German anthropologists have decoded the entire genome sequence of a Denisovan, representative of the extinct Asian group related to Neanderthals, from a finger bone fossil, a study reveals.
The team from The Max Planck Institute for Evolutionary Anthropology, Germany, has now developed sensitive novel techniques which have allowed them to sequence every position in the Denisovan genome about 30 times over, using DNA extracted from less than 10 milligrams of the finger bone.
This level of resolution was sufficient to establish the relationship of Denisovans to Neanderthals and present-day humans, but often made it impossible for researchers to study the evolution of specific parts of the genome.
The now-completed version of the genome allows even the small differences between the copies of genes, that this individual inherited from its mother and father to be distinguished, a university statement said.
The finger bone was discovered by Anatoly Derevianko and Michail Shunkov, professors at the Russian Academy of Sciences in 2008 during their excavations at Denisova Cave, in southern Siberia.
In 2010, Svante Pääbo and colleagues from Max Planck presented a draft version of the genome from the finger bone fragment.
The Leipzig group will make the entire Denisovan genome sequence available for the scientific community over the internet Feb 8.
"The genome is of very high quality", said Matthias Meyer, who developed the technique.
"We cover all non-repetitive DNA sequences in the Denisovan genome so many times that it has fewer errors than most genomes from present-day humans that have been determined to date," said Meyer.
The genome represents the first high-coverage, complete genome sequence of an archaic human group -- a leap in the study of extinct forms of humans.
"We hope that biologists will be able to use this genome to discover genetic changes that were important for the development of modern human culture and technology, and enabled modern humans to leave Africa and rapidly spread around the world, starting around 100,000 years ago," said Svante Pääbo.
The project is being financed by the Max Planck Society and is part of efforts since almost 30 years by Pääbo's group to study ancient DNA.
http://www.phenomenica.com/2012/02/entire-genome-of-denisovan-decoded-from.html
Showing posts with label anthropology. Show all posts
Showing posts with label anthropology. Show all posts
Sunday, February 12, 2012
Tuesday, December 13, 2011
Savanna Chimps Exhibit Human-Like Sharing Behavior, Anthropologists Say
ScienceDaily (Dec. 1, 2011) — Sharing food has widely been considered by scholars as a defining characteristic of human behavior. But a new study by Iowa State University anthropology professor Jill Pruetz now reports that chimpanzees from her Fongoli research site in Senegal also frequently share food and hunting tools with other chimps.
Co-authored by ISU anthropology graduate student Stacy Lindshield, their study is posted online in Primates and will be published in a future issue of the journal.
The researchers witnessed 41 cases of Fongoli chimpanzees willingly transferring either wild plant foods or hunting tools to other chimpanzees. While previous research by primatologists had documented chimps transferring meat among other non-relatives, this is the first study to document non-meat sharing behavior.
"They're [the Fongoli chimps] not the only chimps that share, but in terms of the resources that we cover here, that is unique," said Pruetz (left), who was named a 2008 National Geographic Emerging Explorer for her research on savanna chimpanzees in Senegal. "I guess all chimps share meat, but they don't share plants or tools. Yet they do here, in addition to meat. It was intriguing when we first started seeing these events."
Read more here ...
Co-authored by ISU anthropology graduate student Stacy Lindshield, their study is posted online in Primates and will be published in a future issue of the journal.
The researchers witnessed 41 cases of Fongoli chimpanzees willingly transferring either wild plant foods or hunting tools to other chimpanzees. While previous research by primatologists had documented chimps transferring meat among other non-relatives, this is the first study to document non-meat sharing behavior.
"They're [the Fongoli chimps] not the only chimps that share, but in terms of the resources that we cover here, that is unique," said Pruetz (left), who was named a 2008 National Geographic Emerging Explorer for her research on savanna chimpanzees in Senegal. "I guess all chimps share meat, but they don't share plants or tools. Yet they do here, in addition to meat. It was intriguing when we first started seeing these events."
Read more here ...
Tuesday, November 8, 2011
Monkey Moms Are Key To Sons’ Reproductive Success
If you are a male human, nothing puts a damper on romantic success like having your mother in tow. If you are a male northern muriqui monkey, however, mom’s presence may be your best bet to find and successfully mate with just the right girl at the right time.
In a study of wild primates, reported this week (Nov. 7, 2011) in the Proceedings of the National Academy of Sciences, University of Wisconsin-Madison anthropologist Karen B. Strier describes a monkey society where equality and tolerance rule and where sexually mature males, still living at home, seem to get helpful access to mates by the mere presence of their mothers and other maternal kin.
The new study, which combines Strier’s long-term behavioral studies of wild muriquis with new genetic assays obtained from their scat, is important because it can inform conservation practices for critically endangered primates. But the study’s big surprise, says Strier, was evidence that could extend the ‘grandmother hypothesis,’ the notion that human females evolved to live well past their reproductive years because of the rearing advantages conferred by post-menopausal women on their grandchildren.
