The Great Human Migration

Why humans left their African homeland 80,000 years ago to colonize the world

By Guy Gugliotta
Smithsonian magazine, July 2008, Subscribe

Christopher Henshilwood (in Blombos Cave) dug at one of the most important early human sites partly out of proximity—it’s on his grandfather’s property. (Centre for Development Studies, University of Bergen, Norway)

(Page 2 of 5)

When the study of human origins intensified in the 20th century, two main theories emerged to explain the archaeological and fossil record: one, known as the multi-regional hypothesis, suggested that a species of human ancestor dispersed throughout the globe, and modern humans evolved from this predecessor in several different locations. The other, out-of-Africa theory, held that modern humans evolved in Africa for many thousands of years before they spread throughout the rest of the world.

In the 1980s, new tools completely changed the kinds of questions that scientists could answer about the past. By analyzing DNA in living human populations, geneticists could trace lineages backward in time. These analyses have provided key support for the out-of-Africa theory. Homo sapiens, this new evidence has repeatedly shown, evolved in Africa, probably around 200,000 years ago.

The first DNA studies of human evolution didn't use the DNA in a cell's nucleus—chromosomes inherited from both father and mother—but a shorter strand of DNA contained in the mitochondria, which are energy-producing structures inside most cells. Mitochondrial DNA is inherited only from the mother. Conveniently for scientists, mitochondrial DNA has a relatively high mutation rate, and mutations are carried along in subsequent generations. By comparing mutations in mitochondrial DNA among today's populations, and making assumptions about how frequently they occurred, scientists can walk the genetic code backward through generations, combining lineages in ever larger, earlier branches until they reach the evolutionary trunk.

At that point in human history, which scientists have calculated to be about 200,000 years ago, a woman existed whose mitochondrial DNA was the source of the mitochondrial DNA in every person alive today. That is, all of us are her descendants. Scientists call her "Eve." This is something of a misnomer, for Eve was neither the first modern human nor the only woman alive 200,000 years ago. But she did live at a time when the modern human population was small—about 10,000 people, according to one estimate. She is the only woman from that time to have an unbroken lineage of daughters, though she is neither our only ancestor nor our oldest ancestor. She is, instead, simply our "most recent common ancestor," at least when it comes to mitochondria. And Eve, mitochondrial DNA backtracking showed, lived in Africa.

Subsequent, more sophisticated analyses using DNA from the nucleus of cells have confirmed these findings, most recently in a study this year comparing nuclear DNA from 938 people from 51 parts of the world. This research, the most comprehensive to date, traced our common ancestor to Africa and clarified the ancestries of several populations in Europe and the Middle East.

While DNA studies have revolutionized the field of paleoanthropology, the story "is not as straightforward as people think," says University of Pennsylvania geneticist Sarah A. Tishkoff. If the rates of mutation, which are largely inferred, are not accurate, the migration timetable could be off by thousands of years.

To piece together humankind's great migration, scientists blend DNA analysis with archaeological and fossil evidence to try to create a coherent whole—no easy task. A disproportionate number of artifacts and fossils are from Europe—where researchers have been finding sites for well over 100 years—but there are huge gaps elsewhere. "Outside the Near East there is almost nothing from Asia, maybe ten dots you could put on a map," says Texas A&M University anthropologist Ted Goebel.

As the gaps are filled, the story is likely to change, but in broad outline, today's scientists believe that from their beginnings in Africa, the modern humans went first to Asia between 80,000 and 60,000 years ago. By 45,000 years ago, or possibly earlier, they had settled Indonesia, Papua New Guinea and Australia. The moderns entered Europe around 40,000 years ago, probably via two routes: from Turkey along the Danube corridor into eastern Europe, and along the Mediterranean coast. By 35,000 years ago, they were firmly established in most of the Old World. The Neanderthals, forced into mountain strongholds in Croatia, the Iberian Peninsula, the Crimea and elsewhere, would become extinct 25,000 years ago. Finally, around 15,000 years ago, humans crossed from Asia to North America and from there to South America.

Seventy-seven thousand years ago, a craftsman sat in a cave in a limestone cliff overlooking the rocky coast of what is now the Indian Ocean. It was a beautiful spot, a workshop with a glorious natural picture window, cooled by a sea breeze in summer, warmed by a small fire in winter. The sandy cliff top above was covered with a white-flowering shrub that one distant day would be known as blombos and give this place the name Blombos Cave.

The man picked up a piece of reddish brown stone about three inches long that he—or she, no one knows—had polished. With a stone point, he etched a geometric design in the flat surface—simple crosshatchings framed by two parallel lines with a third line down the middle.

Today the stone offers no clue to its original purpose. It could have been a religious object, an ornament or just an ancient doodle. But to see it is to immediately recognize it as something only a person could have made. Carving the stone was a very human thing to do.

The scratchings on this piece of red ocher mudstone are the oldest known example of an intricate design made by a human being. The ability to create and communicate using such symbols, says Christopher Henshilwood, leader of the team that discovered the stone, is "an unambiguous marker" of modern humans, one of the characteristics that separate us from any other species, living or extinct.

