Central Texas creek site, more than 15,000 years old, predates Clovis society
By Jennifer Welsh, LiveScience Staff Writer
LiveScience
updated 3/24/2011 4:31:34 PM ET
Humans camped by the shores of a small creek in Texas possibly even before the Clovis society, classically regarded as the first human inhabitants of the Americas, settled in the West.
The site, located in central Texas on the bank of Buttermilk Creek, has produced almost 16,000 artifacts, including stone chips and blade-like objects, in soil dating up to 15,500 years old, more than 2,000 years before the first evidence of Clovis culture. Many of the items are flakes from cutting or sharpening of tools, but the research team also found about 50 tools, including several cutting surfaces — including spear points and knives.
"The tools that we found there indicate that they were camping along the Buttermilk Creek," study researcher Mike Waters, at Texas A&M University, told LiveScience. "This probably would have been a place where they were living and conducting daily activities."
All of the objects were small and light and seem to indicate that the group led a mobile lifestyle, moving from place to place but always returning. From the wear and tear on the artifacts, some seem to have been used for cutting soft materials, like hides, while others may have been used on harder materials, like stone.
The prehistoric humans seem to have used the site for multiple centuries, as the soil where the artifacts were found was dated to between 12,800 and 15,500 years ago. "They would leave the site and come back, and each time leave behind evidence of their activities," Waters said. "They slowly but surely built up these deposits. Dating them shows they range from 15,500 years ago, then just keep going until the Clovis material."
The researchers couldn't date the material with the gold-standard method using carbon-14, since none of the artifacts had organic components, such as plant matter. The team used a different kind of dating on the soil around the artifacts, and some researchers called it into question. Extended excavation of the site could reveal carbon-dateable objects, which would confirm the age of the site.
If the dating is correct, this group would predate the Clovis society, long thought to have colonized the Americas 13,000 years ago, and could have given rise to the Clovis society. These prehistoric human societies are generally defined by the stone tools they used, the size and shape of which changed over time. Clovis used bigger blades and tools than those found at this layer of the Buttermilk site.
The site isn't the first to predate Clovis, though Waters believes his evidence is the clearest yet.
Not everyone agrees with Waters' interpretations of the findings, though. While other researchers don't question that there were probably human populations in America before Clovis, th
Tom Dillehay, a researcher at Vanderbilt University in Tennessee who wasn't involved in the study, told LiveScience that the ecological conditions at the site, including rain-swept mud and remnants of creek flooding, may have mixed the sediment layers, meaning the Clovis sediments could have been buried on top of the artifacts described by Waters, and therefore been considered more recent. The top layers are very thin.
Gary Haynes, of the University of Nevada, Reno, praised the authors for a "potentially major find" but had many of the same concerns about the research.
"They need to excavate a bigger area of the site before they can draw these kinds of conclusions," Dillehay told LiveScience. "I don't see that the data is there to present the conclusions that they are presenting."
http://www.msnbc.msn.com/id/42255086/ns/technology_and_science-science/
Showing posts with label prehistoric humans. Show all posts
Showing posts with label prehistoric humans. Show all posts
Friday, March 25, 2011
Tuesday, January 11, 2011
Researchers to drill for ancient DNA in 'hobbit' tooth
Prospects of recovering ancient DNA from boosted by study on teeth.
January 5, 2011
Nature News
By Cheryl Jones
Scientists are planning an attempt to extract DNA from the "hobbit" Homo floresiensis, the 1-meter-tall extinct distant relative of modern humans that was unearthed in Indonesia, following a study that suggests problems in standard sampling methods in ancient-DNA research could have thwarted previous efforts.
This year, geneticists at the Australian Centre for Ancient DNA (ACAD) at the University of Adelaide hope to recover DNA from a roughly 18,000-year-old H. floresiensis tooth, which was excavated in 2009 from the Liang Bua site on the Indonesian island of Flores.
The premolar has been kept cold, and has been handled as little as possible to prevent contamination with modern DNA. But little, if any, of the ancient DNA is likely to have survived the heat and moisture of the tropics, and any that has may be highly fragmented.
Tony Djubiantono, director of the Indonesian National Centre for Archaeology in Jakarta, where the tooth is held, says that developments in DNA extraction techniques could overcome previous sampling problems, and have exciting potential for understanding the evolutionary history of H. floresiensis.
