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Human domestication of soybeans is thought to have first occurred in central China some 3,000 years ago, but archaeologists now suggest that cultures in even earlier times and in other locations adopted the legume (Glycine max).
Comparisons of 949 charred soybean samples from 22 sites in northern China, Japan and South Korea -- found in ancient households including hearths, flooring and dumping pits -- with 180 modern charred and unburned samples were detailed in the Nov. 4 edition of the online journal PLoS ONE, a publication of the Public Library of Science.
The findings, say lead author Gyoung-Ah Lee, an archaeologist at the University of Oregon, add a new view to long-running assumptions about soybean domestication that had been based on genetic and historical records.
"Preserved beans have been carbonized, and that distorts the sizes," Lee said. "So we experimented with modern soybeans, charring them to compare them with historical samples. All the different sizes and shapes of soybeans may indicate different efforts in different times by different cultural groups in different areas."
Experts argue that larger beans reflect domestication, but the transition zone between smaller wild-type soybeans and larger hybridized versions is not understood, Lee said. Small-seeded soybeans indicating wild-type soybeans date to 9,000 years ago. Historical evidence to date shows a close relationship between soybeans and use in China during the Zhou Dynasty, about 2,000 years ago. The new study moves domestication back to perhaps 5,500 years ago.
"Soybeans appeared to be linked to humans almost as soon as villages were established in northern China," said co-author Gary Crawford, a professor of anthropology at the University of Toronto Mississauga, in a news release. "Soybean seems to be a plant that does well in human-impacted habitats. In turn, humans began to learn how tasty soybean was and how useful it was."
Today, of course, soybeans are used as livestock feed and to make cooking oil, tofu, tempeh, edamame and protein powder for human consumption.
The new archaeological evidence, Lee says, should be a springboard for archaeologists, crop scientists and plant geneticists to collaborate on understanding cultural contributions, which may lead them to better soybean characteristics. Cultural knowledge, she said, could fill in gaps that relate to domestication and genetic changes of the legume.
"I think one contribution that archaeologists can make is how peoples in ancient times contributed to our heritage of this viable crop and how we can trace their efforts and the methods to help guide us to make even better crops today," Lee said.
In Lee's homeland of South Korea, the research team uncovered evidence for a cultural selection for larger sized soybeans at 3,000 years ago. The evidence for such dating, which also surfaced in Japan, indicates that the farming of soybeans was much more widespread in times much earlier than previously assumed, researchers concluded.
Monday, November 21, 2011
Monday, November 14, 2011
Ancient bronze artifact from East Asia unearthed at Alaska archaeology site
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Artifact resembles small, broken buckle, could have been horse ornament
A team of researchers led by the University of Colorado Boulder has discovered the first prehistoric bronze artifact made from a cast ever found in Alaska, a small, buckle-like object found in an ancient Eskimo dwelling and which likely originated in East Asia.
The artifact consists of two parts -- a rectangular bar, connected to an apparently broken circular ring, said CU-Boulder Research Associate John Hoffecker, who is leading the excavation project. The object, about 2 inches by 1 inch and less than 1 inch thick, was found in August by a team excavating a roughly 1,000-year-old house that had been dug into the side of a beach ridge by early Inupiat Eskimos at Cape Espenberg on the Seward Peninsula, which lies within the Bering Land Bridge National Preserve.
Both sections of the artifact are beveled on one side and concave on the other side, indicating it was manufactured in a mold, said Hoffecker, a fellow at CU-Boulder's Institute of Arctic and Alpine Research. A small piece of leather found wrapped around the rectangular bar by the research team yielded a radiocarbon date of roughly A.D. 600, which does not necessarily indicate the age of the object, he said.
"I was totally astonished," said Hoffecker. "The object appears to be older than the house we were excavating by at least a few hundred years."
Hoffecker and his CU-Boulder colleague Owen Mason said the bronze object resembles a belt buckle and may have been used as part of a harness or horse ornament prior to its arrival in Alaska. While they speculated the Inupiat Eskimos could have used the artifact as a clasp for human clothing or perhaps as part of a shaman's regalia, its function on both continents still remains a puzzle, they said.
Since bronze metallurgy from Alaska is unknown, the artifact likely was produced in East Asia and reflects long-distance trade from production centers in either Korea, China, Manchuria or southern Siberia, according to Mason. It conceivably could have been traded from the steppe region of southern Siberia, said Hoffecker, where people began casting bronze several thousand years ago.
Alternatively, some of the earliest Inupiat Eskimos in northwest Alaska -- the direct ancestors of modern Eskimos thought to have migrated into Alaska from adjacent Siberia some 1,500 years ago -- might have brought the object with them from the other side of the Bering Strait. "It was possibly valuable enough so that people hung onto it for generations, passing it down through families," said Mason, an INSTAAR affiliate and co-investigator on the Cape Espenberg excavations.
The Seward Peninsula is a prominent, arrowhead-shaped land mass that abuts the Bering Strait separating Alaska from Siberia. The peninsula was part of the Bering Land Bridge linking Asia and North America during the last ice age when sea level had dropped dramatically, and may have been used by early peoples as a corridor to migrate from Asia into the New World some 14,000 years ago.