Henshilwood, an archaeologist at Norway's University of Bergen and the University of the Witwatersrand, in South Africa, found the carving on land owned by his grandfather, near the southern tip of the African continent. Over the years, he had identified and excavated nine sites on the property, none more than 6,500 years old, and was not at first interested in this cliffside cave a few miles from the South African town of Still Bay. What he would find there, however, would change the way scientists think about the evolution of modern humans and the factors that triggered perhaps the most important event in human prehistory, when Homo sapiens left their African homeland to colonize the world.

This great migration brought our species to a position of world dominance that it has never relinquished and signaled the extinction of whatever competitors remained—Neanderthals in Europe and Asia, some scattered pockets of Homo erectus in the Far East and, if scholars ultimately decide they are in fact a separate species, some diminutive people from the Indonesian island of Flores (see "Were 'Hobbits' Human?"). When the migration was complete, Homo sapiens was the last—and only—man standing.

Even today researchers argue about what separates modern humans from other, extinct hominids. Generally speaking, moderns tend to be a slimmer, taller breed: "gracile," in scientific parlance, rather than "robust," like the heavy-boned Neanderthals, their contemporaries for perhaps 15,000 years in ice age Eurasia. The modern and Neanderthal brains were about the same size, but their skulls were shaped differently: the newcomers' skulls were flatter in back than the Neanderthals', and they had prominent jaws and a straight forehead without heavy brow ridges. Lighter bodies may have meant that modern humans needed less food, giving them a competitive advantage during hard times.

The moderns' behaviors were also different. Neanderthals made tools, but they worked with chunky flakes struck from large stones. Modern humans' stone tools and weapons usually featured elongated, standardized, finely crafted blades. Both species hunted and killed the same large mammals, including deer, horses, bison and wild cattle. But moderns' sophisticated weaponry, such as throwing spears with a variety of carefully wrought stone, bone and antler tips, made them more successful. And the tools may have kept them relatively safe; fossil evidence shows Neanderthals suffered grievous injuries, such as gorings and bone breaks, probably from hunting at close quarters with short, stone-tipped pikes and stabbing spears. Both species had rituals—Neanderthals buried their dead—and both made ornaments and jewelry. But the moderns produced their artifacts with a frequency and expertise that Neanderthals never matched. And Neanderthals, as far as we know, had nothing like the etching at Blombos Cave, let alone the bone carvings, ivory flutes and, ultimately, the mesmerizing cave paintings and rock art that modern humans left as snapshots of their world.

Africa is relatively rich in the fossils of human ancestors who lived millions of years ago (see timeline, opposite). Lush, tropical lake country at the dawn of human evolution provided one congenial living habitat for such hominids as Australopithecus afarensis. Many such places are dry today, which makes for a congenial exploration habitat for paleontologists. Wind erosion exposes old bones that were covered in muck millions of years ago. Remains of early Homo sapiens, by contrast, are rare, not only in Africa, but also in Europe. One suspicion is that the early moderns on both continents did not—in contrast to Neanderthals—bury their dead, but either cremated them or left them to decompose in the open.

In 2003, a team of anthropologists reported the discovery of three unusual skulls—two adults and a child—at Herto, near the site of an ancient freshwater lake in northeast Ethiopia. The skulls were between 154,000 and 160,000 years old and had modern characteristics, but with some archaic features. "Even now I'm a little hesitant to call them anatomically modern," says team leader Tim White, from the University of California at Berkeley. "These are big, robust people, who haven't quite evolved into modern humans. Yet they are so close you wouldn't want to give them a different species name."

The Herto skulls fit with the DNA analysis suggesting that modern humans evolved some 200,000 years ago. But they also raised questions. There were no other skeletal remains at the site (although there was evidence of butchered hippopotamuses), and all three skulls, which were nearly complete except for jawbones, showed cut marks—signs of scraping with stone tools. It appeared that the skulls had been deliberately detached from their skeletons and defleshed. In fact, part of the child's skull was highly polished. "It is hard to argue that this is not some kind of mortuary ritual," White says.

Even more provocative were discoveries reported last year. In a cave at Pinnacle Point in South Africa, a team led by Arizona State University paleoanthropologist Curtis Marean found evidence that humans 164,000 years ago were eating shellfish, making complex tools and using red ocher pigment—all modern human behaviors. The shellfish remains—of mussels, periwinkles, barnacles and other mollusks—indicated that humans were exploiting the sea as a food source at least 40,000 years earlier than previously thought.

The first archaeological evidence of a human migration out of Africa was found in the caves of Qafzeh and Skhul, in present-day Israel. These sites, initially discovered in the 1930s, contained the remains of at least 11 modern humans. Most appeared to have been ritually buried. Artifacts at the site, however, were simple: hand axes and other Neanderthal-style tools.

At first, the skeletons were thought to be 50,000 years old—modern humans who had settled in the Levant on their way to Europe. But in 1989, new dating techniques showed them to be 90,000 to 100,000 years old, the oldest modern human remains ever found outside Africa. But this excursion appears to be a dead end: there is no evidence that these moderns survived for long, much less went on to colonize any other parts of the globe. They are therefore not considered to be a part of the migration that followed 10,000 or 20,000 years later.