If the DNA can be extracted, comparing its sequence to that of other species could settle disputes over classification. For instance, Peter Brown, a paleoanthropologist at the University of New England in Armidale, Australia, who described and named the species in 2004, is rethinking his initial classification. At first he put the species in the human genus Homo, but he now suspects that the hobbit's ancestors left Africa before Homo evolved so the species could belong to a different or new genus.
Teething troubles
Five years ago, two teams, one from ACAD and one from the Max Planck Institute of Evolutionary Anthropology in Leipzig, Germany, attempted to recover DNA from another H. floresiensis tooth excavated in 2003. Both attempts failed.
Now, a team led by Christina Adler, a geneticist at ACAD, has found that standard sampling procedures could be responsible for the failure to get DNA from the hobbit and some other ancient specimens.
Adler's team--which included some researchers involved in the original H. floresiensis DNA recovery attempt--compared the impacts of various sampling techniques on DNA from the mitochondria of 40 human specimens from around the world, which had been dated up to 7,500 years old. The results have been accepted for publication in the Journal of Archaeological Science.
Most genetics research on ancient teeth has focused on the inner tooth tissue, dentine, but Adler's team found that cementum, the coating of the root, was a richer source of DNA.
Drilling is a technique commonly used to sample teeth and bone, because it minimizes damage to the precious specimen. But Adler's team found that the heat generated at standard drill speeds of more than 1,000 revolutions per minute (RPM) destroys DNA rapidly, causing yields to be up to 30 times lower than for samples pulverized in a mill. Reducing the drill speed to 100 RPM alleviated the problem.
The Max Planck team sampled dentine from the hobbit tooth in its early attempt to recover DNA, but it is unclear what drill speed was used. And although the ACAD scientists used the lower drill speed, they also concentrated on dentine. They will target cementum in their next attempt.
Small chance
Adler says that several ancient specimens that previously failed to yield DNA might now warrant re-sampling. She is surprised that ancient-DNA researchers commonly choose to drill at high speeds for samples, because dentists have long known that this harms their patients' teeth. "This is a case of a lack of communication between two specialist fields that are both working on similar things independently," she says.
Matthew Collins, a specialist in ancient-protein analysis who is based at the University of York, UK, says that Adler's team's results will "help to ensure that we minimize the destruction of molecules during sampling of precious fossils, and potentially enable us to reach even further back in time to recover sequence information."
However, he is pessimistic about the chances of winkling DNA out of H. floresiensis, saying that the molecules are probably too fragmented owing to high temperatures at the excavation site.
But the ACAD scientists think that it is worth making an attempt on their H. floresiensis tooth. They have been encouraged by their successful extraction of DNA from a 6,000-year-old pig tooth from the site in 2007.
http://www.scientificamerican.com/article.cfm?id=researchers-to-drill-for-hobbit
January 5, 2011
Nature News
By Cheryl Jones
Scientists are planning an attempt to extract DNA from the "hobbit" Homo floresiensis, the 1-meter-tall extinct distant relative of modern humans that was unearthed in Indonesia, following a study that suggests problems in standard sampling methods in ancient-DNA research could have thwarted previous efforts.
This year, geneticists at the Australian Centre for Ancient DNA (ACAD) at the University of Adelaide hope to recover DNA from a roughly 18,000-year-old H. floresiensis tooth, which was excavated in 2009 from the Liang Bua site on the Indonesian island of Flores.
The premolar has been kept cold, and has been handled as little as possible to prevent contamination with modern DNA. But little, if any, of the ancient DNA is likely to have survived the heat and moisture of the tropics, and any that has may be highly fragmented.
Tony Djubiantono, director of the Indonesian National Centre for Archaeology in Jakarta, where the tooth is held, says that developments in DNA extraction techniques could overcome previous sampling problems, and have exciting potential for understanding the evolutionary history of H. floresiensis.
If the DNA can be extracted, comparing its sequence to that of other species could settle disputes over classification. For instance, Peter Brown, a paleoanthropologist at the University of New England in Armidale, Australia, who described and named the species in 2004, is rethinking his initial classification. At first he put the species in the human genus Homo, but he now suspects that the hobbit's ancestors left Africa before Homo evolved so the species could belong to a different or new genus.
Teething troubles
Five years ago, two teams, one from ACAD and one from the Max Planck Institute of Evolutionary Anthropology in Leipzig, Germany, attempted to recover DNA from another H. floresiensis tooth excavated in 2003. Both attempts failed.