The artifact was discovered in August by University of California, Davis, doctoral student Jeremy Foin under 3 feet of sediment near an entryway to a house at Cape Espenberg. Other project members included Chris Darwent of UC Davis, Claire Alix of the University of Paris, Nancy Bigelow of the University of Alaska Fairbanks, Max Friesen of the University of Toronto and Gina Hernandez of the National Park Service.
"The shape of the object immediately caught my eye," said Foin, who spotted the soil-covered artifact in an archaeological sifting screen. "After I saw that it clearly had been cast in a mold, my first thought was disbelief, quickly followed by the realization that I had found something of potentially great significance."
The CU-led excavations are part of a National Science Foundation-funded project designed to study human response to climate change at Cape Espenberg from A.D. 800 to A.D. 1400, a critical period of cultural change in the western Arctic, said Mason. Of particular interest are temperature and environmental changes that may be related to Earth's Medieval Warm Period that lasted from about A.D. 950 to 1250.
"That particular time period is thought by some to be an analog of what is happening to our environment now as Earth's temperatures are rising," said Mason. "One of our goals is to find out how these people adapted to a changing climate through their subsistence activities."
The Cape Espenberg beach ridges, wave-swept deposits made of sand and sediment running parallel to the shoreline that were deposited over centuries, often are capped by blowing sand to form high dunes. The Cape Espenberg dwellings were dug into the dunes and shored up with driftwood and occasional whale bones.
The team is examining the timing and formation of the beach ridges as well as the contents of peat and pond sediment cores to help them reconstruct the sea-level history and the changing environment faced by Cape Espenberg's settlers. Information on past climates also is contained in driftwood tree rings, and the team is working with INSTAAR affiliate Scott Elias, a University of London professor and expert on beetle fossils, who is helping the team reconstruct past temperatures at Cape Espenberg.
While the hunting of bowhead whales was a way of life for Inupiat Eskimos at Barrow and Point Hope in northwestern Alaska 1,000 years ago, it is still not clear if the Cape Espenberg people were whaling, said Mason. While whale baleen -- a strong, flexible material found in the mouths of whales that acts as a food filter -- and a variety of whale bones have been found during excavations there, the sea offshore is extremely shallow and some distance from modern whale migration routes. However, there is evidence of fishing and seal and caribou hunting by the group, he said.
The Inupiat Eskimos are believed to have occupied Cape Espenberg from about A.D. 1000 until the mid-1800s, said Hoffecker. They are part of the indigenous Eskimo culture that lives in Earth's circumpolar regions like Alaska, Siberia and Canada.
The Cape Espenberg site has yielded a treasure trove of several thousand artifacts, including sealing harpoons, fishing spears and lures, a copper needle, slate knives, antler arrow points, a shovel made from a walrus scapula, a beaver incisor pendant, ceramics, and even toy bows and toy harpoons. The bronze artifact unearthed in August is currently under study by prehistoric metallurgical expert and Purdue University Assistant Professor H. Kory Cooper.
Artifact resembles small, broken buckle, could have been horse ornament
A team of researchers led by the University of Colorado Boulder has discovered the first prehistoric bronze artifact made from a cast ever found in Alaska, a small, buckle-like object found in an ancient Eskimo dwelling and which likely originated in East Asia.
The artifact consists of two parts -- a rectangular bar, connected to an apparently broken circular ring, said CU-Boulder Research Associate John Hoffecker, who is leading the excavation project. The object, about 2 inches by 1 inch and less than 1 inch thick, was found in August by a team excavating a roughly 1,000-year-old house that had been dug into the side of a beach ridge by early Inupiat Eskimos at Cape Espenberg on the Seward Peninsula, which lies within the Bering Land Bridge National Preserve.
Both sections of the artifact are beveled on one side and concave on the other side, indicating it was manufactured in a mold, said Hoffecker, a fellow at CU-Boulder's Institute of Arctic and Alpine Research. A small piece of leather found wrapped around the rectangular bar by the research team yielded a radiocarbon date of roughly A.D. 600, which does not necessarily indicate the age of the object, he said.
"I was totally astonished," said Hoffecker. "The object appears to be older than the house we were excavating by at least a few hundred years."
Hoffecker and his CU-Boulder colleague Owen Mason said the bronze object resembles a belt buckle and may have been used as part of a harness or horse ornament prior to its arrival in Alaska. While they speculated the Inupiat Eskimos could have used the artifact as a clasp for human clothing or perhaps as part of a shaman's regalia, its function on both continents still remains a puzzle, they said.
Since bronze metallurgy from Alaska is unknown, the artifact likely was produced in East Asia and reflects long-distance trade from production centers in either Korea, China, Manchuria or southern Siberia, according to Mason. It conceivably could have been traded from the steppe region of southern Siberia, said Hoffecker, where people began casting bronze several thousand years ago.
Alternatively, some of the earliest Inupiat Eskimos in northwest Alaska -- the direct ancestors of modern Eskimos thought to have migrated into Alaska from adjacent Siberia some 1,500 years ago -- might have brought the object with them from the other side of the Bering Strait. "It was possibly valuable enough so that people hung onto it for generations, passing it down through families," said Mason, an INSTAAR affiliate and co-investigator on the Cape Espenberg excavations.
