Lost Tools Reveal Early Humans' Route Out of Africa

March 2, 2009
Lost Tools Reveal Early Humans' Route Out of Africa


The peripatetic human ancestor, Homo erectus, has been in the news lately as researchers have uncovered new clues about how it walked, what tools it used, and what its hips looked like. But one mystery has persisted—how did it leave Africa, where it probably arose about 1.8 million years ago? Researchers have found fossil bones from Georgia to Java in Asia, but no bones or undisputed stone tools along the routes this early human should have trekked on its migrations out of Africa. Anyone who could draw a line on a map between east Africa and the two oldest fossil sites in western Asia could guess that H. erectus passed through Turkey, for example, but in the absence of evidence, they couldn't be sure. [...]


Now some long-awaited evidence has emerged in the form of a short trail of stone tools left behind by H. erectus as it passed through Turkey. In the current issue of Antiquity, a team of Turkish and American researchers reports about "unambiguous" stone tools and butchered animal bones dating to almost 1 million years ago. The stone tools, made mostly of milky white quartz, were found in a former lignite quarry near the village of Dursunlu in south-central Turkey. The site is relatively close to both Ubeidiya, Israel, where stone tools were left about 1.4 million years ago, and to Dmanisi, Georgia, where H. erectus bones date to 1.75 million years ago.


A team led by paleontologist Erksin Gulec of Ankara University in Turkey found 135 stone tools, including some retouched flakes and choppers. They have also found the bones of rhinoceroses, hippopotamuses, and horses with cut marks. These tools "are the first clear material traces of hominin occupation in the region," the authors write. [...]
Source Article

Lost Tools Reveal Early Humans' Route Out of Africa

Races of Neanderthals

Science News


Three Neanderthal Sub-groups Confirmed


ScienceDaily (Apr. 15, 2009) — The Neanderthals inhabited a vast geographical area extending from Europe to western Asia and the Middle East 30,000 to 100,000 years ago. Now, a group of researchers are questioning whether or not the Neanderthals constituted a homogenous group or separate sub-groups (between which slight differences could be observed).


Paleoanthropological studies based on morphological skeletal evidence have offered some support for the existence of three different sub- groups: one in Western Europe, one in southern Europe and another in the Levant.


Researchers Virginie Fabre, Silvana Condemi and Anna Degioanni from the CNRS Laboratory of Anthropology (UMR 6578) at the University of Marseille, France, have given further consideration to the question of diversity of Neanderthals by studying the genetic structure of the mitochondrial DNA (mtDNA) and by analyzing the genetic variability, modeling different scenarios. The study was possible thanks to the
publication, since 1997, of 15 mitochondrial DNA (mtDNA) sequences (the mtDNa is maternally transmitted) that originated from 12 Neanderthals.


The new study confirms the presence of three separate sub-groups and suggests the existence of a fourth group in western Asia. According to the authors, the size of the Neanderthal population was not constant over time and a certain amount of migration occurred among the sub- groups. The variability among the Neanderthal population is interpreted to be an indirect consequence of the particular climatic
conditions on their territorial extension during the entire middle Pleistocene time period.


Degioanni and colleagues obtained this result by using a new methodology derived from different biocomputational models based on data from genetics, demography and paleoanthropology. The adequacy of each model was measured by comparing the simulated results obtained using BayesianSSC software with those predicted based on nucleotide sequences.


The researchers hope that one day this methodology might be applied to questions concerning Neanderthal cultural diversity (for example the lithic industry) and to the availability of natural resources in the territory. This could provide new insights into the history and extinction of the Neanderthals.





Source

Races of Neanderthals

Bloody Stone Age: war in the Neolithic

Bloody Stone Age: war in the Neolithic


Skull from Rodmarton, Gloucestershire, with a linear fracture caused
by a severe blowThe perception that much of prehistory was relatively
peaceful is changing. New research has identified evidence of violent
assault in the Neolithic. What does this tell us about Stone Age life
as a whole? Forensic archaeologist Martin Smith explains.
Whilst many Neolithic burials have been excavated during the last 150
years, they have received only limited study. Modern analysis of these
remains by osteo-archaeologists is revealing shocking evidence for
violent assaults involving clubs, axes, and arrowshot about 5,500
years ago.Arrowheads.
Recent years have seen growing interest in conflict archaeology.
Warfare has gone from being a subject rarely mentioned by
archaeologists to one that is widely debated. Current world events
may have something to do with this, but it is also linked to advances
in our ability to recognise evidence of violence, and a drive towards
new theoretical approaches for making sense of it.