Intriguingly, 70,000-year-old Neanderthal remains have been found in the same region. The moderns, it would appear, arrived first, only to move on, die off because of disease or natural catastrophe or—possibly—get wiped out. If they shared territory with Neanderthals, the more "robust" species may have outcompeted them here. "You may be anatomically modern and display modern behaviors," says paleoanthropologist Nicholas J. Conard of Germany's University of Tübingen, "but apparently it wasn't enough. At that point the two species are on pretty equal footing." It was also at this point in history, scientists concluded, that the Africans ceded Asia to the Neanderthals.

Then, about 80,000 years ago, says Blombos archaeologist Henshilwood, modern humans entered a "dynamic period" of innovation. The evidence comes from such South African cave sites as Blombos, Klasies River, Diepkloof and Sibudu. In addition to the ocher carving, the Blombos Cave yielded perforated ornamental shell beads—among the world's first known jewelry. Pieces of inscribed ostrich eggshell turned up at Diepkloof. Hafted points at Sibudu and elsewhere hint that the moderns of southern Africa used throwing spears and arrows. Fine-grained stone needed for careful workmanship had been transported from up to 18 miles away, which suggests they had some sort of trade. Bones at several South African sites showed that humans were killing eland, springbok and even seals. At Klasies River, traces of burned vegetation suggest that the ancient hunter-gatherers may have figured out that by clearing land, they could encourage quicker growth of edible roots and tubers. The sophisticated bone tool and stoneworking technologies at these sites were all from roughly the same time period—between 75,000 and 55,000 years ago.

Virtually all of these sites had piles of seashells. Together with the much older evidence from the cave at Pinnacle Point, the shells suggest that seafood may have served as a nutritional trigger at a crucial point in human history, providing the fatty acids that modern humans needed to fuel their outsize brains: "This is the evolutionary driving force," says University of Cape Town archaeologist John Parkington. "It is sucking people into being more cognitively aware, faster-wired, faster-brained, smarter." Stanford University paleoanthropologist Richard Klein has long argued that a genetic mutation at roughly this point in human history provoked a sudden increase in brainpower, perhaps linked to the onset of speech.

Did new technology, improved nutrition or some genetic mutation allow modern humans to explore the world? Possibly, but other scholars point to more mundane factors that may have contributed to the exodus from Africa. A recent DNA study suggests that massive droughts before the great migration split Africa's modern human population into small, isolated groups and may have even threatened their extinction. Only after the weather improved were the survivors able to reunite, multiply and, in the end, emigrate. Improvements in technology may have helped some of them set out for new territory. Or cold snaps may have lowered sea level and opened new land bridges.

Whatever the reason, the ancient Africans reached a watershed. They were ready to leave, and they did.

DNA evidence suggests the original exodus involved anywhere from 1,000 to 50,000 people. Scientists do not agree on the time of the departure—sometime more recently than 80,000 years ago—or the departure point, but most now appear to be leaning away from the Sinai, once the favored location, and toward a land bridge crossing what today is the Bab el Mandeb Strait separating Djibouti from the Arabian Peninsula at the southern end of the Red Sea. From there, the thinking goes, migrants could have followed a southern route eastward along the coast of the Indian Ocean. "It could have been almost accidental," Henshilwood says, a path of least resistance that did not require adaptations to different climates, topographies or diet. The migrants' path never veered far from the sea, departed from warm weather or failed to provide familiar food, such as shellfish and tropical fruit.

Tools found at Jwalapuram, a 74,000-year-old site in southern India, match those used in Africa from the same period. Anthropologist Michael Petraglia of the University of Cambridge, who led the dig, says that although no human fossils have been found to confirm the presence of modern humans at Jwalapuram, the tools suggest it is the earliest known settlement of modern humans outside of Africa except for the dead enders at Israel's Qafzeh and Skhul sites.

And that's about all the physical evidence there is for tracking the migrants' early progress across Asia. To the south, the fossil and archaeological record is clearer and shows that modern humans reached Australia and Papua New Guinea—then part of the same landmass—at least 45,000 years ago, and maybe much earlier.

But curiously, the early down under colonists apparently did not make sophisticated tools, relying instead on simple Neanderthal-style flaked stones and scrapers. They had few ornaments and little long-distance trade, and left scant evidence that they hunted large marsupial mammals in their new homeland. Of course, they may have used sophisticated wood or bamboo tools that have decayed. But University of Utah anthropologist James F. O'Connell offers another explanation: the early settlers did not bother with sophisticated technologies because they did not need them. That these people were "modern" and innovative is clear: getting to New Guinea-Australia from the mainland required at least one sea voyage of more than 45 miles, an astounding achievement. But once in place, the colonists faced few pressures to innovate or adapt new technologies. In particular, O'Connell notes, there were few people, no shortage of food and no need to compete with an indigenous population like Europe's Neanderthals.

