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Can a tooth change our history of man?

December 30 2010 at 11:32 AM
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greg  (Login javajimi)
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greg) Quite a Discovery, will have to wait to see if it holds up to the Scientific scrutiny...

Can a tooth change our history of man?

Matthew Kalman
From: The Advertiser
December 30, 2010 12:01AM

Original Article
http://www.adelaidenow.com.au/can-a-tooth-change-our-history-of-man/story-e6frea6u-1225978211397
[linked image]
Professor Avi Gopher from Tel Aviv University holds an ancient tooth that was found at an archeological site in central Israel. Picture: Oded Balilty
Source: AP

THE discovery of 400,000-year-old human remains could rewrite the history of human evolution.

Until now, researchers believed that Homo sapiens, the direct descendants of modern man, evolved in Africa about 200,000 years ago and gradually migrated north, through the Middle East, to Europe and Asia.

Recently, discoveries of early human remains in China and Spain have cast doubt on the "Out of Africa" theory, but no one was certain.

But the new discovery of pre-historic human remains by Israeli explorers in a cave near Ben-Gurion airport could force scientists to rethink earlier theories.

Archaeologists from Tel Aviv University say eight human-like teeth found in the Qesem cave near Rosh Ha'Ayin - 16km from Israel's international airport - are 400,000 years old, from the Middle Pleistocene age, making them the earliest remains of Homo sapiens yet discovered anywhere in the world.

The size and shape of the teeth are very similar to those of modern man.

Until now, the earliest examples found were in Africa, dating back only 200,000 years.

Other scientists have argued human beings originated in Africa before moving to other regions 150,000 to 200,000 years ago.

Homo sapiens discovered in Middle Awash, Ethiopia, from 160,000 years ago were believed to be the oldest "modern" humans.

Other remains previously found in Israeli caves are thought to have been more recent and 80,000 to 100,000 years old.

The findings of Professor Avi Gopher and Dr Ran Barkai of the Institute of Archeology at Tel Aviv University, published in the American Journal of Physical Anthropology, suggest that modern man did not originate in Africa as previously believed, but in the Middle East.

At the same time, a separate United States study has found that Neanderthals, prehistoric cousins of humans, ate grains and vegetables as well as meat, cooking them over fire in the same way Homo sapiens did.

The Israeli Qesem cave was discovered in 2000 and has been the focus of intense study ever since.

Along with the teeth - those parts of the human skeleton that survive the longest - the researchers found evidence of a sophisticated early human society that used sharpened flakes of stone to cut meat and other prehistoric tools.

The Israeli scientists say the remains found in the cave suggested the systematic production of flint blades, the habitual use of fire, evidence of hunting, cutting and sharing of animal meat, and mining raw materials to produce flint tools from rocks below ground.

"A diversified assemblage of flint blades was manufactured and used," the Tel Aviv scientists wrote, describing the tools they found in the cave.

"Thick-edged blades, shaped through retouch, were used for scraping semi-hard materials such as wood or hide, whereas blades with straight, sharp working edges were used to cut soft tissues."

The specimens, which date back to the Middle Pleistocene era, include permanent and deciduous teeth.

They were thus placed chronologically earlier than the bulk of fossil hominid specimens previously known to be from southwest Asia.

Although none of the Qesem teeth resemble those of pre-Homo sapien Neanderthals, a few traits may suggest some affinities with members of the Neanderthal evolutionary lineage, but the balance of the evidence suggests a closer similarity with Skhul-Qafzeh dental material, also found in Israel.

In recent years, archeological evidence and human skeletons have been discovered in Spain and China that are liable to undermine the latest perception of the origins of modern man, but the findings now uncovered at Qesem are significant and invaluable, and their early age has been dubbed an extraordinary archeological discovery.

The explorers are continuing to investigate the Qesem cave and its contents, expecting to make more discoveries that would shed further light on human evolution in prehistoric times.

Separate research, published in the Proceedings of the National Academy of Sciences, challenges a prevailing theory that Neanderthals' over-reliance on meat contributed to their extinction around 30,000 years ago.

Researchers found grains from numerous plants, including a type of wild grass, as well as traces of roots and tubers, trapped in plaque build-up on fossilised Neanderthal teeth unearthed in northern Europe and Iraq.

Many of the particles "had undergone physical changes that matched experimentally-cooked starch grains, suggesting that Neanderthals controlled fire much like early modern humans," PNAS states.

Stone artefacts have not provided evidence that Neanderthals used tools to grind plants, suggesting they did not practise agriculture, but the new research indicates they cooked and prepared plants for eating, it says.

The squat, low-browed Neanderthals lived in parts of Europe, Central Asia and the Middle East for about 170,000 years but all evidence of them disappears some 28,000 years ago, their last known refuge being Gibraltar.

Why they died out is a matter of debate, because they co-existed alongside modern man.


    
This message has been edited by javajimi on Dec 30, 2010 1:05 PM
This message has been edited by javajimi on Dec 30, 2010 12:52 PM


 
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New Type of Human Discovered via Single Pinky Finger

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December 30 2010, 1:01 PM 

New Type of Human Discovered via Single Pinky Finger
Siberian fossil points to unknown migration out of Africa.