Most research of this kind has usually been concerned with more recent
periods, but lately consideration is also being given to prehistory.
In particular, we now have a growing body of evidence for aggression
between groups and individuals during the Neolithic, most of which
comes in the form of skeletal injuries. The fact that acts of violence
sometimes occurred in this period now seems indisputable. However,
assessing what this tells us about Neolithic life as a whole is
harder.


Injury probably caused by arrowshot, in a skull recovered at Littleton
Drew, Gloucestershire.Old wounds: new evidence
Many injuries to the skeleton are difficult to interpret, as there may
be a number of ways in which a particular injury could be incurred.
Fractured ribs, for example, can be sustained in various ways, mostly
through accidents such as falls. It is generally impossible to be
specific about the origin of these kinds of fractures in
archaeological bone.
Some types of injury, however, may be more consistent with a
particular cause. Fractures of the skull are a good example. Head
injuries inflicted with weapons often produce patterns of fracture
that are more easily recognised as such than wounds to other parts of
the skeleton. Improved understanding of the properties of bone
fracture has led to our recognition of a growing number of Neolithic
head injuries consistent with violence, many of which might previously
have been interpreted as damage after burial.
Such signs of violent assault are apparent throughout much of Europe,
and not least in Britain. These include a number of healed head
injuries apparently inflicted with blunt, club-like implements, as
well as unhealed fractures inflicted very close to (if not actually
at) the time of death. The latter include a mixture of sharp-force and
blunt-force trauma, possibly inflicted with stone axes.


Tip of an arrowhead embedded in part of a human vertebra from Tulloch
of Assery, Caithness. Then there are projectile wounds. This category
is particularly unequivocal where fragments of arrowheads remain
embedded in bone, although recent experimental research has revealed
that it is sometimes possible to recognise such injuries even where
the ‘murder weapon’ is no longer present. In a recent research project
examining evidence of cranial trauma, Mick Wysocki, Senior Lecturer in
Forensic Archaeology and Anthropology at the University of Central
Lancashire, and Rick Schulting, Lecturer in Scientific and Prehistoric
Archaeology from Oxford University, produced a conservative estimate
(based on the view that some examples might be misdiagnosed) that 26
out of 350 crania examined (7.4%) displayed traumatic injuries.
Pictures at Site

Bloody Stone Age: war in the Neolithic

Neanderthal

First of all I'd like to say that John Darton is a damn good writer, which is most important because this is a work of fiction. His prose flows smoothly, he's great at matching sentence structure to the emotions he's conveying, and each chapter ends with a question that keeps you reading on to the next instead of using the ol' bookmark for a break.

Having said that, if you're a real anthropology or archeology buff like I am, you may be disappointed. I myself, despite my historic bent, was only slightly disappointed, and would have given this book three and a half stars if Amazon would let me (many books I've given four stars to only deserve three and a half, and I rounded down; unfortunately for Darnton this review comes as I'm realizing how overstocked my four star reviews have become).

But, obviously from many of the reviews I see of the book on this page, most of my fellow history buffs do not agree.

The problem is that if you know alot about Neanderthals, your suspension of disbelief is seriously threatened about half-way through the book when the main characters start interacting with the neanderthals.
However, I am not altogether sure that this is a result of poor research. For most of the first half, Darnton does show a dated but still relevent knowledge of Neanderthal man as known to the educated layman, who has taken modern college level anthropology and history and who watches the occasional current PBS or Discovery Channel special on the subject (which, I might add, is the knowledge a writer needs to have and cling to when he's writing for the general public, as opposed to when he's writing for scientists). He mixes fictinional finds with actual finds well enough that he'll have you Googling them to find out which are the real.

But when the Neanderthals are actually met, the good research seems to go out the window. I suspect, however, that this is not entirely the case; Darnton seems to be using wild theories and speculations as a devise to convey an ideal and to perpetuate the myth of the noble savage. Unfortunately, his anything but mainstream theories are left unexplained and unsupported, creating either the evidence or the illusion of ignorance.

Is this the editors or the author's fault?