The Seward Peninsula is a prominent, arrowhead-shaped land mass that abuts the Bering Strait separating Alaska from Siberia. The peninsula was part of the Bering Land Bridge linking Asia and North America during the last ice age when sea level had dropped dramatically, and may have been used by early peoples as a corridor to migrate from Asia into the New World some 14,000 years ago.
The artifact was discovered in August by University of California, Davis, doctoral student Jeremy Foin under 3 feet of sediment near an entryway to a house at Cape Espenberg. Other project members included Chris Darwent of UC Davis, Claire Alix of the University of Paris, Nancy Bigelow of the University of Alaska Fairbanks, Max Friesen of the University of Toronto and Gina Hernandez of the National Park Service.
"The shape of the object immediately caught my eye," said Foin, who spotted the soil-covered artifact in an archaeological sifting screen. "After I saw that it clearly had been cast in a mold, my first thought was disbelief, quickly followed by the realization that I had found something of potentially great significance."
The CU-led excavations are part of a National Science Foundation-funded project designed to study human response to climate change at Cape Espenberg from A.D. 800 to A.D. 1400, a critical period of cultural change in the western Arctic, said Mason. Of particular interest are temperature and environmental changes that may be related to Earth's Medieval Warm Period that lasted from about A.D. 950 to 1250.
"That particular time period is thought by some to be an analog of what is happening to our environment now as Earth's temperatures are rising," said Mason. "One of our goals is to find out how these people adapted to a changing climate through their subsistence activities."
The Cape Espenberg beach ridges, wave-swept deposits made of sand and sediment running parallel to the shoreline that were deposited over centuries, often are capped by blowing sand to form high dunes. The Cape Espenberg dwellings were dug into the dunes and shored up with driftwood and occasional whale bones.
The team is examining the timing and formation of the beach ridges as well as the contents of peat and pond sediment cores to help them reconstruct the sea-level history and the changing environment faced by Cape Espenberg's settlers. Information on past climates also is contained in driftwood tree rings, and the team is working with INSTAAR affiliate Scott Elias, a University of London professor and expert on beetle fossils, who is helping the team reconstruct past temperatures at Cape Espenberg.
While the hunting of bowhead whales was a way of life for Inupiat Eskimos at Barrow and Point Hope in northwestern Alaska 1,000 years ago, it is still not clear if the Cape Espenberg people were whaling, said Mason. While whale baleen -- a strong, flexible material found in the mouths of whales that acts as a food filter -- and a variety of whale bones have been found during excavations there, the sea offshore is extremely shallow and some distance from modern whale migration routes. However, there is evidence of fishing and seal and caribou hunting by the group, he said.
The Inupiat Eskimos are believed to have occupied Cape Espenberg from about A.D. 1000 until the mid-1800s, said Hoffecker. They are part of the indigenous Eskimo culture that lives in Earth's circumpolar regions like Alaska, Siberia and Canada.
The Cape Espenberg site has yielded a treasure trove of several thousand artifacts, including sealing harpoons, fishing spears and lures, a copper needle, slate knives, antler arrow points, a shovel made from a walrus scapula, a beaver incisor pendant, ceramics, and even toy bows and toy harpoons. The bronze artifact unearthed in August is currently under study by prehistoric metallurgical expert and Purdue University Assistant Professor H. Kory Cooper.
Thursday, November 3, 2011
Research reveals autistic individuals are in fact superior in multiple areas
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We must stop considering the different brain structure of autistic individuals to be a deficiency, as research reveals that many autistics – not just "savants" – have qualities and abilities that may exceed those of people who do not have the condition, according to a provocative article published today in Nature by Dr. Laurent Mottron at the University of Montreal's Centre for Excellence in Pervasive Development Disorders. "Recent data and my own personal experience suggest it's time to start thinking of autism as an advantage in some spheres, not a cross to bear," Mottron said.
Mottron's research team has strongly established and replicated the abilities and sometimes superiorities of autistics in multiple cognitive operations such as perception and reasoning, as have others. His group includes several autistics, and one of them, Michelle Dawson, is a particular success. Dawson makes major contributions to our understanding of the condition through her work and her judgment. "Michelle challenged my scientific perception of autism," Mottron explained. Dawson's insight is the interpretation of autistic strengths as the manifestation of authentic intelligence rather than a kind of trick of the brain that allows them to mindlessly perform intelligent tasks. "It's amazing to me that for decades scientists have estimated the magnitude of mental retardation based on the administration of inappropriate tests, and on the misinterpretation of autistic strengths," Mottron added.
"We coined a word for that: normocentrism, meaning the preconception you have that if you do or are something, it is normal, and if autistic do or have it, it is abnormal," Mottron said. He points out that there's a strong motivation for this perception, as it is the standard rhetoric of fund raising and grant applications, but that it comes at a cost in terms of how autistics are designated in social discourse. "While state and nonprofit funding is important for advancing our understanding of the condition, it's exceptional that these tools are used to work towards goals identified by the autistic community itself," Mottron said, lamenting the fact that many autistics end up working repetitive, menial jobs, despite their intelligence and aptitude to make much more significant contributions to society. "Dawson and other autistic individuals have convinced me that, in many instances, people with autism need more than anything opportunities, frequently support, but rarely treatment," Mottron said. "As a result, my lab and others believe autism should be described and investigated as an accepted variant within human species, not as a defect to be suppressed."
