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Monday, 1 June 2009

Neanderthals again - new facts, old theories

Today:

  1. 'You will give birth in pain': Neanderthals too
  2. Neandertal cannibalism? Maybe not
  3. How similar was Neandertal behavior to that of modern humans?
  4. Three Subgroups of Neanderthals Identified
Short stories:
  1. Cambodia: Dinosaur images noticed in temple ruin
  2. Hobbit brain small, but organized for complex intelligence
  3. Oldest Stone Blades Uncovered
Ok, today's post is oriented toward one idea-that we still largely underestimate our ancestors. And this is obviously wrong. The main dish are the Neanderthals and all those new facts we know about them. For dessert are the short stories. I'd like to highlight the dinosaur story since it's very curious. But the moral from this post is that we're simply starting to understand our ancestors-who they were, how smart they were and so on. And honestly, I don't think the main problem is that we don't have enough facts-the problem is inertia in archeology and anthropology- they simply won't give up the image of the stupid Neanderthal and the smart Homo Sapience-the survivor. In the end-Neanderthals could have mass-suicided, because they felt that's what gods told them. Or they could have been eaten by the dinosaurs who found them more nutritious than humans. There are so many possibilities, can't we please focus on facts and stop reciting old theories as they are settled. They are not!
Enjoy!

'You will give birth in pain': Neanderthals too


April 21st, 2009
(PhysOrg.com) -- Researchers from the University of California at Davis (USA) and the Max Planck Institute for Evolutionary Anthropology in Leipzig (Germany) present a virtual reconstruction of a female Neanderthal pelvis from Tabun (Israel). Although the size of Tabun’s reconstructed birth canal shows that Neanderthal childbirth was about as difficult as in present-day humans, the shape indicates that Neanderthals retained a more primitive birth mechanism than modern humans.

The virtual reconstruction of the pelvis from Tabun is going to be the first of its kind to be available for download on the internet for everyone interested in the evolution of humankind.

in humans is more complicated than in other . Unlike the situation in great apes, human babies are about the same size as the birth canal, making passage difficult. The birth mechanism, a series of rotations the baby must undergo to successfully navigate its mother’s birth canal, distinguishes humans not only from great apes but also from lesser apes and monkeys.

It has been difficult to trace the evolution of human childbirth because the pelvic skeleton, which forms the margins of the birth canal, tends to survive poorly in the fossil record. Only three fossil female individuals preserve fairly complete birth canals, and they all date to earlier phases of human evolution.

Tim Weaver of the University of California (Davis, USA) and Jean-Jacques Hublin, director at the Max Planck Institute for Evolutionary Anthropology in Leipzig (Germany) now present a virtual reconstruction of a female Neanderthal pelvis from Tabun (Israel). The size of Tabun’s reconstructed birth canal shows that Neanderthal childbirth was about as difficult as in present-day humans. However, its shape indicates that Neanderthals retained a more primitive birth mechanism than modern humans, without rotation of the baby’s body.

A significant shift in childbirth apparently happened quite late in human evolution, during the last 400,000 - 300,000 years. Such a late shift underscores the uniqueness of human childbirth and the divergent evolutionary trajectories of and the lineage leading to present-day humans. source

My comment: This is really fascinating. With every day going by, we find how similar we are to the Neanderthals. And I don't get why they're calling their way of giving birth more primitive, when it could be simply different. I'm sure it was the most adequate way for their physiology- it's the idea of evolutions after all. In any case, this is extremely interesting result. And it brings me back to the idea to clone a Neanderthal. If we could persuade a family to grow the baby in normal human environment, this will be the biggest test for our egos. But that is very unlikely to happen.

Apr 2, 2009 06:50

Neandertal cannibalism? Maybe not

By Kate Wong
CHICAGO—Scientists have long argued that Neandertal remains from the site of Krapina in northern Croatia exhibit evidence of cannibalism. The fragmentary nature of the bones, along with cut marks on a number of fragments, were said to be signs that our closest relatives feasted on one another. But a new study suggests that the nicks seem to be the result of much more recent handiwork.