The northern muriqui is a large, long-lived, socially complex and critically endangered New World primate. There are at most 1,000 animals left in patches of the Brazilian Atlantic Forest , the only place the species is found.
The monkey has been the subject of intensive behavioral study by Strier and her Brazilian colleagues for nearly three decades. Muriqui culture stands in stark contrast to many other primate societies: It is egalitarian, peaceful, and reproductive success, it seems, is spread evenly across the males of a group instead of determined by male social rank, as it is in most other species.
Read more ...
In a study of wild primates, reported this week (Nov. 7, 2011) in the Proceedings of the National Academy of Sciences, University of Wisconsin-Madison anthropologist Karen B. Strier describes a monkey society where equality and tolerance rule and where sexually mature males, still living at home, seem to get helpful access to mates by the mere presence of their mothers and other maternal kin.
The new study, which combines Strier’s long-term behavioral studies of wild muriquis with new genetic assays obtained from their scat, is important because it can inform conservation practices for critically endangered primates. But the study’s big surprise, says Strier, was evidence that could extend the ‘grandmother hypothesis,’ the notion that human females evolved to live well past their reproductive years because of the rearing advantages conferred by post-menopausal women on their grandchildren.
The northern muriqui is a large, long-lived, socially complex and critically endangered New World primate. There are at most 1,000 animals left in patches of the Brazilian Atlantic Forest , the only place the species is found.
The monkey has been the subject of intensive behavioral study by Strier and her Brazilian colleagues for nearly three decades. Muriqui culture stands in stark contrast to many other primate societies: It is egalitarian, peaceful, and reproductive success, it seems, is spread evenly across the males of a group instead of determined by male social rank, as it is in most other species.
Read more ...
Thursday, November 3, 2011
Friday, July 29, 2011
People at darker, higher latitudes evolved bigger eyes and brains
"As you move away from the equator, there's less and less light available, so humans have had to evolve bigger and bigger eyes," said Eiluned Pearce from the Institute of Cognitive and Evolutionary Anthropology at Oxford University, a lead author on the study.
"Their brains also need to be bigger to deal with the extra visual input. Having bigger brains doesn't mean that higher-latitude humans are smarter, it just means they need bigger brains to be able to see well where they live."
This suggests that someone from Greenland and someone from Kenya will have the same ability to discern detail, but the person from the higher latitude needs more brainpower and bigger eyes to deal with the lower light levels.
Professor Robin Dunbar, director of the Institute of Cognitive and Evolutionary Anthropology at Oxford University and a co-author of the study, said that people whose ancestors have lived within the Arctic circle, have eyeballs 20% bigger than people whose ancestors lived near the equator. They have an associated increase in the size of the brain's visual cortex, which previous studies have shown correlates with the size of the eyeball.
Brain volume is known to increase with latitude: people living at high latitudes north and south of the equator have bigger brains than people living near the equator and . Dunbar said that scientists have wondered whether these inherited differences in total brain volume were driven by the pressure to adapt to low light levels at high latitudes.
The researchers measured the brain volumes and eye sockets of 55 skulls kept at the Oxford University Museum of Natural History dating from the 19th century. The skulls represented 12 different populations from around the world, including indigenous people from England, Australia, China, Kenya, Micronesia and Scandinavia.
The results, published on Wednesday in the journal Biology Letters, showed that the biggest brains, averaging 1,484 millilitres, were from Scandinavia, while the smallest brains, around 1,200 millilitres, came from Micronesia. Average eye socket size was 27 millilitres in Scandinavia and 22 millilitres in Micronesia.
Dunbar said the increase in brain volume must have evolved relatively recently in human history. "It's only within the last 10,000 years or so that modern humans have occupied all latitudes right up to the Arctic circle. This is, I guess, an adaptation that's happened within the last 10,000 years."
The researchers controlled for possible confounding variables influencing their data, such as the fact that people who live at higher latitudes are physically bigger and the possibility that the size of a person's eye socket in colder climates might be bigger to allow for a thicker layer of insulating fat.
The results for human eyes mirror those found in birds and non-human primates. Bird species that sing earlier in the dawn chorus at high latitudes have bigger eyes than those that sing later, and nocturnal primates have bigger eyeballs than species that are awake during the day.
guardian.co.uk
Thursday, July 28, 2011
World's oldest ritual discovered
A startling archaeological discovery that may have gone un-noticed changes our understanding of human history. While, up until now, scholars have largely held that man's first rituals were carried out over 40,000 years ago in Europe, it now appears that they were wrong about both the time and place.
Associate Professor Sheila Coulson, from the University of Oslo, has shown that modern humans, Homo sapiens, have performed advanced rituals in Africa for 70,000 years. She has, in other words, discovered mankind's oldest known ritual.