Now, a team led by Christina Adler, a geneticist at ACAD, has found that standard sampling procedures could be responsible for the failure to get DNA from the hobbit and some other ancient specimens.
Adler's team--which included some researchers involved in the original H. floresiensis DNA recovery attempt--compared the impacts of various sampling techniques on DNA from the mitochondria of 40 human specimens from around the world, which had been dated up to 7,500 years old. The results have been accepted for publication in the Journal of Archaeological Science.
Most genetics research on ancient teeth has focused on the inner tooth tissue, dentine, but Adler's team found that cementum, the coating of the root, was a richer source of DNA.
Drilling is a technique commonly used to sample teeth and bone, because it minimizes damage to the precious specimen. But Adler's team found that the heat generated at standard drill speeds of more than 1,000 revolutions per minute (RPM) destroys DNA rapidly, causing yields to be up to 30 times lower than for samples pulverized in a mill. Reducing the drill speed to 100 RPM alleviated the problem.
The Max Planck team sampled dentine from the hobbit tooth in its early attempt to recover DNA, but it is unclear what drill speed was used. And although the ACAD scientists used the lower drill speed, they also concentrated on dentine. They will target cementum in their next attempt.
Small chance
Adler says that several ancient specimens that previously failed to yield DNA might now warrant re-sampling. She is surprised that ancient-DNA researchers commonly choose to drill at high speeds for samples, because dentists have long known that this harms their patients' teeth. "This is a case of a lack of communication between two specialist fields that are both working on similar things independently," she says.
Matthew Collins, a specialist in ancient-protein analysis who is based at the University of York, UK, says that Adler's team's results will "help to ensure that we minimize the destruction of molecules during sampling of precious fossils, and potentially enable us to reach even further back in time to recover sequence information."
However, he is pessimistic about the chances of winkling DNA out of H. floresiensis, saying that the molecules are probably too fragmented owing to high temperatures at the excavation site.
But the ACAD scientists think that it is worth making an attempt on their H. floresiensis tooth. They have been encouraged by their successful extraction of DNA from a 6,000-year-old pig tooth from the site in 2007.
http://www.scientificamerican.com/article.cfm?id=researchers-to-drill-for-hobbit
Researchers to drill for ancient DNA in 'hobbit' tooth
Prospects of recovering ancient DNA from boosted by study on teeth.
January 5, 2011
Nature News
By Cheryl Jones
Scientists are planning an attempt to extract DNA from the "hobbit" Homo floresiensis, the 1-meter-tall extinct distant relative of modern humans that was unearthed in Indonesia, following a study that suggests problems in standard sampling methods in ancient-DNA research could have thwarted previous efforts.
This year, geneticists at the Australian Centre for Ancient DNA (ACAD) at the University of Adelaide hope to recover DNA from a roughly 18,000-year-old H. floresiensis tooth, which was excavated in 2009 from the Liang Bua site on the Indonesian island of Flores.
The premolar has been kept cold, and has been handled as little as possible to prevent contamination with modern DNA. But little, if any, of the ancient DNA is likely to have survived the heat and moisture of the tropics, and any that has may be highly fragmented.
Tony Djubiantono, director of the Indonesian National Centre for Archaeology in Jakarta, where the tooth is held, says that developments in DNA extraction techniques could overcome previous sampling problems, and have exciting potential for understanding the evolutionary history of H. floresiensis.
If the DNA can be extracted, comparing its sequence to that of other species could settle disputes over classification. For instance, Peter Brown, a paleoanthropologist at the University of New England in Armidale, Australia, who described and named the species in 2004, is rethinking his initial classification. At first he put the species in the human genus Homo, but he now suspects that the hobbit's ancestors left Africa before Homo evolved so the species could belong to a different or new genus.
Teething troubles
Five years ago, two teams, one from ACAD and one from the Max Planck Institute of Evolutionary Anthropology in Leipzig, Germany, attempted to recover DNA from another H. floresiensis tooth excavated in 2003. Both attempts failed.
Now, a team led by Christina Adler, a geneticist at ACAD, has found that standard sampling procedures could be responsible for the failure to get DNA from the hobbit and some other ancient specimens.