Laurent Mottron's article claims that science should do its part to bring back autistics as members of the human community. His paper goes into more detail about the specific abilities of some autistic individuals, provides a range of real world examples, and offers some personal insights into his collaborations with Michelle Dawson.
We must stop considering the different brain structure of autistic individuals to be a deficiency, as research reveals that many autistics – not just "savants" – have qualities and abilities that may exceed those of people who do not have the condition, according to a provocative article published today in Nature by Dr. Laurent Mottron at the University of Montreal's Centre for Excellence in Pervasive Development Disorders. "Recent data and my own personal experience suggest it's time to start thinking of autism as an advantage in some spheres, not a cross to bear," Mottron said.
Mottron's research team has strongly established and replicated the abilities and sometimes superiorities of autistics in multiple cognitive operations such as perception and reasoning, as have others. His group includes several autistics, and one of them, Michelle Dawson, is a particular success. Dawson makes major contributions to our understanding of the condition through her work and her judgment. "Michelle challenged my scientific perception of autism," Mottron explained. Dawson's insight is the interpretation of autistic strengths as the manifestation of authentic intelligence rather than a kind of trick of the brain that allows them to mindlessly perform intelligent tasks. "It's amazing to me that for decades scientists have estimated the magnitude of mental retardation based on the administration of inappropriate tests, and on the misinterpretation of autistic strengths," Mottron added.
"We coined a word for that: normocentrism, meaning the preconception you have that if you do or are something, it is normal, and if autistic do or have it, it is abnormal," Mottron said. He points out that there's a strong motivation for this perception, as it is the standard rhetoric of fund raising and grant applications, but that it comes at a cost in terms of how autistics are designated in social discourse. "While state and nonprofit funding is important for advancing our understanding of the condition, it's exceptional that these tools are used to work towards goals identified by the autistic community itself," Mottron said, lamenting the fact that many autistics end up working repetitive, menial jobs, despite their intelligence and aptitude to make much more significant contributions to society. "Dawson and other autistic individuals have convinced me that, in many instances, people with autism need more than anything opportunities, frequently support, but rarely treatment," Mottron said. "As a result, my lab and others believe autism should be described and investigated as an accepted variant within human species, not as a defect to be suppressed."
Laurent Mottron's article claims that science should do its part to bring back autistics as members of the human community. His paper goes into more detail about the specific abilities of some autistic individuals, provides a range of real world examples, and offers some personal insights into his collaborations with Michelle Dawson.
Unraveling the causes of the Ice Age megafauna extinctions
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IMAGE: This is a drawing of a woolly rhino. Credit: Laura Saila
Was it humans or climate change that caused the extinctions of the iconic Ice Age mammals (megafauna) such as the woolly rhinoceros and woolly mammoth?
For decades, scientists have been debating the reasons behind these enigmatic Ice Age mass extinctions, which caused the loss of a third of the large mammal species in Eurasia and two thirds of the species in North America.
Now an extensive, inter-disciplinary research team, involving over 40 academic institutions around the world and led by Professor Eske Willerslev's Centre for GeoGenetics at the Natural History Museum, University of Copenhagen, have tried to tackle the contentious question in the biggest study of its kind. And the answers are far more complicated than ever imagined.
IMAGE: This is a Beringia winter scene.Credit: George Teichmann
The study, just published online in the journal Nature, reveals that neither climate nor humans alone can account for the Ice Age mass extinctions. Using ancient megafauna DNA, climate data and the archaeological record, the findings indicate dramatically different responses of Ice Age species to climate change and humans.
For example, the study shows that humans played no part in the extinction of the woolly rhino or the musk ox in Eurasia and that their demise can be entirely explained by climate change. On the other hand, humans aren't off the hook when it comes to the extinction of the wild horse and the bison in Siberia. Our ancestors share responsibility for the megafauna extinctions with climate change. While the reindeer remain relatively unaffected by any of these factors, the causes of the extinction of the mammoths is still a mystery.
IMAGE: This is a drawing of the Pleistocene landscape.Credit: Mauricio Anton
Eske Willerslev says, "Our findings put a final end to the single-cause theories of the Ice Age extinctions, and suggests that care should be taken in making generalizations not just regarding past and present species extinctions but also those of the future; the impacts of climate change and human encroachment on species extinctions really depends on which species we're looking at."
However, Eline Lorenzen from the University of Copenhagen and lead author of the study says, "We do find that climate change has been intrinsically linked with major megafauna population size changes over the past 50,000 years, supporting the view that populations of many species will decline in the future owing to climate change and habitat loss."
Despite the unparalleled amount of data analysed in this study, the authors find no clear pattern distinguishing species that went extinct from species that survived, suggesting that it will be extremely challenging for experts to predict how existing mammals will respond to future global climate change.
IMAGE: This is a drawing of a woolly rhino. Credit: Laura Saila
Was it humans or climate change that caused the extinctions of the iconic Ice Age mammals (megafauna) such as the woolly rhinoceros and woolly mammoth?
For decades, scientists have been debating the reasons behind these enigmatic Ice Age mass extinctions, which caused the loss of a third of the large mammal species in Eurasia and two thirds of the species in North America.
Now an extensive, inter-disciplinary research team, involving over 40 academic institutions around the world and led by Professor Eske Willerslev's Centre for GeoGenetics at the Natural History Museum, University of Copenhagen, have tried to tackle the contentious question in the biggest study of its kind. And the answers are far more complicated than ever imagined.