Modern humans eventually made their first forays into Europe only about 40,000 years ago, presumably delayed by relatively cold and inhospitable weather and a less than welcoming Neanderthal population. The conquest of the continent—if that is what it was—is thought to have lasted about 15,000 years, as the last pockets of Neanderthals dwindled to extinction. The European penetration is widely regarded as the decisive event of the great migration, eliminating as it did our last rivals and enabling the moderns to survive there uncontested.

Did modern humans wipe out the competition, absorb them through interbreeding, outthink them or simply stand by while climate, dwindling resources, an epidemic or some other natural phenomenon did the job? Perhaps all of the above. Archaeologists have found little direct evidence of confrontation between the two peoples. Skeletal evidence of possible interbreeding is sparse, contentious and inconclusive. And while interbreeding may well have taken place, recent DNA studies have failed to show any consistent genetic relationship between modern humans and Neanderthals.

"You are always looking for a neat answer, but my feeling is that you should use your imagination," says Harvard University archaeologist Ofer Bar-Yosef. "There may have been positive interaction with the diffusion of technology from one group to the other. Or the modern humans could have killed off the Neanderthals. Or the Neanderthals could have just died out. Instead of subscribing to one hypothesis or two, I see a composite."

Modern humans' next conquest was the New World, which they reached by the Bering Land Bridge—or possibly by boat—at least 15,000 years ago. Some of the oldest unambiguous evidence of humans in the New World is human DNA extracted from coprolites—fossilized feces—found in Oregon and recently carbon dated to 14,300 years ago.

For many years paleontologists still had one gap in their story of how humans conquered the world. They had no human fossils from sub-Saharan Africa from between 15,000 and 70,000 years ago. Because the epoch of the great migration was a blank slate, they could not say for sure that the modern humans who invaded Europe were functionally identical to those who stayed behind in Africa. But one day in 1999, anthropologist Alan Morris of South Africa's University of Cape Town showed Frederick Grine, a visiting colleague from Stony Brook University, an unusual-looking skull on his bookcase. Morris told Grine that the skull had been discovered in the 1950s at Hofmeyr, in South Africa. No other bones had been found near it, and its original resting place had been befouled by river sediment. Any archaeological evidence from the site had been destroyed—the skull was a seemingly useless artifact.

But Grine noticed that the braincase was filled with a carbonate sand matrix. Using a technique unavailable in the 1950s, Grine, Morris and an Oxford University-led team of analysts measured radioactive particles in the matrix. The skull, they learned, was 36,000 years old. Comparing it with skulls from Neanderthals, early modern Europeans and contemporary humans, they discovered it had nothing in common with Neanderthal skulls and only peripheral similarities with any of today's populations. But it matched the early Europeans elegantly. The evidence was clear. Thirty-six thousand years ago, says Morris, before the world's human population differentiated into the mishmash of races and ethnicities that exist today, "We were all Africans."

Guy Gugliotta has written about cheetahs, Fidel Castro and London's Old Bailey courthouse for Smithsonian.

Single Page « Previous 1 2 3 4 5 Next »

Subscribe now for more of Smithsonian's coverage on history, science and nature.

Comments (36)

I do not understand why modern man or neanderthal would migrate to areas of a cold climate. I cannot believe early man would have the ability to adapt and thrive in this type of climate. Obvisiously they did, however, something is not quite right with this scenario.

Posted by Joe on January 14,2013 | 10:32 PM

It is very rich. But if u give the headline of every paragraph then it can be more easy to see at a glance. Thank you.

Posted by Mojahar plabon on October 12,2012 | 12:30 AM

nice!

Posted by nicolas on October 6,2012 | 07:23 PM

i wanted to find out why migration was common now than 200 years ago!

Posted by on September 29,2012 | 06:22 AM

to much writing i got bored

Posted by toni-leighnicholls on June 1,2012 | 08:46 AM

On Culture, Genetics And Stubbornness...

On Bigger Human Brain, Horse And Wagon

A.
Change during human evolution could have led to bigger brains. http://www.sciencenews.org/view/generic/id/335200/title/Doubled_gene_means_extra_smarts

B.
On Culture And Genetics, Horses And Wagon
http://universe-life.com/2011/08/26/on-culture-and-genetics-horses-and-wagon/
If you saw it once, you saw it a million times: it’s the horses pulling, not the wagon pushing !

C.
Enough with the AAAS trade-union mandated science peer-review ignorance. It’s culture that modifies genetics, not genetics that modifies culture.

Dov Henis (comments from 22nd century)

Posted by Dov Henis on October 16,2011 | 10:57 AM

This was an interesting thing to read. It gave me a lot of information... but not close too what I wanted.