It's disarming to suggest agriculture before hunting and gathering. Got to explain it if you wanna have it in your book. The Neanderthals were NOT vegetarians and NOT pacifistic; got to explain why yours are if you wanna have it in your book. And if a group of neanderthals break off from the main population RECENTLY and become cannibalistic again, reverting to the VERY ritualistic practices supposedly left behind 30,000 years ago, then you gotta tell us why and how they rediscovered those. He could have at least hinted that the Neanderthals brains were able to remember their ancestor's memories to explain himself, like Aule did, if he's not going to have them find something that clues them in to their former violent selves, but the writer fails to even do that. These are only a few of the problems which irk those who know alot about neanderthals.

I realize that alot of readers get bored when the writer goes on too much about the history of characters, or explains in detail why some aspect of the thinking or philosophy in a novel is present. That's why I'm giving the author the benefit of the doubt; the editor may have dumbed it down for the "I don't want to know" public, and if he did so he should have realized that this book appeals to a diffenent niche made up of those who "have to know" in order to suspend disbelief.

To most people, it looks like the author really believes that Neanderthals could survive all this time in the mountains without being able to defend themselves in the least. Like he really believes that the killing machine that is Neanderthal could become a super-wuss despite his instinct (whether trained or experienced in fighting or not, a Neanderthal would not be clumsy and would not have the least bit of problem destroying even the greatest UFC Fighter in the world with his bare hands, unlike Darnton's unbeleivably pacifistic Neanderthals). Like he believes that agriculture really came before hunting, etc. etc.
I caution that this might not be the case, and that Darnton may have known that these things weren't true, and either originally had an explanation or purposely kept the explanation shrouded in mystery.



Did Darnton expand upon these ideas only to have an editor dumb it down for us? I really hope so, cuz other than leaving us in the dark with a broken suspension of disbelief on these topics, the guy rocks as a writer. Comment | Permalink

Neanderthal

Beyond the Gap

This book was right up my prehistoric interest alley and I've thoroughly enjoyed Turtledove's Bronze age short stories and editing, so it's no wonder I picked it up. It was a good enough read, and I got to the last page, but it took me longer than usual because the interest level just wasn't where I expected it to be.

The premise seems to be of taking a Medieval European city and placing it in North America at the end of the last Ice Age and flanking it with Cro-Magnon-like Bizogots to the north, just as the massive glacier the blocks the Berring land bridge begins to melt through. However, Turtledove and his editors and marketers never state this on the cover, flap, Preface or Introduction. To add to the confusion, Turtledove adds fantasy magic (not "Eastern" or "shamanistic" or "illusion" but downright unexplainable Dungeons and Dragons type magic) to the mix about two-thirds of the way through the book.

There's alot of walking. And alot of dialogue. And alot of pitiful mooning by an otherwise stalwart warrior about the depravity of an ex-wife he should have forgotten long ago. The idea of an enterprising nobleman who is also a formidable warrior also having the emotional fortitude of a female teenager is off-putting, and would almost make one think that Turtledove himself must not have much experience in romance. Furthermore, often the dialogue is disjointed or sophomoric, containing jokes that are either not funny or of a strange humor that's lost on this reader. Often subjects or statements presented by characters just don't ring with the truth of living dialogue.

Otherwise Turtledove's writing is excellent, and the topic interesting. I just don't see why he wanted to put it in the Ice Age if all he wanted from that era was a herd of mammoth and a small cave bear.

As other writers have said, the book finally gets going about the time it ends, and I suspect that the second installment will be better. I rarely read a sequel to a book I've only given 3 stars to, but this one might be the exception. I still believe in Turtledove, and I'm a big fan of prehistoric fiction...even if it is alternative. Besides, he never told us about the Shrine....perhaps a marketing ploy that I'll most likely fall for. But if I give this series a second chance and all that character development is proven to be for not, the second book will be lucky to get 2 stars.

Beyond the Gap

Shells Offer New Take on Human Evolution

Shells Offer New Take on Human Evolution
Anna Salleh, ABC Science Online






Prevalent Tool Material | Discovery News Video March 30, 2009 -- Analysis of complex shell tools is rewriting the history of human development.

To understand human development, archaeologists tend to analyze either fossilized human bones or stone tools. In Africa and Europe stone tools are seen to increase in complexity over the last few million years.

