hominid withsmall skull, but teeth like a human, was somewhat shocking to the paleoanthropologicalworld at the time.

This was because during the period 1950-1970, it was believed that the development of abrain larger than an ape brain was the trigger that caused apes to evolve into humans.Before Lucy, a fossil called '1470' (Homo rudolfensis), with a brain capacity of about 800cubic centimetres had been discovered, an ape with a bigger brain, and if the 'big brain'theory was correct, then all humans should have evolved from 1470. However, it turnedout Lucy was older than 1470, yet Lucy had bipedalism (she walked upright) and had abrain that was only around 375 to 500 cc. This fact contradicts the 'big brain' theory.

BipedalismBipedalism

There are differing views on how Lucy or her ancestors first became bipedal full-time.

The so-called 'savanna theory' on how A. afarensis evolved bipedalism hangs on theevidence that around 6 - 8 million years ago there seems to have been a mass extinction offorest dwelling creatures incuding the oldest hominins recognizable: Sahelanthropustchadensis and Orrorin tugenensis. This triggered a burst of adaptive radiation, anevolutionary characteristic that generates new species quickly. Lucy's genetic forebearswere tree dwelling apes, but in Lucy's world the trees would have been much fewer, andLucy would have been forced to find a living on the flat savanna. Being bipedal wouldhave had evolutionary advantages - for example, with the eyes higher up, she could seefurther than quadrupeds. The disadvantages of bipedalism were great - Lucy was theslowest moving primate of her time, for example, but according to the hypothesis, theadvantages of bipedalism must have outweighed the disadvantages.

http://articles.latimes.com/2000/mar/23/local/me-11914


There had previously been problems in the past with designating Australopithecusafarensis as a fully bipedal hominine. In fact these hominines may have occasionally walkedupright but still walked on all fours like apes; the curved fingers on A. afarensis are similarto those of modern-day apes, which use them for climbing trees. The phalanges (fingerbones) aren't just prone to bend at the joints, but rather the bones themselves are curved.Another aspect of the Australopithecus skeleton that differs from human skeleton is theiliac crest of the pelvic bones. The iliac crest, or hip bone, on a Homo sapiens extendsfront-to-back, allowing an aligned gait. A human walks with one foot in front of the other.However, on Australopithecus and on other ape and ape-like species such as theorangutan, the iliac crest extends laterally (out to the side), causing the legs to stick out tothe side, not straight forward. This gives a side-to-side rocking motion as the animal walks,not a forward gait.

The so-called aquatic ape theory compares the typical elements of human locomotion(truncal erectness, aligned body, two-leggedness, striding gait, very long legs, valgus knees,plantigrady etc.) with those of chimpanzees and other animals, and proposes that humanancestors evolved from vertical wader-climbers who operated in coastal or swamp forests toshoreline dwellers who collected coconuts, turtles, bird eggs, shellfish etc. by beach-combing, wading and diving. In this view, the australopithecines largely conserved theancestral vertical wading-climbing locomotion in swamp forests ("gracile" kind, includingAustralopithecus afarensis and A. africanus) and later more open wetlands ("robust" kind,including Paranthropus boisei and P. robustus). Meanwhile, Plio-Pleistocene Homo haddispersed along the African Rift valley lakes and African and Indian ocean coasts, fromwhere different Homo populations ventured inland along rivers and lakes.

Social characteristicsSocial characteristics

These hominines were likely to be somewhat like modern Homo sapiens when it came tothe matter of social behaviour, yet like modern day apes they relied on the safety of treesfrom predators such as lions.



Fossil sites and findingsFossil sites and findings

Australopithecus afarensis fossils have only been discovered within Eastern Africa, whichinclude Ethiopia (Hadar, Aramis), Tanzania (Laetoli) and Kenya (Omo, Turkana, KoobiFora and Lothagam).