IMAGE: This is a Beringia winter scene.Credit: George Teichmann
The study, just published online in the journal Nature, reveals that neither climate nor humans alone can account for the Ice Age mass extinctions. Using ancient megafauna DNA, climate data and the archaeological record, the findings indicate dramatically different responses of Ice Age species to climate change and humans.
For example, the study shows that humans played no part in the extinction of the woolly rhino or the musk ox in Eurasia and that their demise can be entirely explained by climate change. On the other hand, humans aren't off the hook when it comes to the extinction of the wild horse and the bison in Siberia. Our ancestors share responsibility for the megafauna extinctions with climate change. While the reindeer remain relatively unaffected by any of these factors, the causes of the extinction of the mammoths is still a mystery.
IMAGE: This is a drawing of the Pleistocene landscape.Credit: Mauricio Anton
Eske Willerslev says, "Our findings put a final end to the single-cause theories of the Ice Age extinctions, and suggests that care should be taken in making generalizations not just regarding past and present species extinctions but also those of the future; the impacts of climate change and human encroachment on species extinctions really depends on which species we're looking at."
However, Eline Lorenzen from the University of Copenhagen and lead author of the study says, "We do find that climate change has been intrinsically linked with major megafauna population size changes over the past 50,000 years, supporting the view that populations of many species will decline in the future owing to climate change and habitat loss."
Despite the unparalleled amount of data analysed in this study, the authors find no clear pattern distinguishing species that went extinct from species that survived, suggesting that it will be extremely challenging for experts to predict how existing mammals will respond to future global climate change.
Wednesday, November 2, 2011
Jawbone found in England is from the earliest known modern human in northwestern Europe
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A piece of jawbone excavated from a prehistoric cave in England is the earliest evidence for modern humans in Europe, according to an international team of scientists. The bone first was believed to be about 35,000 years old, but the new research study shows it to be significantly older -- between 44,000 and 41,000 years old, according to the findings that will be published in the journal Nature. The new dating of the bone is expected to help scientists pin down how quickly the modern humans spread across Europe during the last Ice Age. It also helps confirm the much-debated theory that early humans coexisted with Neanderthals.
Beth Shapiro, the Shaffer Associate Professor of Biology at Penn State University and a member of the research team, explained that the fragment of maxilla -- the upper jaw -- containing three teeth was unearthed in 1927 in a prehistoric limestone cave called Kent's Cavern in southwestern England. Records from the original excavations, undertaken by the Torquay Natural History Society located in Devon, England, indicate that the jawbone was discovered 10 feet 6 inches beneath the surface and was sealed by stalagmite deposits. "In 1989, scientists at Oxford University dated the bone as being about 35,000 years old. However, doubts were later raised about the reliability of the date because traces of modern glue, which was used to conserve the bone after discovery, were found on the surface," Shapiro said. "We knew we were going to have to do additional testing to re-date the bone." Because the remaining uncontaminated area of bone was deemed too small to re-date, the research team searched through the excavation archives and collections in the Torquay Museum to obtain samples of other animal bones from recorded depths both above and below the spot where the maxilla was found.
Members of the research team then obtained radiocarbon dates for the bones of wolf, deer, cave bear, and woolly rhinoceros, all of which were found close to the maxilla and all which could be dated at between 50,000 and 26,000 years old. Using a Bayesian statistical-modelling method, the scientists then were able to calculate an age for the maxilla. The new date indicates that the bone is between 44,000 and 41,000 years old.
Tom Higham, Deputy Director of Oxford University's Radiocarbon Accelerator Unit and a member of the research team, said "Radiocarbon dating of ancient bones is very difficult to do. Because the initial date from this fragment of jawbone was affected by traces of modern glue, the initial measurement made in 1989 was too young. The new dating evidence we have obtained allows us, for the first time, to pinpoint the real age of this key specimen. We believe this piece of jawbone is the earliest direct evidence we have of modern humans in northwestern Europe."
Shapiro explained that the new and more-accurate date is especially important because it provides clearer evidence about the coexistence of Neanderthals and anatomically modern humans. "If the jawbone is, in fact, 44,000 to 41,000 years old, that means it was from a time when Neanderthals were still present in Europe, so we first had to confirm that the bone was from an anatomically modern human, and not a Neanderthal," Shapiro said. Shapiro and her team first tried to extract mitochondrial DNA from one of the teeth, but there were insufficient amounts for valid DNA sequencing. Eventually, team members were able to use a virtual three-dimensional model based on a CT scan of the jawbone to carry out a detailed analysis of the fossil. They compared the external and internal shapes of the teeth with those of modern human and Neanderthal fossils from a number of different sites. They found early modern human characteristics in all but 3 of the 16 dental characteristics.
Studies of the maxilla have been underway for the last decade, but it was only with the application of the latest investigative and dating techniques that the research team was able to make this breakthrough in identifying the jawbone as the earliest modern human so far known from Europe. "Comparative data were lacking for some of the traits our team was studying," Shapiro said. "So, thankfully, our team member Tim Compton of the Natural History Museum in England helped by building a completely new database to help discriminate modern features from Neanderthal features. While the dominant characteristics are certainly modern, there are some that are ambiguous, or that fall into the Neanderthal range." The research team believe that these ambiguous features may reflect inadequate sampling of modern human variation, shared primitive features between early modern humans and Neanderthals, or even interbreeding between the two species. "We'll have to delve a little deeper and do more work to resolve these questions," Shapiro said.