But in East Asia, Southeast Asia, Australia and New Guinea, stone tools don't appear to develop until the last 4000 years.

Katherine Szabo of the University of Wollongong in Australia has just taken up this issue, saying it "bears on questions of our history as a species."

Szabo explained the lack of stone tools found in these regions has led some researchers to conclude that this region was "static," with some dubbing it "culturally retarded."

Others argue that, like the hunter gatherers of today, humans in East Asia, Southeast Asia, Australia and New Guinea relied on plants, such as bamboo, rather than stone, and these aren't preserved in archaeological record.




"That may very well be true but we can't prove it," said Szabo.

She said researching shells is exciting because it can be preserved for just as long as stone in the archaeological record.

"It's not a material that anyone's looked at or that anyone particularly understands very well," said Szabo.

In published research to date, Szabo reports having excavated shell tools dating back 32,000 years from a cave site in eastern Indonesia, and comparing them with stone tools from the same cave.

"It transpired that the shell tools were in fact much more complex to produce than the stone tools," she said.

The stone tools were randomly chipped, but the shell tools had been carefully chosen and shaped.

In one case, a "cats eye" or operculum shell was flaked systematically with five blows, each one slightly overlapping with the last in a clockwise direction.


More on Page 2

Shells Offer New Take on Human Evolution

Shamans and Archaeology Options

Craft---religious--specialists marks on archaeological sites like any
other.

Shamans and Archaeology
Monday April 6, 2009


What are the archaeological signatures of shamans? An interesting paper by Christine VanPool appearing in the Journal of Anthropological Archaeology in the nearish future gives us a framework for answering that question.


Bronze Age Tanum Rock Art (Sweden), images enhanced with chalk water
Photo by JelleS


First VanPool provides a useful delineation of the cultural traits of shamans and priests, which I've used to build a couple of detailed definitions (here: Priest and Shaman). In brief, though, the way VanPool sees it, shamans and priests are two ends of a continuum of religious specialists.


What are Religious Specialists?


Religious specialists are those people in a given society who have a connection to the deities who control things humans cannot. Religious specialists are classed by dry-as-dust archaeologists as "craft specialists", and the presence of craft specialists—people with assigned part time or full time jobs including crop tending and child care and pot making and flint knapping and tending to the religious
needs of a society—is one of those characteristics of complex societies that anthropologists (and archaeologists) use to discuss how people organize themselves.


Shamans, associated with hunter-gatherer societies, may be part-time specialists, with a practice that primarily focuses on the problems of the individual. Shamans use private spaces for connecting with the underworld and actually become spiritual creatures themselves, using altered states of consciousness to connect to the other world.


Priests, on the other hand, are generally associated with agricultural societies. They have a more formalized role, and work full time at their craft; they work for the goals of the entire society. Priests follow a liturgical text and calendar, and use public spaces for publicly-attended communication with the underworld. Priests are representatives of the gods, not the gods themselves, and they don't typically use altered states of consciousness to speak to them.


VanPool points out that the two categories are created by archaeologists and anthropologists, and are not mutually exclusive in real-life applications—you can have both types of specialists in a given society. Some societies have shaman-priests who combine traits of both. Further, many native religions were greatly impacted by colonization and missionaries, creating a great loss of diversity; but
colonization, agricultural complexity and even urbanization does not necessarily entail a complete shift away from shamanism.


Identifying Religious Specialists


The Oneota Birdman or Hawkman is a half-man, half-bird image that appears in Oneota iconography, and is variously interpreted.
Image Credit: redrafted by Kris Hirst


Typically, archaeologists have used the presence of a ritual-specific artifact or a rock art drawing of an anthropomorphic creature with animal characteristics to tentatively suggest the presence of a shaman within a given society. VanPool makes a cogent argument that by now anthropologists have identified a suite of cross-cultural traits that can be identified archaeologically and thus used to confidently argue for shamanism as a practice at an archaeological site or set of sites.


These traits include evidence of the use of hallucinogens (seeds, plant residues, or identifying the specific chemicals) to achieve altered states of consciousness and entopic imagery—grids, stars, spirals—on rock art or on ceramic vessels; evidence of pilgrimages or pilgrimage routes; anthropomorphic images; animal fetishes; crystals;
drums and rattles; incense; temporary altars; effigy pipes, and the like. It is only with a combination of traits, says VanPool, that we can confidently hypothesize a shamanistic element in our archaeological past.