The archaeologist made the surprising discovery several years ago while she was studying the origin of the San people. A group of the San live in the sparsely inhabited area of north-western Botswana known as Ngamiland.
Coulson made the discovery while searching for artifacts from the Middle Stone Age in the only hills present for hundreds of kilometers in any direction. This group of small peaks within the Kalahari Desert is known as the Tsodilo Hills and is famous for having the largest concentration of rock paintings in the world.
The Tsodilo Hills are still a sacred place for the San, who call them the Mountains of the Gods and the Rock that Whispers. The python is one of the San's most important animals. According to their creation myth, mankind descended from the python and the ancient, arid streambeds around the hills are said to have been created by the python as it circled the hills in its ceaseless search for water.
Sheila Coulson's find shows that people from the area had a specific ritual location associated with the python. The ritual was held in a little cave on the northern side of the Tsodilo Hills. The cave itself is so secluded and access to it is so difficult that it was not even discovered by archaeologists until the 1990s.
When Coulson entered the cave in the summer of 2007 with her three master's students, it struck them that the mysterious rock resembled the head of a huge python. On the six-meter long by two-meter tall rock, they found three-to-four hundred indentations that could only have been man-made.
"You could see the mouth and eyes of the snake. It looked like a real python. The play of sunlight over the indentations gave them the appearance of snake skin. At night, the firelight gave one the feeling that the snake was actually moving".
They found no evidence that work had recently been done on the rock. In fact, much of the rock's surface was extensively eroded. When they saw the many indentations in the rock, the archaeologists wondered about more than when the work had been done. They also began thinking about what the cave had been used for and how long people had been going there. With these questions in mind, they decided to dig a test pit directly in front of the python stone.
At the bottom of the pit, they found many stones that had been used to make the indentations. Together with these tools, some of which were more than 70,000 years old, they found a piece of the wall that had fallen off during the work.
In the course of their excavation, they found more than 13,000 artifacts. All of the objects were spearheads and articles that could be connected with ritual use, as well as tools used in carving the stone. They found nothing else.
As if that were not enough, the stones that the spearheads were made from are not from the Tsodilo region but must have been brought from hundreds of kilometers away.
The spearheads are better crafted and more colorful than other spearheads from the same time and area. Surprisingly enough, it was only the red spearheads that had been burned.
"Stone age people took these colorful spearheads, brought them to the cave, and finished carving them there. Only the red spearheads were burned. It was a ritual destruction of artifacts. There was no sign of normal habitation. No ordinary tools were found at the site. Our find means that humans were more organized and had the capacity for abstract thinking at a much earlier point in history than we have previously assumed. All of the indications suggest that Tsodilo has been known to mankind for almost 100,000 years as a very special place in the pre-historic landscape." says Sheila Coulson.
Sheila Coulson also noticed a secret chamber behind the python stone. Some areas of the entrance to this small chamber were worn smooth, indicating that many people had passed through it over the years.
"The shaman, who is still a very important person in San culture, could have kept himself hidden in that secret chamber. He would have had a good view of the inside of the cave while remaining hidden himself. When he spoke from his hiding place, it could have seemed as if the voice came from the snake itself. The shaman would have been able to control everything. It was perfect."
The shaman could also have disappeared from the chamber by crawling out onto the hillside through a small shaft. While large cave and wall paintings are numerous throughout the Tsodilo Hills, there are only two small paintings in this cave: an elephant and a giraffe. These images were rendered, surprisingly, exactly where water runs down the wall.
Sheila Coulson thinks that an explanation for this might come from San mythology.
In one San story, the python falls into a body of water and cannot get out by itself. The python is pulled from the water by a giraffe. The elephant, with its long trunk, is often used as a metaphor for the python.
"In the cave, we find only the San people's three most important animals: the python, the elephant, and the giraffe. That is unusual. This would appear to be a very special place. They did not burn the spearheads by chance. They brought them from hundreds of kilometers away and intentionally burned them. So many pieces of the puzzle fit together here. It has to represent a ritual." concludes Sheila Coulson.
It was a major archaeological find years ago that made it possible for Sheila Coulson to date the finds in this little cave in Botswana. Up until the turn of the century, archaeologists believed that human civilization developed in Europe after our ancestors migrated from Africa. This theory was crushed by Archaeologist Christopher Henshilwood when he published his find of traces from a Middle Stone Age dwelling in the Blombos Cave in Southern Cape, South Africa.
Author: Lori Henshey
Source: Examiner [July 11, 2011]
http://archaeologynewsnetwork.blogspot.com/2011/07/worlds-oldest-ritual-discovered.html?utm_source=feedburner&utm_medium=email&utm_campaign=Feed:+TheArchaeologyNewsNetwork+(The+Archaeology+News+Network)
Associate Professor Sheila Coulson, from the University of Oslo, has shown that modern humans, Homo sapiens, have performed advanced rituals in Africa for 70,000 years. She has, in other words, discovered mankind's oldest known ritual.