A major discovery made by Don Johnson after Lucy's find he discovered the "First Family"including 200 hominid fragments of A. afarensis, discovered near Lucy on the other sideof the hillin the Afar region. The site is known as "site 333", by a count of fossil fragmentsuncovered, such as teeth and pieces of jaw. 13 individuals were uncovered and all wereadults, with no injuries caused by carnivores. All 13 individuals seemed to have died at thesame time, thus Don concluded that they might have been killed instantly from a flashflood.

Related workRelated work

Further findings at Afar, including the many hominin bones in "site 333", produced morebones of concurrent date, and led to Johanson and White's eventual argument that theKoobi Fora hominins were concurrent with the Afar hominins. In other words, Lucy wasnot unique in evolving bipedalism and a flat face.

ReferencesReferences

* BBC - Dawn of Man (2000) by Robin Mckie| ISBN 0-7894-6262-1

* Australopithecus afarensis from The Human Origins Program at the SmithsonianInstitution

External links

* Lucy at the Institute of Human Origins at Arizona State University

* http://www.geocities.com/palaeoanthropology/Aafarensis.html

http://planet.botany.uwc.ac.za/nisl/Scientific_methods/attachments/Chapter1_notes.html


(11) Extinct Humans by Ian Tattersall

12/05/2001 12/05/2001 Peter Schmid's reconstruction of "Lucy's"skeleton is quite different from that of OwenLovejoy, who had worked with Johanson on thefossil. For instance, in the Schmid reconstructionthe bladelike portions of the pelvis are orientedmuch more horizontally, giving a wider andshallower appearance to the structure as a whole.Since major back muscles attach from thebladelike parts of the pelvis to the lower ribs, itmakes sense that the lower end of the rib cagewould also have been quite wide--which means,in turn, that the rib cage would have taperedupward quite strongly.

In keeping with Lucy have had long and strongly curved finger and toe bones, as dochimpanzees and orangutans, Schmid's reconstruction also emphasizes the long armstypical of an arboreal hominoid.Photograph courtesy of Peter Schmid.

Tattersall, Ian & Schwartz, Jeffrey, "Extinct Humans", page 90


(12) Vertebrate Palaeontology by Michael J. Benton

20052005 Basal hominins flourished in the Pliocene.In a change from previous terminology, most ofthese humans have now been referred toPraeanthropus, a little-known genus establishedin 1948 for a jaw fragment from the Pliocene ofKenya. The various species have been shown toform a monophyletic group by Strait et al.(1997), Wood and Collard (1999) and Cameron(2003) that is distinct from Australopithecusproper (see below). Cela-Conde and Ayala(2003) also include Orrorin withinPraeanthropus. These technical disputes have tobe sorted out!

Leakey et al. (1995) reported an ancienthominin, Praeanthropus anamensis, from

sediments 4.1 to 3.9Myr old near Lake Turkana in Kenya, that appears to be anintermediate beween Ardipithecus and later species. The remains include jaws, a humerus,a tibia and isolated teeth. It has a primitive jaw with a shallow palate and large canines. Thetibia shows, however, that P. anamensis was a biped.

The most complete skeleton of a Mio-Pliocene hominin, Praeanthropus afarensis, wasdiscovered by Donald Johanson and colleagues in Ethiopia in 1974. The skeleton was froma young female, nicknamed Lucy, which consisted of 40% of the bones, unusuallycomplete by usual standards (Figure 11.9(b)). Some 240 specimens were found at Hadar inthe 1970s and 50 new specimens have been found in the 1990s, including a good skull(Kimbel et al., 1994). Lucy is dated as 3.2 Myr old and P. afarensis specimens range from3.2 to 2.9 Myr in age. Further specimens from Laetoli in Tanzania are dated as 3.6-3.7Myr old. These include some bones and the famous trackway of bipedal footprints.