Further Reading


VanPool, Christine. in press. The signs of the sacred: Identifying
shamans using archaeological evidence. Journal of Anthropological
Archaeology. In press.SOURCE

Shamans and Archaeology Options

How similar was Neandertal behavior to that of modern humans? Options

Apr 6, 2009 07:30 AM in Archaeology & Paleontology


How similar was Neandertal behavior to that of modern humans?
By Kate Wong in 60-Second Science Blog


CHICAGO—Neandertals have long been portrayed as dumb brutes. But a
growing body of evidence hints that these extinct humans were much
savvier than previously thought. The results of a new study presented
here last week at the annual meeting of the Paleoanthropology Society
bolster that view, and suggest that, in fact, Neandertals acted in
much the same way as early modern humans.


To compare the behavior of Neandertals and early moderns,
paleoanthropologist Bruce Hardy of Kenyon College studied artifacts
from a site in southwestern Germany called Hohle Fels. The site
contains several levels of archaeological remains. One of these levels
dates to between 36,000 and 40,000 years ago and contains tools
manufactured in the Mousterian cultural tradition associated with
Neandertals. Another comprises items that are 33,000 to 36,000 years
old and are made in the Aurignacian style associated with early modern
humans.


What makes Hohle Fels ideal for comparing Neandertal and modern human
behavior is that both groups lived under comparable climate and
environmental conditions at this locale (cold temperatures and open
habitat). They also had the same prey animals available to them, such
as reindeer and horse.


Hardy examined the Mousterian and Aurignacian implements under a
microscope, looking at their wear patterns and searching for residues
from the substances with which the tools came into contact. He found
that although the modern humans created a larger variety of tools than
did the Neandertals, the groups engaged in mostly the same activities.
These activities include using tree resin to bind stone points to
wooden handles, employing stone points as thrusting or projectile
weapons, crafting implements from bone and wood, butchering animals
and scraping hides.


What this means, Hardy says, is that form and function are not linked.
“You don’t need a grapefruit spoon to eat a grapefruit,” he told
ScientificAmerican.com. Perhaps Neandertals did not bother inventing
additional tool types because they were able to get the job done just
fine without them.


“Neandertals stuck around for 150,000 years,” Hardy notes. “That’s not
a species that doesn’t know what it’s doing.”


Yet if Neandertals were so capable, why did they ultimately disappear?
“We don’t really know,” Hardy admits. But he doesn’t think that modern
humans killed them off. It could just be that modern humans had a
slight reproductive advantage that, over thousands of years, allowed
their population to swamp the Neandertal one.


Photo of Bruce Hardy courtesy Kenyon College at


SOURCE

How similar was Neandertal behavior to that of modern humans? Options

Ancient human unearthed in China

The remains of one of the earliest modern humans to inhabit eastern Asia have been unearthed in a cave in China. The find could shed light on how our ancestors colonised the East, a movement that is only poorly understood by anthropologists.

Researchers found 34 bone fragments belonging to a single individual at the Tianyuan Cave, near Beijing.

Details of the discovery appear in Proceedings of the National Academy of Sciences journal.

Radiocarbon dates, obtained directly from the bones, show the person lived between 42,000 and 39,000 years ago.

"For this time period, which is critical for understanding the spread of modern humans around the world, we have two well-dated human fossils from eastern Asia," said co-author Professor Erik Trinkaus, from Washington University in St Louis, US.

"We have remains from the Niah Cave from Sarawak on Borneo, and now this specimen from China. As you go west, the next specimens are from Lebanon. There's nothing in between."

Interbreeding theory

According to the "Out of Africa" theory, modern humans (Homo sapiens) evolved in East Africa and then spread out across the globe about 70,000 years ago, replacing earlier, or archaic, human populations, such as the Neanderthals, with very little, if any, interbreeding.

The Tianyuan remains display diagnostic features of modern H. sapiens. But co-author Erik Trinkaus and his colleagues argue, controversially, that the bones also display features characteristic of earlier human species, such as relatively large front teeth.

The most likely explanation, they argue, is interbreeding between early modern humans emerging from Africa and the archaic populations they encountered in Europe and Asia.