The archaeologist made the surprising discovery several years ago while she was studying the origin of the San people. A group of the San live in the sparsely inhabited area of north-western Botswana known as Ngamiland.
Coulson made the discovery while searching for artifacts from the Middle Stone Age in the only hills present for hundreds of kilometers in any direction. This group of small peaks within the Kalahari Desert is known as the Tsodilo Hills and is famous for having the largest concentration of rock paintings in the world.
The Tsodilo Hills are still a sacred place for the San, who call them the Mountains of the Gods and the Rock that Whispers. The python is one of the San's most important animals. According to their creation myth, mankind descended from the python and the ancient, arid streambeds around the hills are said to have been created by the python as it circled the hills in its ceaseless search for water.
Sheila Coulson's find shows that people from the area had a specific ritual location associated with the python. The ritual was held in a little cave on the northern side of the Tsodilo Hills. The cave itself is so secluded and access to it is so difficult that it was not even discovered by archaeologists until the 1990s.
When Coulson entered the cave in the summer of 2007 with her three master's students, it struck them that the mysterious rock resembled the head of a huge python. On the six-meter long by two-meter tall rock, they found three-to-four hundred indentations that could only have been man-made.
"You could see the mouth and eyes of the snake. It looked like a real python. The play of sunlight over the indentations gave them the appearance of snake skin. At night, the firelight gave one the feeling that the snake was actually moving".
They found no evidence that work had recently been done on the rock. In fact, much of the rock's surface was extensively eroded. When they saw the many indentations in the rock, the archaeologists wondered about more than when the work had been done. They also began thinking about what the cave had been used for and how long people had been going there. With these questions in mind, they decided to dig a test pit directly in front of the python stone.
At the bottom of the pit, they found many stones that had been used to make the indentations. Together with these tools, some of which were more than 70,000 years old, they found a piece of the wall that had fallen off during the work.
In the course of their excavation, they found more than 13,000 artifacts. All of the objects were spearheads and articles that could be connected with ritual use, as well as tools used in carving the stone. They found nothing else.
As if that were not enough, the stones that the spearheads were made from are not from the Tsodilo region but must have been brought from hundreds of kilometers away.
The spearheads are better crafted and more colorful than other spearheads from the same time and area. Surprisingly enough, it was only the red spearheads that had been burned.
"Stone age people took these colorful spearheads, brought them to the cave, and finished carving them there. Only the red spearheads were burned. It was a ritual destruction of artifacts. There was no sign of normal habitation. No ordinary tools were found at the site. Our find means that humans were more organized and had the capacity for abstract thinking at a much earlier point in history than we have previously assumed. All of the indications suggest that Tsodilo has been known to mankind for almost 100,000 years as a very special place in the pre-historic landscape." says Sheila Coulson.
Sheila Coulson also noticed a secret chamber behind the python stone. Some areas of the entrance to this small chamber were worn smooth, indicating that many people had passed through it over the years.
"The shaman, who is still a very important person in San culture, could have kept himself hidden in that secret chamber. He would have had a good view of the inside of the cave while remaining hidden himself. When he spoke from his hiding place, it could have seemed as if the voice came from the snake itself. The shaman would have been able to control everything. It was perfect."
The shaman could also have disappeared from the chamber by crawling out onto the hillside through a small shaft. While large cave and wall paintings are numerous throughout the Tsodilo Hills, there are only two small paintings in this cave: an elephant and a giraffe. These images were rendered, surprisingly, exactly where water runs down the wall.
Sheila Coulson thinks that an explanation for this might come from San mythology.
In one San story, the python falls into a body of water and cannot get out by itself. The python is pulled from the water by a giraffe. The elephant, with its long trunk, is often used as a metaphor for the python.
"In the cave, we find only the San people's three most important animals: the python, the elephant, and the giraffe. That is unusual. This would appear to be a very special place. They did not burn the spearheads by chance. They brought them from hundreds of kilometers away and intentionally burned them. So many pieces of the puzzle fit together here. It has to represent a ritual." concludes Sheila Coulson.
It was a major archaeological find years ago that made it possible for Sheila Coulson to date the finds in this little cave in Botswana. Up until the turn of the century, archaeologists believed that human civilization developed in Europe after our ancestors migrated from Africa. This theory was crushed by Archaeologist Christopher Henshilwood when he published his find of traces from a Middle Stone Age dwelling in the Blombos Cave in Southern Cape, South Africa.
Author: Lori Henshey
Source: Examiner [July 11, 2011]
http://archaeologynewsnetwork.blogspot.com/2011/07/worlds-oldest-ritual-discovered.html?utm_source=feedburner&utm_medium=email&utm_campaign=Feed:+TheArchaeologyNewsNetwork+(The+Archaeology+News+Network)
Tuesday, July 26, 2011
Study to create the first archive of human evolution at Mungo
A foundational project is currently underway at Lake Mungo and those lakes that abound it to document the history of human settlement, past environmental change and landscape evolution that has occurred in this area. This immense undertaking comes after a long hiatus of research being conducted here and hopes to provide the first systematic archive of its archaeological traces.