Another exciting feature of the new study is that it could help solve the apparent discrepancy about the known dates of the Aurignacian period -- a time of cultural development in Europe and southwest Asia that lasted from around 45,000 to 35,000 years ago. Previous researchers have discovered artefacts and tools from this period that are thought to have been produced by the earliest modern humans in Europe. However, strangely, these artifacts have been found to be much older than the rare skeletal remains found in the same vicinity. While Aurignacian tools and ornaments have been dated at as old as 44,000 years, tests to pinpoint the age of relevant human remains have resulted in dates that reach no further than between 41,000 and 39,000 years ago, indicating a significant gap.
"The new date and identification of this bone from Kent's Cavern is very important, as we now have direct evidence that modern humans were in northwest Europe about 42,500 years ago," Higham said. "It confirms the presence of modern humans at the time of the earliest Aurignacian culture, and tells us a great deal about the dispersal speed of our species across Europe during the last Ice Age. It also means that early humans coexisted with Neanderthals in this part of the world, something that a number of researchers have doubted."
A piece of jawbone excavated from a prehistoric cave in England is the earliest evidence for modern humans in Europe, according to an international team of scientists. The bone first was believed to be about 35,000 years old, but the new research study shows it to be significantly older -- between 44,000 and 41,000 years old, according to the findings that will be published in the journal Nature. The new dating of the bone is expected to help scientists pin down how quickly the modern humans spread across Europe during the last Ice Age. It also helps confirm the much-debated theory that early humans coexisted with Neanderthals.
Beth Shapiro, the Shaffer Associate Professor of Biology at Penn State University and a member of the research team, explained that the fragment of maxilla -- the upper jaw -- containing three teeth was unearthed in 1927 in a prehistoric limestone cave called Kent's Cavern in southwestern England. Records from the original excavations, undertaken by the Torquay Natural History Society located in Devon, England, indicate that the jawbone was discovered 10 feet 6 inches beneath the surface and was sealed by stalagmite deposits. "In 1989, scientists at Oxford University dated the bone as being about 35,000 years old. However, doubts were later raised about the reliability of the date because traces of modern glue, which was used to conserve the bone after discovery, were found on the surface," Shapiro said. "We knew we were going to have to do additional testing to re-date the bone." Because the remaining uncontaminated area of bone was deemed too small to re-date, the research team searched through the excavation archives and collections in the Torquay Museum to obtain samples of other animal bones from recorded depths both above and below the spot where the maxilla was found.
Members of the research team then obtained radiocarbon dates for the bones of wolf, deer, cave bear, and woolly rhinoceros, all of which were found close to the maxilla and all which could be dated at between 50,000 and 26,000 years old. Using a Bayesian statistical-modelling method, the scientists then were able to calculate an age for the maxilla. The new date indicates that the bone is between 44,000 and 41,000 years old.
Tom Higham, Deputy Director of Oxford University's Radiocarbon Accelerator Unit and a member of the research team, said "Radiocarbon dating of ancient bones is very difficult to do. Because the initial date from this fragment of jawbone was affected by traces of modern glue, the initial measurement made in 1989 was too young. The new dating evidence we have obtained allows us, for the first time, to pinpoint the real age of this key specimen. We believe this piece of jawbone is the earliest direct evidence we have of modern humans in northwestern Europe."
Shapiro explained that the new and more-accurate date is especially important because it provides clearer evidence about the coexistence of Neanderthals and anatomically modern humans. "If the jawbone is, in fact, 44,000 to 41,000 years old, that means it was from a time when Neanderthals were still present in Europe, so we first had to confirm that the bone was from an anatomically modern human, and not a Neanderthal," Shapiro said. Shapiro and her team first tried to extract mitochondrial DNA from one of the teeth, but there were insufficient amounts for valid DNA sequencing. Eventually, team members were able to use a virtual three-dimensional model based on a CT scan of the jawbone to carry out a detailed analysis of the fossil. They compared the external and internal shapes of the teeth with those of modern human and Neanderthal fossils from a number of different sites. They found early modern human characteristics in all but 3 of the 16 dental characteristics.
Studies of the maxilla have been underway for the last decade, but it was only with the application of the latest investigative and dating techniques that the research team was able to make this breakthrough in identifying the jawbone as the earliest modern human so far known from Europe. "Comparative data were lacking for some of the traits our team was studying," Shapiro said. "So, thankfully, our team member Tim Compton of the Natural History Museum in England helped by building a completely new database to help discriminate modern features from Neanderthal features. While the dominant characteristics are certainly modern, there are some that are ambiguous, or that fall into the Neanderthal range." The research team believe that these ambiguous features may reflect inadequate sampling of modern human variation, shared primitive features between early modern humans and Neanderthals, or even interbreeding between the two species. "We'll have to delve a little deeper and do more work to resolve these questions," Shapiro said.