~Cora

Posted by Cora on October 2,2011 | 11:07 AM

Is this not all but a lot of theory,speculation and conjecture? Man has always been fully man,created as such so why try turn certain fossil finds into "evidence" of man being half ape(ie hominids,hobbits,neanderthels etc) at any stage of his existence? Both the geological and archaelogical record support sudden life forms(human and animal) appearing, not a gradual evolutionary development.The "missing link"will forever remain missing as it does not exist. One very certain result from accepting the theory of evolution is the degraded moral state of the world today - if indeed we are nothing more than animals we are not answerable for our actions not accountable to any higher authority.This teaching has unfortunately influenced the majority of mankind even professed Christians and the result is what we see today.It is ironic that people would then question or blame God for our present situation; the answer lies closer to home.What we believe has a bearing on the way we live our lives....after all by their fruit you recognize the tree.

Posted by Stephen on August 12,2011 | 09:42 AM

So very interesting

Posted by Sinivar on August 11,2011 | 07:47 PM

There is a very simple explanation for the appearance of "mentally modern" humans, roughly 50-70 thousand years ago, while they were "anatomically modern" for as long as 200 thousand years.

The explanation begins with observations of rare cases of human children being raised by animals, and which are generally called "feral children". They simply cannot be taught enough to become ordinary members of society. Key brain element either never grew, during earliest childhood, or atrophied.

It is known that for a child to achieve full mental development, such as is normal for most children, an environment of intense mental stimulation is required, for several of the earliest years of growth. Feral children did not have such an environment.

And neither did ANY of the original humans, 200,000 years ago. All humans at that time must have qualified as "feral". However, they still had significant intelligence and were able to create some basic things like stone tools.

Likely they also created descriptive words, even if they did not create an actual language. As the millennia passed by, more and more total things got created, and needed to be taught to their children, all of whom were still "feral".

But, about 50-70 thousand years ago, the total amount of mental stimulation given to the children of that era reached a kind of "critical mass", and the result was, quite simply, that those children became the first mentally modern humans.

As actual evidence in support of how mental stimulation can achieve a degree of mental modern-ness, even for a non-human animal, I suggest you search the Internet for "Koko the gorilla". Her abilities are limited because her total brainpower, compared to humans, is limited. But she has ENOUGH brainpower, as did all humans for more than a hundred thousand years. It merely needed enough early-life stimulation!

Posted by Vernon Nemitz on April 9,2011 | 10:42 AM

36,000 years ago, we were pretty much the same. Africans. Fascinating.

Other research shows that skin pigmentation changed in response to the need to produce vitamin D in the northern latitudes. Estimates of the time required to breed out melanin are about 20,000 years. This would have occurred between 40,000 and 20,000 years ago during the warm cycle within the Wisconsin period, before temperatures again plunged between 20,000 and 9,000 years ago.

The modern understanding of a physical "Garden of Eden" apparently existed in Northern Kurdistan where a microclimate apparently existed that was very conducive to an ideal human habitat.

There were probably a number of these isolated habitats. Surely one would have been along the southern Indian Ocean coast of Africa. Another probably occurred and established Human advancement in the Indus Valley near present day Kashmir, at the base of the Himalayan uplift. Another would have occurred on the Tamil Coast of the Indian subcontinent.

Yet another could have occurred on the Mediterranean coast of Southern Europe where the Riviera exists today. New findings of very highly advanced populations in southern Spain are indicative of a real city-state near water's edge that could be the lost Atlantis.

Likewise, the Phoenicians occupied an area of trade and advanced learning where exchange of information, material and constructive practices would have been likely to occur.

Fascinating. The repeated cycles of progression and failure of human civilization are slowly being revealed.

Ken

Posted by Ken Gill Cole on March 26,2011 | 04:11 PM

I think the 'Tubo' super volcano and its effect on food sources across the entire 'known' world played a much larger part in human migration than we suspect. Also as ANY population based on a hunter-scavenger-gatherer-fishers would have to continue to expand its area to feed the increasing population. Studies have shown that a group of 15 adults is the most psychologically stable. Women had to marry outside of the group or the group would have genetic problems that would tend to eliminate the initial group. Moving even ONE mile per year would cause the constantly extending 'family' to move the equivalent of three times around the globe in 70,000 years ... or 350,000 miles if one accepts the the life expectancy was only about age 20. Thanks for the article and the constant train of thought 'possibilities' that it brings about.

Posted by Donald G on December 4,2010 | 11:04 PM

This really is a ROTTEN article for what I would expect from the Smithsonian. The assumption of a macrocosmic manifest destiny for the human race, and the use of geographical determinism to explain any culture with less advanced technologies, are glaringly ignorant attempts at sensationalism by whoever the pop journalist is who wrote this.

Posted by Stephen Apple on July 18,2010 | 02:19 PM

Fantastic article. People, there is a long way for humans to complete and know their past. We are on the way though.
By the way, the article did not elaborate on migration to the west to areas we presently call "sub-sahara" Africa.
Where did the peple come from?

Posted by Preps Fiadzigbe on February 11,2010 | 04:56 PM

Thank you for posting this articcle, I founmd it very interesting how you used the comprehenshion of life as we know it. I appreciate you, becasue I have been looking for this article forever!