Documenting the history of human settlement seems like an epic task in any part of the world; in the stark beauty of the Willandra Lakes World Heritage Area, it involves tracing back no less than 45,000 years.
Upon arriving to the now dry lake bed which lies at the heart of Mungo National Park, it is not hard to appreciate the ancient nature of this part of the world - it is one of the oldest places outside of Africa to have been occupied by modern humans.
The site of the world's oldest known cremation and ritual ochre burial, as well as the longest trail of ancient human footprints, surprisingly little is known about the people who lived here.
Enter La Trobe University's palaeolithic archaeologist, Dr Nicola Stern, whose Mungo Archaeology Project hopes to redress this shortfall in our collective knowledge.
"There's an untold story at Mungo; Mungo is famous because of Mungo Lady, Mungo Man; a trail of fossil footprints," says Dr Stern.
"We know surprisingly little about how people actually lived in this landscape over 45,000 years - and that's really what I'm trying to document by looking at the archaeological traces in the Mungo lunette."
The Mungo lunettes are half-moon shaped sand dunes built from ancient layers of the earth's surface and form the 'Walls of China' - a major drawcard for visitors to the World Heritage site that is Mungo National Park.
Containing rich deposits of information, the lunettes have preserved hundreds of rare, snapshot images of Australia's earliest history and provide a unique record of the ways in which the first settlers may have adapted to the changes to their climate over time.
They form the basis for Dr Stern's foundational research into this narrative of human evolution.
"It's the foundation - there's a lot that we could do if we had already had this information," she says.
It is not only the scientific community who have longed for this work to be done; elders from the region's Aboriginal tribal groups are also supportive of the project and are working in collaboration with Dr Stern's team to monitor it.
"Finding out what's there, and then monitoring what's happening to what's there, is something that the elders tell me they have wanted for a very long period of time."
With such an endeavour, Dr Stern has a loyal team of around 20 others working with her and says there will be more to come on board in the future.
"Over time we will be training people and hope that they will pick this up and carry it on into the future - but there is a certain, you know knowledge and expertise that is required to figure out how to tackle a record on this scale."
Author: Charlotte King
Source: ABC News Website [July 14, 2011]
http://archaeologynewsnetwork.blogspot.com/2011/07/study-to-create-first-archive-of-human.html
Documenting the history of human settlement seems like an epic task in any part of the world; in the stark beauty of the Willandra Lakes World Heritage Area, it involves tracing back no less than 45,000 years.
Upon arriving to the now dry lake bed which lies at the heart of Mungo National Park, it is not hard to appreciate the ancient nature of this part of the world - it is one of the oldest places outside of Africa to have been occupied by modern humans.
The site of the world's oldest known cremation and ritual ochre burial, as well as the longest trail of ancient human footprints, surprisingly little is known about the people who lived here.
Enter La Trobe University's palaeolithic archaeologist, Dr Nicola Stern, whose Mungo Archaeology Project hopes to redress this shortfall in our collective knowledge.
"There's an untold story at Mungo; Mungo is famous because of Mungo Lady, Mungo Man; a trail of fossil footprints," says Dr Stern.
"We know surprisingly little about how people actually lived in this landscape over 45,000 years - and that's really what I'm trying to document by looking at the archaeological traces in the Mungo lunette."
The Mungo lunettes are half-moon shaped sand dunes built from ancient layers of the earth's surface and form the 'Walls of China' - a major drawcard for visitors to the World Heritage site that is Mungo National Park.
Containing rich deposits of information, the lunettes have preserved hundreds of rare, snapshot images of Australia's earliest history and provide a unique record of the ways in which the first settlers may have adapted to the changes to their climate over time.
They form the basis for Dr Stern's foundational research into this narrative of human evolution.
"It's the foundation - there's a lot that we could do if we had already had this information," she says.
It is not only the scientific community who have longed for this work to be done; elders from the region's Aboriginal tribal groups are also supportive of the project and are working in collaboration with Dr Stern's team to monitor it.
"Finding out what's there, and then monitoring what's happening to what's there, is something that the elders tell me they have wanted for a very long period of time."
With such an endeavour, Dr Stern has a loyal team of around 20 others working with her and says there will be more to come on board in the future.
"Over time we will be training people and hope that they will pick this up and carry it on into the future - but there is a certain, you know knowledge and expertise that is required to figure out how to tackle a record on this scale."