Another exciting feature of the new study is that it could help solve the apparent discrepancy about the known dates of the Aurignacian period -- a time of cultural development in Europe and southwest Asia that lasted from around 45,000 to 35,000 years ago. Previous researchers have discovered artefacts and tools from this period that are thought to have been produced by the earliest modern humans in Europe. However, strangely, these artifacts have been found to be much older than the rare skeletal remains found in the same vicinity. While Aurignacian tools and ornaments have been dated at as old as 44,000 years, tests to pinpoint the age of relevant human remains have resulted in dates that reach no further than between 41,000 and 39,000 years ago, indicating a significant gap.
"The new date and identification of this bone from Kent's Cavern is very important, as we now have direct evidence that modern humans were in northwest Europe about 42,500 years ago," Higham said. "It confirms the presence of modern humans at the time of the earliest Aurignacian culture, and tells us a great deal about the dispersal speed of our species across Europe during the last Ice Age. It also means that early humans coexisted with Neanderthals in this part of the world, something that a number of researchers have doubted."
New evidence for the earliest modern humans in Europe
Fossil establishes presence of modern humans at both ends of Europe by 40,000 years ago
The timing, process and archeology of the peopling of Europe by early modern humans have been actively debated for more than a century. Reassessment of the anatomy and dating of a fragmentary upper jaw with three teeth from Kent's Cavern in southern England has shed new light on these issues.
Originally found in 1927, Kent's Cavern and its human fossil have been reassessed by an international team, including Erik Trinkaus, PhD, professor of anthropology in Arts & Sciences at Washington University in St. Louis, and the results published in Nature.
The Kent's Cavern human joins the human skull and lower jaw from the Peştera cu Oase, Romania, in establishing the presence of modern humans at both ends of Europe (northwest and southeast) by at least 40,000 years ago.
"Modern humans were previously known to be this old in southeastern Europe, but they had not been documented as early in western Europe until the reassessment of the Kent's Cavern fossil," Trinkaus says. "The new date for the Kent's Cavern upper jaw suggests a rapid spread of modern humans once they had crossed into Europe."
All three of these fossils, although anatomically "modern," possess archaic features, indicating some degree of intermixture with the European Neandertals as modern human spread across Europe.
None of these fossils is associated with diagnostic archeological remains, but they date close to the appearance of the Aurignacian industry, Trinkaus says. This supports the long-held view that the Early Upper Paleolithic Aurignacian represents early modern humans in the region.
Homo sapiens arrived earlier in Europe than previously known
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Members of our species (Homo sapiens) arrived in Europe several millennia earlier than previously thought. At this conclusion a team of researchers, led by the Department of Anthropology, University of Vienna, arrived after re-analyses of two ancient deciduous teeth. These teeth were discovered 1964 in the "Grotta del Cavallo", a prehistoric cave in southern Italy. Since their discovery they have been attributed to Neanderthals, but this new study suggests they belong to anatomically modern humans. Chronometric analysis, carried out by the Oxford Radiocarbon Accelerator Unit at the University of Oxford, shows that the layers within which the teeth were found date to ~43,000-45,000 cal BP. This means that the human remains are older than any other known European modern humans. The research work was published in the renowned science journal Nature.
Grotta del Cavallo, in Apulia, was discovered in 1960. It contained about 7 m of archaeological deposits spanning the period during which Neanderthals were replaced by modern humans. Two milk teeth were unearthed in 1964 by Arturo Palma di Cesnola (emeritus of the University of Siena) from the so-called Uluzzian archaeological layers. The Uluzzian culture has been described from more than 20 separate sites across Italy, and is characterised by personal ornaments, bone tools and colourants; items typically associated with modern human symbolic behaviour. But the teeth from Cavallo were identified in the 1960's as Neanderthals who lived around 200,000 to 40,000 years ago. This attribution has been at the heart of a widely held consensus that the Uluzzian and the complex ornaments and tools within it were also produced by Neanderthals.
Comparison of micro-computed-tomography scans of teeth
Stefano Benazzi, post-doc at the Department of Anthropology at University of Vienna, and his colleagues were able to compare digital models derived from micro-computed tomography scans of the human remains from Grotta del Cavallo with those of a large modern human and Neanderthal dental sample: "We worked with two independent methods: for the one, we measured the thickness of the tooth enamel, and for the other, the general outline of the crown. By means of micro-computed tomography it was possible to compare the internal and external features of the dental crown. The results clearly show that the specimens from Grotta del Cavallo were modern humans, not Neanderthals as originally thought."
New chronometric analyses of the Oxford Radiocarbon Accelerator Unit
Katerina Douka, post-doc at the Research Laboratory for Archaeology and History of Art at the University of Oxford, undertook a comprehensive programme of radiocarbon dating to establish a firm chronology for the finds. Previous dates for the Uluzzian were problematic and affected by contamination. Since the teeth were too small to date directly, Douka developed a new approach that focused on the dating of marine shells found in the same archaeological levels as the teeth. This approach showed that the modern human teeth must date to between ~43,000-45,000 years ago. Douka said, "Radiocarbon dating of Palaeolithic material is difficult because the levels of remaining radiocarbon are very low and contamination can be problematic. Shell beads are important objects of body ornamentation and have allowed us directly and reliably radiocarbon date items associated with these early Homo sapiens settlers of Europe."
IMAGE: Uluzzian artifacts from Grotta del Cavallo, Apulia, southern Italy.