Adler's team--which included some researchers involved in the original H. floresiensis DNA recovery attempt--compared the impacts of various sampling techniques on DNA from the mitochondria of 40 human specimens from around the world, which had been dated up to 7,500 years old. The results have been accepted for publication in the Journal of Archaeological Science.
Most genetics research on ancient teeth has focused on the inner tooth tissue, dentine, but Adler's team found that cementum, the coating of the root, was a richer source of DNA.
Drilling is a technique commonly used to sample teeth and bone, because it minimizes damage to the precious specimen. But Adler's team found that the heat generated at standard drill speeds of more than 1,000 revolutions per minute (RPM) destroys DNA rapidly, causing yields to be up to 30 times lower than for samples pulverized in a mill. Reducing the drill speed to 100 RPM alleviated the problem.
The Max Planck team sampled dentine from the hobbit tooth in its early attempt to recover DNA, but it is unclear what drill speed was used. And although the ACAD scientists used the lower drill speed, they also concentrated on dentine. They will target cementum in their next attempt.
Small chance
Adler says that several ancient specimens that previously failed to yield DNA might now warrant re-sampling. She is surprised that ancient-DNA researchers commonly choose to drill at high speeds for samples, because dentists have long known that this harms their patients' teeth. "This is a case of a lack of communication between two specialist fields that are both working on similar things independently," she says.
Matthew Collins, a specialist in ancient-protein analysis who is based at the University of York, UK, says that Adler's team's results will "help to ensure that we minimize the destruction of molecules during sampling of precious fossils, and potentially enable us to reach even further back in time to recover sequence information."
However, he is pessimistic about the chances of winkling DNA out of H. floresiensis, saying that the molecules are probably too fragmented owing to high temperatures at the excavation site.
But the ACAD scientists think that it is worth making an attempt on their H. floresiensis tooth. They have been encouraged by their successful extraction of DNA from a 6,000-year-old pig tooth from the site in 2007.
http://www.scientificamerican.com/article.cfm?id=researchers-to-drill-for-hobbit
January 5, 2011
Nature News
By Cheryl Jones
Scientists are planning an attempt to extract DNA from the "hobbit" Homo floresiensis, the 1-meter-tall extinct distant relative of modern humans that was unearthed in Indonesia, following a study that suggests problems in standard sampling methods in ancient-DNA research could have thwarted previous efforts.
This year, geneticists at the Australian Centre for Ancient DNA (ACAD) at the University of Adelaide hope to recover DNA from a roughly 18,000-year-old H. floresiensis tooth, which was excavated in 2009 from the Liang Bua site on the Indonesian island of Flores.
The premolar has been kept cold, and has been handled as little as possible to prevent contamination with modern DNA. But little, if any, of the ancient DNA is likely to have survived the heat and moisture of the tropics, and any that has may be highly fragmented.
Tony Djubiantono, director of the Indonesian National Centre for Archaeology in Jakarta, where the tooth is held, says that developments in DNA extraction techniques could overcome previous sampling problems, and have exciting potential for understanding the evolutionary history of H. floresiensis.
If the DNA can be extracted, comparing its sequence to that of other species could settle disputes over classification. For instance, Peter Brown, a paleoanthropologist at the University of New England in Armidale, Australia, who described and named the species in 2004, is rethinking his initial classification. At first he put the species in the human genus Homo, but he now suspects that the hobbit's ancestors left Africa before Homo evolved so the species could belong to a different or new genus.
Teething troubles
Five years ago, two teams, one from ACAD and one from the Max Planck Institute of Evolutionary Anthropology in Leipzig, Germany, attempted to recover DNA from another H. floresiensis tooth excavated in 2003. Both attempts failed.
Now, a team led by Christina Adler, a geneticist at ACAD, has found that standard sampling procedures could be responsible for the failure to get DNA from the hobbit and some other ancient specimens.
Adler's team--which included some researchers involved in the original H. floresiensis DNA recovery attempt--compared the impacts of various sampling techniques on DNA from the mitochondria of 40 human specimens from around the world, which had been dated up to 7,500 years old. The results have been accepted for publication in the Journal of Archaeological Science.
Most genetics research on ancient teeth has focused on the inner tooth tissue, dentine, but Adler's team found that cementum, the coating of the root, was a richer source of DNA.
Drilling is a technique commonly used to sample teeth and bone, because it minimizes damage to the precious specimen. But Adler's team found that the heat generated at standard drill speeds of more than 1,000 revolutions per minute (RPM) destroys DNA rapidly, causing yields to be up to 30 times lower than for samples pulverized in a mill. Reducing the drill speed to 100 RPM alleviated the problem.