Paleoanthropologist and archaeologist Jörg Orschiedt of the University of Hamburg in Germany reported yesterday at the annual meeting of the Paleoanthropology Society here that cut marks in the Krapina fossils he studied are randomly distributed and did not necessarily occur in spots that would permit de-fleshing (such as where muscles attach to bones). What's more, the scratches varied – some were shallow and others deep.

An alternative explanation to cannibalism dawned on him as he sifted through photos of the bones. Specifically, he came across a picture of a bone fragment with the letter F for femur (the thighbone) scrawled on it. It turns out the bone was mislabeled—it was actually part of a shinbone, not a thighbone—but what caught Orschiedt’s eye was that the cut marks interrupted the F. He concluded that the scratches were likely made inadvertently by a researcher—possibly during measurement of the bone with sharp instruments—after the bone was labeled, probably in the early 1900s.

One Krapina specimen that Orschiedt believes does have genuinely ancient cut marks is a famous partial skull known as the C skull. These nicks, which appear in the center of the forehead, are encrusted with minerals that could only have accumulated long ago.

As for the fact that many of the Krapina Neandertal bones are broken to bits, which investigators have long attributed to the hominids extracting nutritious marrow, Orschiedt believes that hungry carnivores were responsible for much of the damage. He also thinks that as the roof of the rock shelter crumbled over time, falling rocks smashed the bones.

If Orschiedt is right, what is arguably the most famous example of cannibalism among our closest relatives can no longer be held up as such. source
My comment: It's interesting that we imply cannibalism is bad because we've seen it only in primitive tribes. Too bad I don't know how common it is with predators, but it appears that primate eat each other, though I couldn't find the rate of cannibalism. In any case, it seems to me little premature to put emotional charge on the issue even if it sounds quite disgusting now, 1000-1500 years ago, people sometimes ate organs of their enemies (or used their skulls as a cup, for example). That's why, as we don't know the rate at which those people ate each other, and the reason they did it, it's hard to say whether it was primitivism or ritual.
Apr 6, 2009 07:30 AM

How similar was Neandertal behavior to that of modern humans?

By Kate Wong
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. Perhaps Neandertals did not bother inventing additional tool types because they were able to get the job done just fine without them.

Yet if Neandertals were so capable, why did they ultimately disappear? “We don’t really know,” Hardy admits. source
My comment: I can add another idea-maybe they had more tools, we just haven't found them. Or they compensated the lack of variety of form with variety of use. Obviously I'm on their side, I just think it's pretty obvious today that we had way too many prejudices towards Neanderthals and maybe it's time to take an impartial look on the situation.

Three Subgroups of Neanderthals Identified

By Clara Moskowitz

14 April 2009

We tend to think of Neanderthals as one species of cavemen-like creatures, but now scientists say there were actually at least three different subgroups of Neanderthals.

Using computer simulations to analyze DNA sequence fragments from 12 Neanderthal fossils, researchers found that the species can be separated into three, or maybe four, distinct genetic groups.

The evidence points to a subgroup of Neanderthals in Western Europe, another in Southern Europe near the Mediterranean, a third in Eastern Europe and the Middle East, and possibly a fourth in Western Asia. These groups have been postulated before, but this is the first study analyzing DNA data to look for genetic variations differentiating the subgroups.

Neanderthals are a hominid species that lived between about 130,000 and 30,000 years ago. They coexisted with humans for a while, and may even have interbred with us.

The researchers tested various hypotheses, including that all Neanderthals belonged to a single homogeneous population, or that Neanderthals could be divided into two, three, or more subgroups. They found that the three- and four-group model best fit the data by accounting for the genetic discrepancies seen in the samples.

The authors admit that their categorization is based on limited data, since they only have fragments of mitochondrial DNA sequences from a small sample of individuals.