Author: Charlotte King
Source: ABC News Website [July 14, 2011]
http://archaeologynewsnetwork.blogspot.com/2011/07/study-to-create-first-archive-of-human.html
Friday, June 10, 2011
The Anthropocene - A man-made world
 |
| You maniacs! You blew it up! |
May 26th 2011
THE here and now are defined by astronomy and geology. Astronomy takes care of the here: a planet orbiting a yellow star embedded in one of the spiral arms of the Milky Way, a galaxy that is itself part of the Virgo supercluster, one of millions of similarly vast entities dotted through the sky. Geology deals with the now: the 10,000-year-old Holocene epoch, a peculiarly stable and clement part of the Quaternary period, a time distinguished by regular shifts into and out of ice ages. The Quaternary forms part of the 65m-year Cenozoic era, distinguished by the opening of the North Atlantic, the rise of the Himalayas, and the widespread presence of mammals and flowering plants. This era in turn marks the most recent part of the Phanerozoic aeon, the 540m-year chunk of the Earth’s history wherein rocks with fossils of complex organisms can be found. The regularity of celestial clockwork and the solid probity of rock give these co-ordinates a reassuring constancy.
Now there is a movement afoot to change humanity’s co-ordinates. In 2000 Paul Crutzen, an eminent atmospheric chemist, realised he no longer believed he was living in the Holocene. He was living in some other age, one shaped primarily by people. From their trawlers scraping the floors of the seas to their dams impounding sediment by the gigatonne, from their stripping of forests to their irrigation of farms, from their mile-deep mines to their melting of glaciers, humans were bringing about an age of planetary change. With a colleague, Eugene Stoermer, Dr Crutzen suggested this age be called the Anthropocene—“the recent age of man”.
The term has slowly picked up steam, both within the sciences (the International Commission on Stratigraphy, ultimate adjudicator of the geological time scale, is taking a formal interest) and beyond. This May statements on the environment by concerned Nobel laureates and the Pontifical Academy of Sciences both made prominent use of the term, capitalising on the way in which it dramatises the sheer scale of human activity.
The advent of the Anthropocene promises more, though, than a scientific nicety or a new way of grabbing the eco-jaded public’s attention. The term “paradigm shift” is bandied around with promiscuous ease. But for the natural sciences to make human activity central to its conception of the world, rather than a distraction, would mark such a shift for real. For centuries, science has progressed by making people peripheral. In the 16th century Nicolaus Copernicus moved the Earth from its privileged position at the centre of the universe. In the 18th James Hutton opened up depths of geological time that dwarf the narrow now. In the 19th Charles Darwin fitted humans onto a single twig of the evolving tree of life. As Simon Lewis, an ecologist at the University of Leeds, points out, embracing the Anthropocene as an idea means reversing this trend. It means treating humans not as insignificant observers of the natural world but as central to its workings, elemental in their force.
Sous la plage, les pavés
The most common way of distinguishing periods of geological time is by means of the fossils they contain. On this basis picking out the Anthropocene in the rocks of days to come will be pretty easy. Cities will make particularly distinctive fossils. A city on a fast-sinking river delta (and fast-sinking deltas, undermined by the pumping of groundwater and starved of sediment by dams upstream, are common Anthropocene environments) could spend millions of years buried and still, when eventually uncovered, reveal through its crushed structures and weird mixtures of materials that it is unlike anything else in the geological record.
The fossils of living creatures will be distinctive, too. Geologists define periods through assemblages of fossil life reliably found together. One of the characteristic markers of the Anthropocene will be the widespread remains of organisms that humans use, or that have adapted to life in a human-dominated world. According to studies by Erle Ellis, an ecologist at the University of Maryland, Baltimore County, the vast majority of ecosystems on the planet now reflect the presence of people. There are, for instance, more trees on farms than in wild forests. And these anthropogenic biomes are spread about the planet in a way that the ecological arrangements of the prehuman world were not. The fossil record of the Anthropocene will thus show a planetary ecosystem homogenised through domestication.
More sinisterly, there are the fossils that will not be found. Although it is not yet inevitable, scientists warn that if current trends of habitat loss continue, exacerbated by the effects of climate change, there could be an imminent and dramatic number of extinctions before long.
All these things would show future geologists that humans had been present. But though they might be diagnostic of the time in which humans lived, they would not necessarily show that those humans shaped their time in the way that people pushing the idea of the Anthropocene want to argue. The strong claim of those announcing the recent dawning of the age of man is that humans are not just spreading over the planet, but are changing the way it works.
Such workings are the province of Earth-system science, which sees the planet not just as a set of places, or as the subject of a history, but also as a system of forces, flows and feedbacks that act upon each other. This system can behave in distinctive and counterintuitive ways, including sometimes flipping suddenly from one state to another. To an Earth-system scientist the difference between the Quaternary period (which includes the Holocene) and the Neogene, which came before it, is not just what was living where, or what the sea level was; it is that in the Neogene the climate stayed stable whereas in the Quaternary it swung in and out of a series of ice ages. The Earth worked differently in the two periods.