Benton, Michael J., "Vertebrate Palaeontology", pages 279-280


(12) Vertebrate Palaeontology by Michael J. Benton

Praeanthropus afarensis individuals are 1-1.2 m tall, with a brain size of only 415 cm3 anda generally ape-like face. Other primitive characters include the presence of a smalldiastema (Figure 11.9(c)), long arms and rather short legs and curved finger and toe bones(Figure 11.9(d-f)). These curved bones imply that Lucy still used her hands and feet ingrasping branches, as apes do. In addition, there are specializations in the wrist, whichsuggest that P. afarensis (and P. anamensis) had evolved from a not-too-distant knuckle-walking ancestor (Richmond and Strait, 2000), a specialized mode of locomotion retainedtoday by chimps and gorillas.

Benton, Michael J., "Vertebrate Palaeontology", pages 279-280


(13) Little 'Lucy' Fossil Found | Nature

Toddler hominin has arms for swinging and legs for walking.Toddler hominin has arms for swinging and legs for walking.

Little Salem is the most ancient toddler ever found.

Zeresenay Alemseged and Copyright Authority for Research and Conservation of Cultrual Heritages (ARCCH)

9/20/20069/20/2006In today's issue of Nature, an Ethiopian-led international team reports the discovery of ajuvenile skeleton of the species commonly known as 'Lucy', or Australopithecusafarensis.1,2 The researchers have named her Selam, after an Ethiopian word for 'peace'.

The specimen, which is the oldest and most complete juvenile of a human relative everfound, has features that stand as striking examples of part-way evolution between primitiveapes and modern humans.

Although many other samples of A. afarensis have been found before, this is the first onereported to come complete with a whole shoulder-blade bone (scapula). In modernhumans the scapula has a ridge running horizontally across the top of the bone; in apes thescapula's ridge reaches further down the back, where it can help to throw more muscle intoarm action, as would be needed to swing from trees. In the young A. afarensis, the scapulalooks to be part-way between.

"The animal was losing its capacity to be arboreal — heading right toward being human,"says anthropologist Owen Lovejoy of Kent State University in Ohio.

http://www.nature.com/news/2006/060918/full/news060918-5.html



The ridge on little Lucy's shoulder blade (a) is intermediate between that of gorillas and chimps (b and d) and modern humans

Other hominins have been found before with traits that similarly show a cross between alife in the trees and one on the ground. A. afarensis, for example, has previously beenfound to have hips and knees thought to be adapted to standing upright, but curved fingerssuited to grabbing branches.

But 'little Lucy' is a particularly striking example of this sort of mosaic of evolution, saysZeresenay Alemseged, lead researcher on the paper and a paleoanthropologist at the MaxPlanck Institute for Evolutionary Anthropology at Leipzig, Germany.

"These hominid fossils clearly show evolution in the making," he says.

Little starThe fossils were unearthed at Dikika, just a few kilometres from the Hadar site in the Afarregion of eastern Ethiopia — which in 1974 produced the original skeleton of Lucy,named after the Beetles song 'Lucy in the Sky with Diamonds', which was played duringcelebrations of the find's discovery.

When the first Dikika fossils were uncovered in 2000, Alemseged says it was unclearexactly what it was. But after comparison with specimens at the National Museum inAddis Ababa, he realized it was a young A. Afarensis.

http://articles.latimes.com/2000/mar/23/local/me-11914


Young bones are more fragile than their adult versions and seldom survive the rigors oftime. This set survived in compressed sandstone sediments that probably washed over theyoung girl in a flood. It has taken five years to laboriously clean away from the bone usingdental tools.

The specimen includes a skull (large enough for a chimp-sized brain), a near-complete setof teeth, and all of the major limb components.

Having such a complete set will provide researchers with a way to study developmentalgrowth in this species.

References

1. Alemseged Z., et al. Nature, 443. 296 - 301 (2006). 2. Wynn J. G., et al. Nature, 443. 332 - 336 (2006).


(14) Masters of the Planet by Ian Tattersall

3/27/20123/27/2012

"While numerous features of the pelvis attestbeyond doubt that Lucy was a biped, othersreveal that she was not bipedal in quite the sameway we are."