Princeton University paleoanthropologist Alan Mann agreed, and said it's too early to draw bounds around sub-populations because we don't have any data from individuals outside of the bounds, such as from Neanderthals in Africa or Southeast Asia.

In the future, the researchers would like to compare their genetic data to what is known about physical distinctions among Neanderthals from different regions, as well as cultural differences, such as unique tool use among various populations. source

My comment: Isn't interesting that the different groups resemble the different Homo Sapience groups?Ok, I'm just making this up, but I find it quite interesting .So, they were 3-4 groups. Next thing to find out what were the social differences between those groups and their intellectual level.

Short stories:


Cambodia: Dinosaur images noticed in temple ruin
15-2-2009
Michael Cohen m.cohen@allnewsweb.com
Conventional science has it that the dinosaurs were wiped out many millions of years ago either as the result of climate change or a meteorite hitting earth. Some researchers, however, claim that dinosaurs might have continued to roam remote parts of the earth as recently as a few hundred years ago. A few even claim that there might be some small populations of dinosaurs, otherwise believed to be extinct, surviving in the world’s most isolated forests.
A reader has sent to All News Web these photos of the stunning Ta Prohm Temple deep in the jungles of Cambodia.This temple is the work of the remarkable Khmer civilization which lasted from the 800’s AD until the 1400’s AD.
The temple is covered with the most intricate of carvings. The reader who was visiting the area noticed very distinct and clear images that seem to depict a Stegosaurus (pictured above), indicating that this creature might well have survived up until the Khmer era in the region. One expert on Khmer ruins has told us that it is unlikely that these images are a recent addition to the temple.
The stegosaurus (pictured below) was a spectacular beast best known for the row of kite shaped plates that ran along the length of its back. According to conventional science this species existed in North America and died out around 155 million years ago. Villagers in the vicinity of the temple are said to retain traditions of this animal existing until fairly recent times. source

Oldest Stone Blades Uncovered

By Ann Gibbons, 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.

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.

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. source

Hobbit brain small, but organized for complex intelligence

CHICAGO — In the strange and contentious world of fossil hobbits, a chimp-sized brain may boast humanlike powers. An analysis of the inner surface of an 18,000-year–old skull assigned to Homo floresiensis, a species also known as hobbits, indicates that this tiny individual possessed a brain blessed with souped-up intellectual capacities needed for activities such as making stone tools, says anthropologist Dean Falk of Florida State University in Tallahassee.

Even as H. floresiensis evolved a relatively diminutive brain, the species underwent substantial neural reorganization that allowed its members to think much like people do, Falk contended.

Falk compared a cast of the cranium’s inner surface, or endocast, obtained from the partial hobbit skeleton LB1 to endocasts from both modern humans and from other fossil skulls in the human evolutionary family, called hominids for short. These casts bring into relief impressions made by various anatomical landmarks on the brain’s surface.

“LB1 reveals that significant cortical reorganization was sustained in ape-sized brains of at least one hominid species,” Falk said.

Evidence has shown that some hominid species experienced marked increases in brain size over time, but that neural reorganization took center stage for others, including hobbits, she proposes. Currently, no one knows whether a large-bodied or small-bodied species gave rise to hobbits, whose fossils have been found on the Indonesian island of Flores.

Although small in size, LB1’s endocast displays a humanlike shape, Falk asserted. An endocast from Australopithecus africanus, a roughly 3-million-year–old South African hominid species, looks similar to that of LB1, Falk asserted.

Yet unlike the earlier A. africanus, LB1 possessed a set of brain features that other researchers have implicated in complex forms of thinking by people today, she said. These features ran from the back to the front of the brain. Traits such as expanded frontal lobes and enlarged regions devoted to integrating information from disparate areas would have supported creative and innovative thinking, in Falk’s view.

No signs of disease or abnormal development appear on LB1’s brain surface, she noted. Some researchers argue that the specimen came from a modern human who had some type of growth disorder. source

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