The clearest evidence for the system working differently in the Anthropocene comes from the recycling systems on which life depends for various crucial elements. In the past couple of centuries people have released quantities of fossil carbon that the planet took hundreds of millions of years to store away. This has given them a commanding role in the planet’s carbon cycle.
Although the natural fluxes of carbon dioxide into and out of the atmosphere are still more than ten times larger than the amount that humans put in every year by burning fossil fuels, the human addition matters disproportionately because it unbalances those natural flows. As Mr Micawber wisely pointed out, a small change in income can, in the absence of a compensating change in outlays, have a disastrous effect. The result of putting more carbon into the atmosphere than can be taken out of it is a warmer climate, a melting Arctic, higher sea levels, improvements in the photosynthetic efficiency of many plants, an intensification of the hydrologic cycle of evaporation and precipitation, and new ocean chemistry.
All of these have knock-on effects both on people and on the processes of the planet. More rain means more weathering of mountains. More efficient photosynthesis means less evaporation from croplands. And the changes in ocean chemistry are the sort of thing that can be expected to have a direct effect on the geological record if carbon levels rise far enough.
At a recent meeting of the Geological Society of London that was devoted to thinking about the Anthropocene and its geological record, Toby Tyrrell of the University of Southampton pointed out that pale carbonate sediments—limestones, chalks and the like—cannot be laid down below what is called a “carbonate compensation depth”. And changes in chemistry brought about by the fossil-fuel carbon now accumulating in the ocean will raise the carbonate compensation depth, rather as a warmer atmosphere raises the snowline on mountains. Some ocean floors which are shallow enough for carbonates to precipitate out as sediment in current conditions will be out of the game when the compensation depth has risen, like ski resorts too low on a warming alp. New carbonates will no longer be laid down. Old ones will dissolve. This change in patterns of deep-ocean sedimentation will result in a curious, dark band of carbonate-free rock—rather like that which is seen in sediments from the Palaeocene-Eocene thermal maximum, an episode of severe greenhouse warming brought on by the release of pent-up carbon 56m years ago.
The fix is in
No Dickensian insights are necessary to appreciate the scale of human intervention in the nitrogen cycle. One crucial part of this cycle—the fixing of pure nitrogen from the atmosphere into useful nitrogen-containing chemicals—depends more or less entirely on living things (lightning helps a bit). And the living things doing most of that work are now people (see chart). By adding industrial clout to the efforts of the microbes that used to do the job single-handed, humans have increased the annual amount of nitrogen fixed on land by more than 150%. Some of this is accidental. Burning fossil fuels tends to oxidise nitrogen at the same time. The majority is done on purpose, mostly to make fertilisers. This has a variety of unwholesome consequences, most importantly the increasing number of coastal “dead zones” caused by algal blooms feeding on fertiliser-rich run-off waters.
Industrial nitrogen’s greatest environmental impact, though, is to increase the number of people. Although nitrogen fixation is not just a gift of life—it has been estimated that 100m people were killed by explosives made with industrially fixed nitrogen in the 20th century’s wars—its net effect has been to allow a huge growth in population. About 40% of the nitrogen in the protein that humans eat today got into that food by way of artificial fertiliser. There would be nowhere near as many people doing all sorts of other things to the planet if humans had not sped the nitrogen cycle up.
It is also worth noting that unlike many of humanity’s other effects on the planet, the remaking of the nitrogen cycle was deliberate. In the late 19th century scientists diagnosed a shortage of nitrogen as a planet-wide problem. Knowing that natural processes would not improve the supply, they invented an artificial one, the Haber process, that could make up the difference. It was, says Mark Sutton of the Centre for Ecology and Hydrology in Edinburgh, the first serious human attempt at geoengineering the planet to bring about a desired goal. The scale of its success outstripped the imaginings of its instigators. So did the scale of its unintended consequences.
For many of those promoting the idea of the Anthropocene, further geoengineering may now be in order, this time on the carbon front. Left to themselves, carbon-dioxide levels in the atmosphere are expected to remain high for 1,000 years—more, if emissions continue to go up through this century. It is increasingly common to hear climate scientists arguing that this means things should not be left to themselves—that the goal of the 21st century should be not just to stop the amount of carbon in the atmosphere increasing, but to start actively decreasing it. This might be done in part by growing forests (see article) and enriching soils, but it might also need more high-tech interventions, such as burning newly grown plant matter in power stations and pumping the resulting carbon dioxide into aquifers below the surface, or scrubbing the air with newly contrived chemical-engineering plants, or intervening in ocean chemistry in ways that would increase the sea’s appetite for the air’s carbon.