Posted by Henry Juice on January 25,2010 | 01:00 PM

Heyy, this is so interesting :P

Posted by Carley on January 25,2010 | 12:57 PM

Oh for a looking glass to view the whole of time. It may well disappoint us with it's mundane results but to have the truth would be priceless. In my book archaeologists are way under-rated in terms of their importance and relevance to modern life. We are even now in the dark ages and until the great dispersion into space occurs we will be in exactly the same position as those ancient Africans who had to leave their homes whilst holding the fate of humanity in their hands.

Posted by Steve on October 28,2009 | 07:49 AM

so I had to read this for school, I loved it, found myself reading the whole thing thoroughly, thought that you really got deep into it and touched upon many important topics, thank you

Posted by Adam on October 8,2009 | 09:29 PM

This is a fascinating conversation! Truly a gem among the dross of the blogosphere.
To Seth-I'm not sure you understand the mind of ancient human. Put yourself in their shoes. 80,000-100,000 years ago, humans lived in groups of a few hundred to maybe 1000 individuals. And there seems to have been miles between these paleolithic "villages". How many resources could they have used up? Between infant mortality, predators and all the other things that were likely to kill them before the age of thirty, they just couldn't have bred enough to imbalance their localities enough to feel the need to go elsewhere to take what others had simply for power, in my opinion. Furthermore, when they set out they couldn't have known that all those other continents were out there, just waiting to be dominated by them. Most creatures in nature have an instinct that tells them to take what they need and maybe a bit more for lean times, but very few creatures take everything they see whether they need it or not. In my opinion, ancient hominids probably fall into the former category, even if modern humans can appear to belong to the latter. I just can't see the ancient H.Sapiens saying to themselves "We've got it pretty good here, but there's more and we should own it all." I think they ran from drought/famine/name-your-disaster, or simply got curious and went trailblazing. I'm not archaeologist, paleontologist or a psychologist. I simply read a lot about a lot. For what it's worth.
To M. Nicholas-I was delighted by your insight with the cyperus. I will read up on that soon.
Finally, to everyone-Several of you are correct. Until we employ multi-disciplinarian techniques to understand archaeology (and lots of other studies), we will continue to lose sight of the whole puzzle. Kudos to people like Mr. Nicholas who aren't afraid to speak their opinion and hope that it adds to the sum of human knowledge. Maybe we can all be that generous some day.

Posted by A. Gray on May 25,2009 | 11:36 AM

I find any information from all natural sources and following the DNA trail fascinating and should be used as pieces of a puzzle to fit together the history of the earth and our human beginnings. Nothing should be taken as the whole truth but only as a piece of the puzzle which we may never put together as a whole because it is so complicated. Some people subscribe to aliens instructing the Incas and other North American Natives which I think is silly.

Posted by JoAnne Lenz on March 25,2009 | 05:00 PM

Scientist use parts of the mosaic that supports there personal belief system. A belief system that was shaped and influenced by other like minded "I can't be wrong" individuals. The truth about who we are, and whence we came is far more interesting than a few broken sea shells, or some mindless scribblings on a rock! How is it possable to make claims of such profound knowledge of human orgin's, based on what? A scribbled rock?...... Give me a break!

Posted by Iam on March 4,2009 | 02:03 PM

One thing that I cannot get to believe, that ALL of us walked out of Africa, given the proflic eating and good climate, why would we leave, for dark places unknown! the more given way would have been Driven out, by more hostile beings, fear makes the road in many a history story,chances are that we were, at one stage, all heading for Africa, from the distant, colder,birth places of our ancesters,if the giant Nova took us to the point of extinction, why is there No mention of it in our legends,and the only race that really practiced blood offerings on a grand scale were the Incas and Mayas of the New World! did they escape from Asia to the Americas, and the remments of those left, many horribly disfigured, troop off to Australia and the Java areas!,birth of the so called half man, interbreeding produced more beautiful people, but the true knit was already there, surely,as for the shellfish, they were a dammed sight more reliable than the moving herds, drawn or late in arriving to a static, waiting, very hungry, tribe,I would sooner wait by the sea, thanks, and use my net, no crops then, just the fickle reliance on a swift running beast. I am not believing any figures, or theory concerning mankind, and in any case, women set the rule, and they dont get up and drag their children across a dark and unknown place, comfort and the home fires,very hard to light, and maintain, were not to be left, lightly!. any offers against me! STAN

Posted by stanley on January 16,2009 | 10:18 PM

Well,the human migration has had an impact on our world and throughout the history people are migrating and from different people we adapt qualities which has an impact.I like the human migration cause the human migration has brought us mixture of people throughout the world.From generations to generations we are migrating and this will continue till the end of the world.