"The pattern we see across the Old World is basically a modern human in terms of its newly emerged characteristics, but also a minority of traits that are absent or lost in the earliest modern humans in East Africa," Professor Trinkaus told the BBC News website.

"The question is where did they get them from? Either they re-evolved them, which is not very likely, or, to some degree, they interbred with archaic groups.

"Sex happens. I find this neither disturbing nor surprising."

He added that evidence from the animal world suggested two closely related species, which have been separate for less than two million years, could interbreed successfully when given the opportunity to mate.

One example from the UK is the Scottish wildcat, which is being absorbed into domestic cat populations through interbreeding.

The domestic cat and the wildcat are distinct species separated by hundreds of thousands, if not millions, of years, and have very different body sizes. Despite this, pairings produce fertile, viable offspring.

Signs of disease

The view of interbreeding between Homo sapiens and archaic humans is controversial. Other palaeoanthropologists say that some of these features are simply retained from ancient African ancestors.

And most genetic evidence gathered from present-day humans does not appear to support significant interbreeding between modern humans from Africa and archaics.

The researchers' analysis of the bones has revealed several interesting details about the Tianyuan individual's lifestyle.

The person's age at death was estimated by how much the teeth had worn down. This put the individual in their late 40s or 50s.

But the lack of a pelvis among the remains means that it is not possible to say with any certainty what sex the human was.

The Tianyuan specimen shows several signs of disease. The individual had lost a number of teeth before death, not unusual considering their age.

The researchers also identified several lesions, or growths, on the leg bones, which appear to have been caused by a condition affecting the muscle attachments around both knees.

Whatever condition these were caused by, however, it does not appear to have disabled the person, because the remainder of the leg bones suggest they kept active.

The single toe bone which was unearthed seems to suggest the individual wore shoes, pushing back the earliest known evidence for footwear by about 10,000 years.

An earlier study by Professor Trinkaus shows that human small toes became weaker during the stage of prehistory known as the Upper Palaeolithic, and that this can probably be attributed to the adoption of sturdy shoes.

The invention of rugged shoes reduced humans' reliance on strong, flexile toes to grip and balance.
BBC Source

Ancient human unearthed in China

The Oldest Homo Sapiens from China Inter-bred with Erectus/Denisovan- The fossil displays mixed traits

The classical theory says that Homo sapiens emerged about 100,000 years ago in Africa and about 50-60,000 years ago started to spread out of Africa, colonizing the entire planet.

Homo sapiens would have wiped out all the pre-existent more archaic Homo species from Eurasia, and this way, our species ensured itself a huge place under the sun.

But a new research led by Erik Trinkausa, professor of anthropology at Washington University in St. Louis, Missouri and Hong Shang, a colleague in the same department at Washington University and a scholar at the Institute of Vertebrate Paleontology and Paleoanthropology at the Chinese Academy of Sciences shows that newly discovered fossil of an early Homo sapiens discovered in Beijing points out that the early dispersal of modern humans could be much more complex than first believed.

The fossils were dated 38,000 to 42,000 years ago, being the oldest Homo sapiens skeleton from eastern Eurasia, and one of the oldest human remains from the region, signaled the researchers.

The individual is basically a Homo sapiens, but he displays some archaic traits in the teeth and hand bone.

"The discovery casts further doubt on the longstanding "Out of Africa" theory which holds that when modern Homo sapiens spread eastwards from sub-Saharan Africa to Eurasia about 65,000 to 25,000 years ago, they simply replaced the native late archaic humans. The evidence has been steadily growing for some time with respect to western Eurasia to show that these modern humans interbred with local archaic humans as they spread," said Trinkaus.

"We haven't had good fossil data from eastern Eurasia to indicate whether the same thing was happening there. But this fossil, which is the first from China to be securely dated to this time period, proves that this interbreeding went on there too."

The remains were dug from the Tianyuan Cave, Zhoukoudian, near Beijing, China, in 2003, and could offer crucial clues about the replacement of archaic Homo erectus by modern humans in eastern Eurasia.