Original Article
http://news.nationalgeographic.com/news/2010/03/100325-new-human-species-x-woman-pinky-finger-denisova-dna-nature/

[linked image]
Archaeological-conference participants study Siberia's Denisova cave in 2005. Photograph courtesy Johannes Krause

Ker Than

for National Geographic News

Published March 25, 2010

A new type of prehistoric human has been discovered via DNA from a child's pinky finger found in a central Asian cave, a new study says.

"We had no inkling that this thing existed, and suddenly it's there. That in itself is a remarkable discovery," said Terry Brown, a geneticist at the University of Manchester in the U.K. and co-author of a news article released alongside the study Wednesday by the journal Nature.

If confirmed by further genetic testing, the discoverydubbed X-womanwill mark the first time that a new human species has been identified solely on the basis of DNA (quick genetics overview).

The 40,000-year-old specimen isn't good for much elseit's far too fragmentary to contain clues to the creature's skeletal structure, musculature, brainpower, or appearance, researchers say.

(Related: "Oldest Skeleton of Human Ancestor Found.")

New Human Species: Out of Africa, Quietly

The new-human discovery implies that there was a wave of human migration out of Africa, the birthplace of humanity, that was completely unknown to science.

"We think Homo erectus"an upright-walking but small-brained early human, or hominid"was the first [hominid] to leave Africa two million years ago," Brown explained. After that the record went blank until about 500,000 years ago, until now.

"This hominid seems to have left about a million years ago, so it fills in a bit of a gap," he said.

(See "Massive Genetic Study Supports 'Out of Africa' Theory.")

Uncanny X-woman

The fossilized pinky bone was discovered in a cave called Denisova in the Altay Mountains of southern Siberia, Russia.

Though the pinky's owner has been dubbed X-woman, scientists think the pinky belonged to a child between 5 and 7 years old, but experts can't tell if it was a boy or a girl.

Analysis of DNA extracted from the fossil reveals it is significantly different from the DNA of Neanderthals or of modern humans.

So far only mitochondrial DNA, or mtDNA, has been extracted. Inherited from the mother, mtDNA contains much less information than nuclear DNA, which contains most of a body's genetic information.

What mtDNA lacks in storage capacity, however, it makes up in volume. There are two copies of nuclear DNA per cell but several thousand copies of mtDNA.

For this reason, the mtDNA of the child was much easier to read, or sequence, explained Richard Green, an ancient-DNA expert at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.

A study of the child's mtDNA suggests the hominid belonged to a species that last shared a common ancestor with Neanderthals and modern humans about a million years ago. (See a photo of the first model of a Neanderthal based in part on ancient DNA evidence.)

"We don't know if the three species lived at the same place at the same time," Manchester's Brown said. "One million years is a long time, and populations of these hominids were not huge, so they could have been in different parts of Europe and Asia."

Truly a New Human Species?

X-woman appears to be a new type of human, but is it truly a new species?

Among the criteria used to determine whether different animals are distinct species are inability to interbreed, genetic dissimilarity, and anatomical variation.

It's impossible to determine whether any of these criteria apply to the Denisova child based solely on mtDNA.

For this reason, study co-leaders Johannes Krause and Svante Pääbo, also of the Max Planck Institute, are planning to harvest nuclear DNA from the fossil for analysisa painstaking process. Until then they're refusing to call X-woman a new species.

Green, who did not participate in the research, calls the team's caution "appropriate."

Because so little bone was actually discovered, scientists have no idea what the child looked like. (See "Face of Ancient Human Drawn From Hair's DNA.")

It may be possible to one day to reconstruct the Denisova child's features from its DNA, but that's a long way in the future, Green said.

 
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30,000-year-old girl's pinkie points to new early human species

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December 30 2010, 1:04 PM 

30,000-year-old girl's pinkie points to new early human species
By the CNN Wire
December 23, 2010 -- Updated 1847 GMT (0247 HKT)

Original Article
http://edition.cnn.com/2010/WORLD/asiapcf/12/23/siberia.human.ancestor.discovery/index.html?hpt=Mid

[linked image]
Excavation works inside the Denisova cave, where archaeologists found part of a finger bone in 2008
(CNN) -- An overlooked female pinkie bone put in storage after it was discovered in a Siberian cave two years ago points to the existence of a previously unknown prehistoric human species, anthropologists say.

And the lineage of that species may survive today in some people in Papua New Guinea and nearby islands, scientists say.

A report on the discovery of the finger was published in the December 23 edition of the scientific journal Nature.

Anthropologists say the 30,000- to 50,000-year-old finger is evidence of a new population of hominids they call Denisovans. The name is derived from the southern Siberian cave in which the finger bone was found.

Geneticists say the finger probably belonged to a 6- or 7-year-old girl.

"The whole story is incredible. It's like a surprising Christmas present," said Carles Lalueza Fox, a Spanish paleontologist not involved in the research who was quoted in the online article.

The 3 billion-letter nuclear genome derived from the child's finger shows that the ice-age population of early humans was more diverse than previously thought. Also, a comparison of the genome to modern humans indicates that Melanesian inhabitants of Papua New Guinea and various South Pacific islands inherited as much as 5 percent of their DNA from Denisovans.

The genome research was conducted at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.

The Denisovans, the scientists say, were more closely related to Neanderthals than modern humans. The discovery in Siberia suggests they may have lived across a wide swath of Asia and are likely to have intermingled with the ancestors of modern humans who migrated eastward from Africa.

 
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