Posted by Terry on January 12,2009 | 10:52 AM

I was astounded at the age of the engraving and am very curious as to its meaning. My conjecture may challenge your assumptions but I am hoping someone may be able to help me in my inquiries. I have an Australian Federal Government award for excellence in pre-service science teaching, (so I am not just a nutter!!) but as far as I know I am completely out on my own in this specific interest. I am also contactable for the near future on the email system at Southern Cross University Lismore, Australia. The link between Cyperus (giant papyrus reed) species and abstract mathematical processing is, in my opinion, a line of enquiry which will have huge potential in understanding the developments of civilizations. The Blombos triangle figures are very possibly representational of giant cyperus reeds in cross section. However, day to day usage of cyperus for 'primitive' shelter, boat building, mat making, net making, and eventually 'paper' may have naturally induced mathematical inquiry. Cutting, collecting and bundling these triangular reeds is a lesson in hexagons, hexidecimal counting (Babylonian system), decimal counting and the square series. Paleo-botany (pollen studies) may confirm or deny this association between Cyperus sp. and the Blombos engraving. Was giant papyrus evident in the environment at the time of the engraving? Do readers know anyone who could test this hypothesis? thanking you for your interest if you have read this far, Mike Nicholas

Posted by Michael Nicholas on November 27,2008 | 06:00 PM

this is a very good thing about humans and our history

Posted by TATJANA MERRELL on November 6,2008 | 06:59 PM

C. Ehrlich & Jack: I would absolutely have to agree that the title of the article, similarly to "Eve" is somewhat of a 'misnomer'. The article is fairly lengthy, however it does not fully address the question it poses. Its really an empty sought-relief once a reader seeking an answer to that very question finishes. However, to personally address the answer to YOUR concerns, here goes: The author does briefly mention a motive for the Human Migration, and that, similarly to the motive of many other expansion based movements, is dominance. I believe the author considered the brief remark enough for a mature reader to elaborate on mentally. It should be quite obvious that early humans acknowledged the boundaries of their immediate environment. It was because of this, that they most probably had the urge to expand their civilizations. Although, and because, I'm not a historian, ill go with common sense from hereon out. These humans must have expanded on land, migrating as far out as possible, for years, until they hit the water. The water was most likely their primary area of concern. At that period in time, Humans most likely did not carry much knowledge of the sea, especially interior humankind. After crossing the sea, the process was most likely repetitive, from continent to continent. Hope I could help! :) Good luck

Posted by Seth on August 27,2008 | 10:43 PM

One possibility for the Neanderthals is their genetic material's contribution to Europeans was "flooded" out of existence because the newcomers were much more numerous. The two did interbreed, but the moderns dominated in numbers - estimated Neanderthal numbers were rather low, maybe just 1,000 at any one time. But also such a low population of large mammals would have been very vulnerable to extinction via a few bad seasons, like the peak of the last glaciation 30,000 years ago.

Posted by Adam on August 20,2008 | 07:46 PM

At one point, the author admitted that tools couldn't be known for sure because some were obviously of wood or bamboo. This type of issue has made me wonder. With all the sand in Africa and especially where civilization has built, dug, and eroded the land, how can anything be known for sure? Isn't it possible that those same bones once existed under the biggest cities - in Mesopotamia or Egypt? Maybe there were bones 100,000-200,000 years old there but everything was eroded and stamped upon. Or maybe there were bones in Greece and they were thrown into the sea from a volcano? Why Africa? There may have been very old bones in Europe but they disappeared from the Great Flood, documented everywhere. When evidence may have been destroyed, then how can anyone make a starting place? Just because the evidence was protected by jungle in Africa? It's the same issue as anything made from wood. There were houses in Egypt and Palestine and Israel made of wood but no one out here (among us readers who haven't degrees in archeology) seems to know that. I think that Stonehenge was probably just the foundation for a wooden building - there were longhouses in northern Europe then. Lots of trees. The invisible evidence is impossible to document, isn't it? So why give credit to an origin when you can't really know? I'm only a reader but doesn't this make sense? That I just don't believe anyone can say there was a starting place when they dig after the Great Flood, erosions, war, volcanos, etc. Very fascinating stuff though. Why am I here reading?

Posted by Katherine on August 15,2008 | 06:32 PM

Toba was a super volcano, one that dwarfs anything we've seen and had major impacts on the climate and fossil record. Since it occurred about 75,000 years ago, then perhaps this was the trigger for the migration. Humans were able to adapt to the sudden change in the environment and the predators of that age could not.

Posted by Dan Scarberry on July 11,2008 | 05:18 PM

very enlightening article. I'm probably somewhat of a young reader (26). Here lately, I keep thinking of how it might of been 100,000 years ago. I don't do any research on the subject, nor have it as my profession, but I do collect living fossils, if that counts. I'm looking forward to more of these articles.

Posted by M Beier on July 9,2008 | 07:47 PM

David, I don't know how easy this will be to understand, but the answer to your question is in the scientific journal "Nature." The citation for the primary paper is Nature 431:562-566 (2004). The editors' summary of it, which is easier to understand, is Nature 431:518-519 (2004).

Posted by mimi on July 5,2008 | 10:29 PM

Fascinating. More articles on this topic would be welcomed. How did racial changes occur and when? Did "modern" humans and Neanderthals inter-breed?

Posted by Ed S on July 2,2008 | 11:24 AM

I don't like margins of error in the 20000 year range as a rule; but I really, really *hate* spans like "80000 to 60000 years ago" - because the Toba eruption falls within that span. So, had humans left east Africa before or after Toba? If after, was Toba the cause? If before, did Toba wipe out the initial migration?