Credit: Annamaria Ronchitelli and Katerina Douka
Uluzzian culture was made by modern humans
"What the new dates mean", Benazzi summarised, "is that these two teeth from Grotta del Cavallo represent the oldest European modern human fossils currently known. This find confirms that the arrival of our species on the continent – and thus the period of coexistence with Neanderthals – was several thousand years longer than previously thought. Based on this fossil evidence, we have confirmed that modern humans and not Neanderthals are the makers of the Uluzzian culture. This has important implications to our understanding of the development of 'fully modern' human behaviour. Whether the colonisation of the continent occurred in one or more waves of expansion and which routes were followed is still to be established."
International collaboration makes it possible
Gerhard Weber, head of the Core Facility for Micro-Computed Tomography and deputy head of the Department of Anthropology at University of Vienna, commented on the discovery in the following way: "Human fossil material is very rare, particularly well preserved deciduous teeth. It is only thanks to the collaboration of several European institutions that fossil remains were accessible. The re-evaluation of the Cavallo material was only made possible through technical innovations developed in the last decade, known as 'Virtual Anthropology'. These new techniques developed for dental morphometrics and also new radiocarbon dating will help to address taxonomic questions associated with other contentious human fossil remains."
Members of our species (Homo sapiens) arrived in Europe several millennia earlier than previously thought. At this conclusion a team of researchers, led by the Department of Anthropology, University of Vienna, arrived after re-analyses of two ancient deciduous teeth. These teeth were discovered 1964 in the "Grotta del Cavallo", a prehistoric cave in southern Italy. Since their discovery they have been attributed to Neanderthals, but this new study suggests they belong to anatomically modern humans. Chronometric analysis, carried out by the Oxford Radiocarbon Accelerator Unit at the University of Oxford, shows that the layers within which the teeth were found date to ~43,000-45,000 cal BP. This means that the human remains are older than any other known European modern humans. The research work was published in the renowned science journal Nature.
Grotta del Cavallo, in Apulia, was discovered in 1960. It contained about 7 m of archaeological deposits spanning the period during which Neanderthals were replaced by modern humans. Two milk teeth were unearthed in 1964 by Arturo Palma di Cesnola (emeritus of the University of Siena) from the so-called Uluzzian archaeological layers. The Uluzzian culture has been described from more than 20 separate sites across Italy, and is characterised by personal ornaments, bone tools and colourants; items typically associated with modern human symbolic behaviour. But the teeth from Cavallo were identified in the 1960's as Neanderthals who lived around 200,000 to 40,000 years ago. This attribution has been at the heart of a widely held consensus that the Uluzzian and the complex ornaments and tools within it were also produced by Neanderthals.
Comparison of micro-computed-tomography scans of teeth
Stefano Benazzi, post-doc at the Department of Anthropology at University of Vienna, and his colleagues were able to compare digital models derived from micro-computed tomography scans of the human remains from Grotta del Cavallo with those of a large modern human and Neanderthal dental sample: "We worked with two independent methods: for the one, we measured the thickness of the tooth enamel, and for the other, the general outline of the crown. By means of micro-computed tomography it was possible to compare the internal and external features of the dental crown. The results clearly show that the specimens from Grotta del Cavallo were modern humans, not Neanderthals as originally thought."
New chronometric analyses of the Oxford Radiocarbon Accelerator Unit
Katerina Douka, post-doc at the Research Laboratory for Archaeology and History of Art at the University of Oxford, undertook a comprehensive programme of radiocarbon dating to establish a firm chronology for the finds. Previous dates for the Uluzzian were problematic and affected by contamination. Since the teeth were too small to date directly, Douka developed a new approach that focused on the dating of marine shells found in the same archaeological levels as the teeth. This approach showed that the modern human teeth must date to between ~43,000-45,000 years ago. Douka said, "Radiocarbon dating of Palaeolithic material is difficult because the levels of remaining radiocarbon are very low and contamination can be problematic. Shell beads are important objects of body ornamentation and have allowed us directly and reliably radiocarbon date items associated with these early Homo sapiens settlers of Europe."
IMAGE: Uluzzian artifacts from Grotta del Cavallo, Apulia, southern Italy.
Credit: Annamaria Ronchitelli and Katerina Douka
Uluzzian culture was made by modern humans
"What the new dates mean", Benazzi summarised, "is that these two teeth from Grotta del Cavallo represent the oldest European modern human fossils currently known. This find confirms that the arrival of our species on the continent – and thus the period of coexistence with Neanderthals – was several thousand years longer than previously thought. Based on this fossil evidence, we have confirmed that modern humans and not Neanderthals are the makers of the Uluzzian culture. This has important implications to our understanding of the development of 'fully modern' human behaviour. Whether the colonisation of the continent occurred in one or more waves of expansion and which routes were followed is still to be established."
International collaboration makes it possible
Gerhard Weber, head of the Core Facility for Micro-Computed Tomography and deputy head of the Department of Anthropology at University of Vienna, commented on the discovery in the following way: "Human fossil material is very rare, particularly well preserved deciduous teeth. It is only thanks to the collaboration of several European institutions that fossil remains were accessible. The re-evaluation of the Cavallo material was only made possible through technical innovations developed in the last decade, known as 'Virtual Anthropology'. These new techniques developed for dental morphometrics and also new radiocarbon dating will help to address taxonomic questions associated with other contentious human fossil remains."
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