"The discovery promises to provide relevant paleontological data for our understanding of the emergence of modern humans in eastern Asia," added Trinkaus. Source Article

The Oldest Homo Sapiens from China Inter-bred with Erectus/Denisovan- The fossil displays mixed traits

Multiple out-of-Africa migrations seen for early humans

Multiple out-of-Africa migrations seen for early humans


March 23, 2009
World Science staff


Fossil evidence suggests that early, anatomically "modern" humans may have split into many isolated populations before leaving Africa in a series of migrations, scientists report.


Scientists generally believe humans evolved in Africa and from there spread out to other regions, starting over 60,000 years ago.


In new research, Gerhard Weber of the University of Vienna and colleagues used geometric patterns of fossilized skulls found in various parts of Africa to compare the diversity among early representatives of the genus Homo, the evolutionary group to which humans belong.


The researchers concluded that, rather than a single out-of-Africa dispersal, their evidence shows early modern humans in Africa were divided into different populations by the Pleistocene, the era from about two million to 11,000 years ago.


Skulls from early modern humans showed the greatest variation in shape over the last 1.8 million years, indicating that early modern humans had split into multiple, temporarily isolated populations, the researchers explained.


After that breakup there seems to have followed a complex migration pattern in which different populations left the continent left at different times, they added. They report that the skull shapes of early modern humans most closely resembled those found in later humans outside of Africa, providing a link between some isolated African populations with later migration.


Understanding the diversity of anatomically modern humans in Africa before the migrations is crucial to any analysis of modern human origins, the researchers wrote in a paper detailing their findings. "The African continent deserves more attention in the modern human origins debate," they added in the paper, to appear in this week's early online edition of the research journal Proceedings of the National Academy of Sciences.

Link

Multiple out-of-Africa migrations seen for early humans

500,000 Year Old Blade Technology!

Oldest Stone Blades Uncovered


By Ann Gibbons
ScienceNOW Daily News
2 April 2009
CHICAGO, ILLINOIS--Paleoanthropologists working in Africa have
discovered stone blades more than a half-million years old. That
pushes the date of the earliest known blades back a remarkable 150,000
years and raises a question: What human ancestor made them?


Not long ago, researchers thought that blades were so hard to make
that they had to be the handiwork of modern humans, who had evolved
the mental wherewithal to systematically strike a cobble in the right
way to produce blades and not just crude stone flakes. First, they
were thought to be a hallmark of the late Stone Age, which began
40,000 years ago. Later, blades were thought to have emerged in the
Middle Stone Age, which began about 200,000 years ago when modern
humans arose in Africa and invented a new industry of more
sophisticated stone tools. But this view has been challenged in recent
years as researchers discovered blades that dated to 380,000 years in
the Middle East and to almost 300,000 years ago in Europe, where
Neandertals may have made them (ScienceNOW, 1 December 2008).


Now it appears that more than 500,000 years ago, human ancestors
living in the Baringo Basin of Kenya collected lava stone cobbles from
a riverbed and hammered them in just the right way to produce stone
blades. Paleoanthropologists Cara Roure Johnson and Sally McBrearty of
the University of Connecticut, Storrs, recently discovered the blades
at five sites in the region, including two that date to between
509,000 and 543,000 years ago. "This is the oldest known occurrence of
blades," Johnson reported Wednesday here at the annual meeting of the
Paleoanthropology Society.


Johnson and McBrearty found the stone blades in a basalt outcrop known
as the Kapthurin Formation, including four cores from which the blades
were struck. "These assemblages would have been made by a different
species of human," Johnson said. "Who were they?" The blades come from
the same part of the formation where researchers have found two lower
jaws that have been variously described as belonging to Homo
heidelbergensis or H. rhodesiensis, human ancestors in Europe and
Africa that predate the origin of our species, H. sapiens.


Regardless of the identity of the toolmakers, other researchers say
that the discovery of blades this early suggests that these toolmakers
were capable of more sophisticated behavior than previously thought,
perhaps as a result of the last dramatic expansion of brain size in
the human lineage about 600,000 years ago. "It's reflective of a major
shift in human cognition," says Alison Brooks, a paleoanthropologist
at George Washington University in Washington, D.C.


To convince most researchers that such a dramatic breakthrough really
took place so early in human evolution, however, anthropologists will
have to find more blades this ancient, says paleoanthropologist Rick
Potts of the Smithsonian Institution in Washington, D.C. Stay tuned:
The search is already under way for more African blade runners.

Source Article with Pictures

500,000 Year Old Blade Technology!