Posted by David Ross on July 1,2008 | 11:43 AM

C. Ehrlich: no, you didn't miss it. I read it carefully and still find myself wondering.

Posted by jack on July 1,2008 | 11:28 AM

the title is WHY the migration occurred.I cannot find any substantive answer to the question posed in the title-even though it is a rather lenghty article. Did I miss it?

Posted by c. ehrlich on June 30,2008 | 04:11 PM

Ahh, yes but Neanderthal invented the discus! All those so called 'hand axes' which would cut your hand off it you tried to use them, but which land point first nearly every time when throw.

Posted by Jon Reinertsen on June 30,2008 | 06:16 AM

is there an easily understandable way to explainn how our dna is traced back to eve in africa? i've heard and read a great deal that we date back to one single common ancestor in africa, but how is this conclusion reached?

Posted by david on June 30,2008 | 04:29 AM

Nice article, Thanks :) Johan: That's a broad brush you're tarring us with. I'm an archaeologist and I, like pretty much every single archaeologist I've ever met, would *love* to see some evidence for the aquatic ape theory of human development. We would change from being poorly-paid navvies to being minor celebrities with funding coming out of our ears if we had a blockbuster like that to work with - much like NASA finding evidence of alien intelligence, we wouldn't try to hide our cashcow from the world. How would we benefit from it? But that's the problem, isn't it? plenty of inferential, circumstantial evidence for aquatic apes and nothing concrete or evidential. If you want archaeologists to get behind the theory, you need to adorn it with a little archaeological evidence. Occam's razor can be paraphrased as "All other things being equal, the simplest solution is the best". The African Diaspora theory has MDNA and excavated evidence to support it, but there's not a scrap of direct evidence to point to the aquatic alternative - How do you apply Occam's razor when 'all things aren't equal' with the evidence? Although I agree that in the northern Americas, in recent decades, there has been a major problem with the pro-Clovis archaeologists and their closed-mindedness about older sites. They may not be silent, but they sure ain't 'the respected majority' anymore, even in the US. 'Archaeologists' are more in accord with your way of thinking than you give them credit for these days.

Posted by Spanners on June 27,2008 | 01:30 PM

I find this handy-dandy little guide to the diaspora of modern mankind to be such a crock, especially in regards to the peopling of the Americas. Haven't these "authors of the diaspora" ever heard of Pedra Furada, or the Topper Site?? If mitochondria is to be the basis of their positions-it only shows me that women got around more than men. We're all just waiting until the glorious day when a pre-hominid is discovered in the Americas !!!

Posted by E.J. Quinn on June 26,2008 | 06:58 AM

A very interesting article - thank you. I have been following this " fantastic travel story" of early man for about 10 years now. What strikes me is how dates are gradually going back in time. Recent evidence seems to be emerging that the Americas were being populated, probably by the sea route around the northern Pacific, about 40 to 60,000 years ago too. Given that man reached Australia by a sea journey of 45 miles - as you say, it seems likely that man could have reached the Americas without losing sight of land at about the same time. Do you have any comments?

Posted by Alan on June 26,2008 | 06:25 AM

Ah, those pesky shellfish. It seems that as far back as we can go, we find humans eating shellfish. The field ponders the question of precisely when humans began eating shellfish and what the effect of that was upon our population. Perhaps this is the time to look again at Occam's Razor. Occam's Razor says the simplest explanation is that we've always eaten shellfish, that it's what separates us from the other primates. There are many correlates to what happens with the application of Occam's Razor that frighten the bejeebes out of archaeologists — and with good reason, many applecarts depend on the current convoluted theory of savanna evolution, which conveniently ignores the march to the sea. Some further ponderables: evolution only happens where possible, not where necessary; which is a polite way of saying that a species cannot evolve its way out of an ecological crisis. Humans could not have evolved upright behavior because their forests were disappearing. They couldn't have forgone the protection of the forest without the protection of speed, which they sorely lacked. The problems of those pesky shellfish go on forever. Unless, of course, you apply the Razor, which makes all the problems, up to and including upright posture and migration patterns, disappear. But folks have spend a hundred years developing the statistically improbable savanna theory and they aren't about ready to give it up. That the emperor has no clothes bothers them not a whit. My advice, though, is try and figure what the odds are that the savanna theory is correct, and I think you'll find it doesn't hold water. Cheers. See you at the beach, Johan

Posted by Johan Mathiesen on June 25,2008 | 12:07 AM

In The Magazine

May 2013

View Table of Contents »

Travel with Smithsonian

Smithsonian Store

View full archiveRecent Issues

About Us

Smithsonian.com expands on Smithsonian magazine's in-depth coverage of history, science, nature, the arts, travel, world culture and technology. Join us regularly as we take a dynamic and interactive approach to exploring modern and historic perspectives on the arts, sciences, nature, world culture and travel, including videos, blogs and a reader forum.

Smithsonian.com

The Great Human Migration

Why humans left their African homeland 80,000 years ago to colonize the world

Add New Comment

Comments (36)

Most Popular

View All Most Popular »