"What's more, while Lucy herself possesses only acouple of preserved foot bones, parts of the footattributed to other individuals of her speciesindicate that her feet would have been quite long,and her toes a bit curved (although the mid-footmay have been relatively advanced). This wascertainly not a committed branch-grasping footlike the ones we see in the modern apes andArdipithecus, with their long, curved digits andwidely divergent big toes; but it is a foot thatwould have been substantially more capable in

the trees than ours are. The bones of Lucy's upper limb continue the arboreal theme,although relative to the rest of her body her arms were shorter than those of bonobos. Herrib cage, however, tapered sharply upward from its broad base, so that the somewhatupwardly oriented shoulder joints were quite closely spaced. Bot of these attributes wouldhave been pretty useful in the trees. And while the Lucy skeleton is a bit short on hand bones as well as those of the foot, handelements from other Asutralopithecus afarensis individuals found at Hadar are muchshorter than those of apes, but still show some ape-like features of the wrist bones incombination with finger bones that are quite curved. They also show markings for strongflexor tendons, signifying a strong grasping ability. Taking everything into account, apicture emerges of Australopithedus afarensis as a creature less fully adapted to bipedalitythan we are, but much more capable than us in trees.

Tattersall, Ian, "Masters of the Planet", pages 30-31


(15) Did Early Hominids Walk on Their Knuckles? | Science

11/30/201611/30/2016 In Ethiopia, sheis known as “Dinkinesh” —Amharic for “you aremarvelous.” It's an apt name forone of the most completeancient hominid skeletons everfound, an assemblage offossilized bones that has givenscientists unprecedented insightinto the history of humanity.

Discovered in 1974, wedged into a gully in Ethiopia's Awash Valley, the delicate,diminutive skeleton is both uncannily familiar and alluringly strange. In some ways, the3.2-million-year-old Australopithecus was a lot like us; her hips, feet and long legs wereclearly made for walking. But she also had long arms and dexterous curved fingers, muchlike modern apes that still swing from the trees.

You probably know her as Lucy.

So, for decades scientists have wondered: Who exactly was Lucy? Was she lumbering andland-bound, like us modern humans? Or did she retain some of the ancient climbingabilities that made her ancestors — and our own — champions of the treetops?

A new study suggests she was a little of both: Though her lower limbs were adapted forbipedalism, she had exceptionally strong arm bones that allowed her to haul herself upbranches, researchers reported Wednesday in the journal PLoS One.

“This is what makes Lucy so fascinating,” said lead author Christopher Ruff, a biologicalanthropologist at Johns Hopkins School of Medicine. “She had crossed a lot ofthresholds on the path to becoming human, but not all of them.”

https://www.washingtonpost.com/news/speaking-of-science/wp/2016/11/30/new-evidence-that-lucy-our-most-famous-ancestor-had-super-strong-arms/?utm_term=.eb7bffe22ebf


The research is the latest installment in a decades-old debate on how much time Lucy spentin trees. Just a few months ago, a team of researchers led by John Kappelman and RichardKetcham — two co-authors on the new study — published a paper arguing that Lucy diedafter falling from a tree. (That conclusion proved fairly contentious, even bypaleoanthropology's standards.)

It's no easy task to reconstruct the lifestyle of a hominid who's been dead for 3.2 millionyears. Fossils are bone turned to rock, making them impenetrable to the kinds of CT scansthat were available for the first several decades after Lucy was discovered. Scientists candraw conclusions about Lucy's habits based on the shape of her skeleton — noting, forexample, that her legs bent at the knee (an adaptation for bipedal walking) and her arms aremuch longer than those of a modern human (which would make her well suited for life inthe trees).

But Ruff noted that those more chimp-like traits could be evidence of primitive retention— ancestral traits that stay in the skeleton even though they're no longer used.