The Max Planck team sampled dentine from the hobbit tooth in its early attempt to recover DNA, but it is unclear what drill speed was used. And although the ACAD scientists used the lower drill speed, they also concentrated on dentine. They will target cementum in their next attempt.
Small chance
Adler says that several ancient specimens that previously failed to yield DNA might now warrant re-sampling. She is surprised that ancient-DNA researchers commonly choose to drill at high speeds for samples, because dentists have long known that this harms their patients' teeth. "This is a case of a lack of communication between two specialist fields that are both working on similar things independently," she says.
Matthew Collins, a specialist in ancient-protein analysis who is based at the University of York, UK, says that Adler's team's results will "help to ensure that we minimize the destruction of molecules during sampling of precious fossils, and potentially enable us to reach even further back in time to recover sequence information."
However, he is pessimistic about the chances of winkling DNA out of H. floresiensis, saying that the molecules are probably too fragmented owing to high temperatures at the excavation site.
But the ACAD scientists think that it is worth making an attempt on their H. floresiensis tooth. They have been encouraged by their successful extraction of DNA from a 6,000-year-old pig tooth from the site in 2007.
http://www.scientificamerican.com/article.cfm?id=researchers-to-drill-for-hobbit
Wednesday, December 15, 2010
Prehistoric People Ate Each Other, Bones Show
THE GIST
Prehistoric humans, along with Neanderthals and Homo antecessor, made meals of each other, suggests new research on probable human teeth marks found on prehistoric human bones.
The findings, which will be published in the January issue of The Journal of Human Evolution, support prior theories that the first humans to re-colonize Britain after the last ice age practiced nutritional cannibalism 12,000 years ago at a site called Gough's Cave in what is now Somerset, England.
It was a survival strategy, according to authors Yolanda Fernandez-Jalvo and Peter Andrews.
"Think that a member of your group dies," Fernandez-Jalvo told Discovery News. "The body can give one day off from hunting, which was always dangerous at that time, and what to do with the dead body that may attract other dangerous carnivores that may attack the group."
"This could be a good solution," she added, reminding that cannibalism does not always mean the cannibal killed the consumed individual.
To determine what patterns humans leave behind when they chew or gnaw on bones, the researchers had four different groups of European people chew raw and cooked meat bones from various animals.
The scientists also studied bones, now in a museum, which were chewed in the 1960's by the Koi people of Namibia. The Koi tended not to cook food as much as the Europeans did, so the researchers wanted to see what kind of damage they left behind on discarded bones.
The scientists also analyzed fossilized bone collections from ancient hominid sites in Spain, the U.K. and the Caucasus region.
They determined that when humans chew and gnaw bones, a distinctive pattern is left behind. It includes bent ends of bones, puncture marks, superficial linear marks, peeling, crenulated ends and double arch punctures on the chewed edge. Not all of these features are unique to human chewing, but in combination, the researchers believe the features provide evidence for human eating.
Since bone chewing usually occurs when the consumer is trying to get at marrow and the last bit of meat, the marks can help to distinguish nutritional cannibalism from ritual de-fleshing. The findings can also reveal which animals prehistoric humans and human ancestors ate.
"Indications of Homo habilis eating hedgehog and using tools to eat them" has already been identified, Fernandez-Jalvo said.
She also said evidence suggests Neanderthals consumed marine mammals shortly after these animals gave birth, "chasing the youngest as an easy and clever strategy and avoiding the adults that were quite dangerous."
There is also evidence for an older man in China using stones to bang down on meat so it would be easier to chew.
Charles Egeland, an assistant professor of anthropology at the University of North Carolina at Greensboro, told Discovery News that "distinguishing human chewing damage from other agents (carnivores, non-human primates, non-biological processes) is extremely important."
"One of the more interesting implications of this study -- and there are many -- is that we may now have a useful set of criteria to identify meat-eating among early, pre-stone tool-using, hominids," he said.
"Somewhat ironically, this then raises the question of whether modern human chewing damage is actually the best analog for these early hominids," Egeland added. "Would chimpanzee chewing damage make a better analog?"
By Jennifer Viegas
- Human gnawing and chewing marks have been identified on human and other hominid bones.