“If she evolved from a more arboreal ancestor she may just not have had the time yet toevolve a shorter upper limb,” he said. “We have to look at traits that changed during her lifedepending on how she used that part of her skeleton — that’s real evidence of whatsomeone was actually doing.”

Luckily, bones develop “strength characteristics” in response to heavy use; you can tellwhat arm a professional tennis player served with just by looking at a scan of her skeleton.And scientists at the University of Texas had advanced micro CT scanners capable offinding these characteristics in fossilized bone. So, during a 2008 tour of the U.S., Lucymade a pit stop at the UT lab in Austin to be scanned.


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The UT researchers produced cross sections of Lucy's right and left humeri (upper armbones) and her left femur (thigh bone). They then compared the relative strength of thosebones to samples from a range of other primate species. Lucy's arms were not as strong asthose of chimps, but they were substantially stronger than those of us puny modernhumans.

“And we know she wasn't playing tennis,” Ruff quipped.

He argues that daily tree climbing is the most likely explanation for the strength of Lucy'sarms: “You don’t develop strong limb bones like that unless you do it a lot,” Ruff said.Perhaps Lucy and her relatives ventured into trees at night to prevent attacks frompredators as they slept.

“Hominins had slowly developed adaptations for walking on the ground, but for millionsof years we were still using the trees in a significant way,” he added. “Really, it was onlywith evolution of Homo the genus” — about half a million years after Lucy — “that webecame fully committed to the ground.”

Carol Ward, a paleoanthropologist and professor of anatomy at the University of Missouri,said the scans of Lucy's skeleton were well done and agreed that her arms were clearlystrong. But she's more skeptical of Ruff's conclusions about the importance of her treeclimbing.

"The important part of science is asking the right questions of our data,” she said. " . . . The kind of question that will really tell you about the forces that shaped our evolution is, whatwas natural selection asking hominins to do? What were the behaviors that were soimportant that animals that didn't do them well left fewer surviving babies andgrandbabies?”

“The answer to that question for Lucy is very clearly moving well on the ground,” sheconcluded.


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Ward noted that Lucy, like modern humans, lacks an opposable big toe that lets otherapes grasp tree branches with their feet — an important tool for true climbers. And theremay be alternative explanations for Lucy's upper body strength that scientists haven'tconsidered yet.

The debate over Lucy's tree-climbing habits may seem esoteric, but it's an importantone. Our ancestors' adoption of bipedalism is one of the most important developments inthe history of humanity; it freed up our hands for hunting and gathering, made us long-distance travelers, and saved energy for other activities. If evolutionary biologists want tounderstand why this transition happened, they need to understand when it happened —and Lucy's stunningly complete skeleton is ideal for a case study.

The micro CT scans conducted in Austin offered other insights into Lucy's life history.Mechanical analyses suggest that her gait was much less efficient than that of modernhumans — she wouldn't have been able to do the kind of long distance traveling thatwould lead her immediate successors out of Africa.

Additionally, her bones suggest she had a relatively small brain for her body size andrelatively large muscles. That seems to support other research arguing that there is anevolutionary trade-off between brawn and brains; human noggins could only get bigger ifwe stopped expending so much energy on big muscles.

“It's kind of a nice evolutionary story there,” Ruff said.

Lucy is full of these stories. At 3.2 million years old, her species represents the roughhalfway point in human evolution (we split from our last common ancestor withchimpanzees about 6 million years ago). With her arms in the past and her feet in thefuture, she is a creature on the cusp of becoming human. In a matter of a few hundredthousand years, Homo habilis would emerge — the first member of the genus that wouldsomeday include all of us.


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“There's no topic that fascinates us more than ourselves,” Ward said. “Where did we comefrom? How did we get here. Why are we the way we are?”

More than 40 years after her discovery, Lucy is still helping to answer those questions.


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(01) NOVA | Transcripts | In Search of Human...(01) NOVA | Transcripts | In Search of Human Origins taken it up themselves to guard us personally, because this is also bandit country