- The findings support the idea that some prehistoric humans practiced nutritional cannibalism.
- The newly identified signature for human bone chewing is also helping to determine what animals early hominids ate.
Prehistoric humans, along with Neanderthals and Homo antecessor, made meals of each other, suggests new research on probable human teeth marks found on prehistoric human bones.
The findings, which will be published in the January issue of The Journal of Human Evolution, support prior theories that the first humans to re-colonize Britain after the last ice age practiced nutritional cannibalism 12,000 years ago at a site called Gough's Cave in what is now Somerset, England.
It was a survival strategy, according to authors Yolanda Fernandez-Jalvo and Peter Andrews.
"Think that a member of your group dies," Fernandez-Jalvo told Discovery News. "The body can give one day off from hunting, which was always dangerous at that time, and what to do with the dead body that may attract other dangerous carnivores that may attack the group."
"This could be a good solution," she added, reminding that cannibalism does not always mean the cannibal killed the consumed individual.
To determine what patterns humans leave behind when they chew or gnaw on bones, the researchers had four different groups of European people chew raw and cooked meat bones from various animals.
The scientists also studied bones, now in a museum, which were chewed in the 1960's by the Koi people of Namibia. The Koi tended not to cook food as much as the Europeans did, so the researchers wanted to see what kind of damage they left behind on discarded bones.
The scientists also analyzed fossilized bone collections from ancient hominid sites in Spain, the U.K. and the Caucasus region.
They determined that when humans chew and gnaw bones, a distinctive pattern is left behind. It includes bent ends of bones, puncture marks, superficial linear marks, peeling, crenulated ends and double arch punctures on the chewed edge. Not all of these features are unique to human chewing, but in combination, the researchers believe the features provide evidence for human eating.
Since bone chewing usually occurs when the consumer is trying to get at marrow and the last bit of meat, the marks can help to distinguish nutritional cannibalism from ritual de-fleshing. The findings can also reveal which animals prehistoric humans and human ancestors ate.
"Indications of Homo habilis eating hedgehog and using tools to eat them" has already been identified, Fernandez-Jalvo said.
She also said evidence suggests Neanderthals consumed marine mammals shortly after these animals gave birth, "chasing the youngest as an easy and clever strategy and avoiding the adults that were quite dangerous."
There is also evidence for an older man in China using stones to bang down on meat so it would be easier to chew.
Charles Egeland, an assistant professor of anthropology at the University of North Carolina at Greensboro, told Discovery News that "distinguishing human chewing damage from other agents (carnivores, non-human primates, non-biological processes) is extremely important."
"One of the more interesting implications of this study -- and there are many -- is that we may now have a useful set of criteria to identify meat-eating among early, pre-stone tool-using, hominids," he said.
"Somewhat ironically, this then raises the question of whether modern human chewing damage is actually the best analog for these early hominids," Egeland added. "Would chimpanzee chewing damage make a better analog?"
By Jennifer Viegas
Prehistoric People Ate Each Other, Bones Show
THE GIST
Prehistoric humans, along with Neanderthals and Homo antecessor, made meals of each other, suggests new research on probable human teeth marks found on prehistoric human bones.
The findings, which will be published in the January issue of The Journal of Human Evolution, support prior theories that the first humans to re-colonize Britain after the last ice age practiced nutritional cannibalism 12,000 years ago at a site called Gough's Cave in what is now Somerset, England.
It was a survival strategy, according to authors Yolanda Fernandez-Jalvo and Peter Andrews.
"Think that a member of your group dies," Fernandez-Jalvo told Discovery News. "The body can give one day off from hunting, which was always dangerous at that time, and what to do with the dead body that may attract other dangerous carnivores that may attack the group."
"This could be a good solution," she added, reminding that cannibalism does not always mean the cannibal killed the consumed individual.
To determine what patterns humans leave behind when they chew or gnaw on bones, the researchers had four different groups of European people chew raw and cooked meat bones from various animals.
The scientists also studied bones, now in a museum, which were chewed in the 1960's by the Koi people of Namibia. The Koi tended not to cook food as much as the Europeans did, so the researchers wanted to see what kind of damage they left behind on discarded bones.
The scientists also analyzed fossilized bone collections from ancient hominid sites in Spain, the U.K. and the Caucasus region.
They determined that when humans chew and gnaw bones, a distinctive pattern is left behind. It includes bent ends of bones, puncture marks, superficial linear marks, peeling, crenulated ends and double arch punctures on the chewed edge. Not all of these features are unique to human chewing, but in combination, the researchers believe the features provide evidence for human eating.
Since bone chewing usually occurs when the consumer is trying to get at marrow and the last bit of meat, the marks can help to distinguish nutritional cannibalism from ritual de-fleshing. The findings can also reveal which animals prehistoric humans and human ancestors ate.
"Indications of Homo habilis eating hedgehog and using tools to eat them" has already been identified, Fernandez-Jalvo said.
She also said evidence suggests Neanderthals consumed marine mammals shortly after these animals gave birth, "chasing the youngest as an easy and clever strategy and avoiding the adults that were quite dangerous."
There is also evidence for an older man in China using stones to bang down on meat so it would be easier to chew.
Charles Egeland, an assistant professor of anthropology at the University of North Carolina at Greensboro, told Discovery News that "distinguishing human chewing damage from other agents (carnivores, non-human primates, non-biological processes) is extremely important."
"One of the more interesting implications of this study -- and there are many -- is that we may now have a useful set of criteria to identify meat-eating among early, pre-stone tool-using, hominids," he said.
"Somewhat ironically, this then raises the question of whether modern human chewing damage is actually the best analog for these early hominids," Egeland added. "Would chimpanzee chewing damage make a better analog?"
By Jennifer Viegas
- Human gnawing and chewing marks have been identified on human and other hominid bones.
- The findings support the idea that some prehistoric humans practiced nutritional cannibalism.
- The newly identified signature for human bone chewing is also helping to determine what animals early hominids ate.
Prehistoric humans, along with Neanderthals and Homo antecessor, made meals of each other, suggests new research on probable human teeth marks found on prehistoric human bones.
The findings, which will be published in the January issue of The Journal of Human Evolution, support prior theories that the first humans to re-colonize Britain after the last ice age practiced nutritional cannibalism 12,000 years ago at a site called Gough's Cave in what is now Somerset, England.
It was a survival strategy, according to authors Yolanda Fernandez-Jalvo and Peter Andrews.
"Think that a member of your group dies," Fernandez-Jalvo told Discovery News. "The body can give one day off from hunting, which was always dangerous at that time, and what to do with the dead body that may attract other dangerous carnivores that may attack the group."
"This could be a good solution," she added, reminding that cannibalism does not always mean the cannibal killed the consumed individual.
To determine what patterns humans leave behind when they chew or gnaw on bones, the researchers had four different groups of European people chew raw and cooked meat bones from various animals.
The scientists also studied bones, now in a museum, which were chewed in the 1960's by the Koi people of Namibia. The Koi tended not to cook food as much as the Europeans did, so the researchers wanted to see what kind of damage they left behind on discarded bones.
The scientists also analyzed fossilized bone collections from ancient hominid sites in Spain, the U.K. and the Caucasus region.
They determined that when humans chew and gnaw bones, a distinctive pattern is left behind. It includes bent ends of bones, puncture marks, superficial linear marks, peeling, crenulated ends and double arch punctures on the chewed edge. Not all of these features are unique to human chewing, but in combination, the researchers believe the features provide evidence for human eating.
Since bone chewing usually occurs when the consumer is trying to get at marrow and the last bit of meat, the marks can help to distinguish nutritional cannibalism from ritual de-fleshing. The findings can also reveal which animals prehistoric humans and human ancestors ate.
"Indications of Homo habilis eating hedgehog and using tools to eat them" has already been identified, Fernandez-Jalvo said.
She also said evidence suggests Neanderthals consumed marine mammals shortly after these animals gave birth, "chasing the youngest as an easy and clever strategy and avoiding the adults that were quite dangerous."
There is also evidence for an older man in China using stones to bang down on meat so it would be easier to chew.
Charles Egeland, an assistant professor of anthropology at the University of North Carolina at Greensboro, told Discovery News that "distinguishing human chewing damage from other agents (carnivores, non-human primates, non-biological processes) is extremely important."
"One of the more interesting implications of this study -- and there are many -- is that we may now have a useful set of criteria to identify meat-eating among early, pre-stone tool-using, hominids," he said.
"Somewhat ironically, this then raises the question of whether modern human chewing damage is actually the best analog for these early hominids," Egeland added. "Would chimpanzee chewing damage make a better analog?"
By Jennifer Viegas
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