To think of deliberately interfering in the Earth system will undoubtedly be alarming to some. But so will an Anthropocene deprived of such deliberation. A way to try and split the difference has been propounded by a group of Earth-system scientists inspired by (and including) Dr Crutzen under the banner of “planetary boundaries”. The planetary-boundaries group, which published a sort of manifesto in 2009, argues for increased restraint and, where necessary, direct intervention aimed at bringing all sorts of things in the Earth system, from the alkalinity of the oceans to the rate of phosphate run-off from the land, close to the conditions pertaining in the Holocene. Carbon-dioxide levels, the researchers recommend, should be brought back from whatever they peak at to a level a little higher than the Holocene’s and a little lower than today’s.
The idea behind this precautionary approach is not simply that things were good the way they were. It is that the further the Earth system gets from the stable conditions of the Holocene, the more likely it is to slip into a whole new state and change itself yet further.
The Earth’s history shows that the planet can indeed tip from one state to another, amplifying the sometimes modest changes which trigger the transition. The nightmare would be a flip to some permanently altered state much further from the Holocene than things are today: a hotter world with much less productive oceans, for example. Such things cannot be ruled out. On the other hand, the invocation of poorly defined tipping points is a well worn rhetorical trick for stirring the fears of people unperturbed by current, relatively modest, changes.
In general, the goal of staying at or returning close to Holocene conditions seems judicious. It remains to be seen if it is practical. The Holocene never supported a civilisation of 10 billion reasonably rich people, as the Anthropocene must seek to do, and there is no proof that such a population can fit into a planetary pot so circumscribed. So it may be that a “good Anthropocene”, stable and productive for humans and other species they rely on, is one in which some aspects of the Earth system’s behaviour are lastingly changed. For example, the Holocene would, without human intervention, have eventually come to an end in a new ice age. Keeping the Anthropocene free of ice ages will probably strike most people as a good idea.
Dreams of a smart planet
That is an extreme example, though. No new ice age is due for some millennia to come. Nevertheless, to see the Anthropocene as a blip that can be minimised, and from which the planet, and its people, can simply revert to the status quo, may be to underestimate the sheer scale of what is going on.
Take energy. At the moment the amount of energy people use is part of what makes the Anthropocene problematic, because of the carbon dioxide given off. That problem will not be solved soon enough to avert significant climate change unless the Earth system is a lot less prone to climate change than most scientists think. But that does not mean it will not be solved at all. And some of the zero-carbon energy systems that solve it—continent- scale electric grids distributing solar energy collected in deserts, perhaps, or advanced nuclear power of some sort—could, in time, be scaled up to provide much more energy than today’s power systems do. As much as 100 clean terawatts, compared to today’s dirty 15TW, is not inconceivable for the 22nd century. That would mean humanity was producing roughly as much useful energy as all the world’s photosynthesis combined.
In a fascinating recent book, “Revolutions that Made the Earth”, Timothy Lenton and Andrew Watson, Earth-system scientists at the universities of Exeter and East Anglia respectively, argue that large changes in the amount of energy available to the biosphere have, in the past, always marked large transitions in the way the world works. They have a particular interest in the jumps in the level of atmospheric oxygen seen about 2.4 billion years ago and 600m years ago. Because oxygen is a particularly good way of getting energy out of organic matter (if it weren’t, there would be no point in breathing) these shifts increased sharply the amount of energy available to the Earth’s living things. That may well be why both of those jumps seem to be associated with subsequent evolutionary leaps—the advent of complex cells, in the first place, and of large animals, in the second. Though the details of those links are hazy, there is no doubt that in their aftermath the rules by which the Earth system operated had changed.
The growing availability of solar or nuclear energy over the coming centuries could mark the greatest new energy resource since the second of those planetary oxidations, 600m years ago—a change in the same class as the greatest the Earth system has ever seen. Dr Lenton (who is also one of the creators of the planetary-boundaries concept) and Dr Watson suggest that energy might be used to change the hydrologic cycle with massive desalination equipment, or to speed up the carbon cycle by drawing down atmospheric carbon dioxide, or to drive new recycling systems devoted to tin and copper and the many other metals as vital to industrial life as carbon and nitrogen are to living tissue. Better to embrace the Anthropocene’s potential as a revolution in the way the Earth system works, they argue, than to try to retreat onto a low-impact path that runs the risk of global immiseration.
Such a choice is possible because of the most fundamental change in Earth history that the Anthropocene marks: the emergence of a form of intelligence that allows new ways of being to be imagined and, through co-operation and innovation, to be achieved. The lessons of science, from Copernicus to Darwin, encourage people to dismiss such special pleading. So do all manner of cultural warnings, from the hubris around which Greek tragedies are built to the lamentation of King David’s preacher: “Vanity of vanities, all is vanity…the Earth abideth for ever…and there is no new thing under the sun.” But the lamentation of vanity can be false modesty. On a planetary scale, intelligence is something genuinely new and powerful. Through the domestication of plants and animals intelligence has remade the living environment. Through industry it has disrupted the key biogeochemical cycles. For good or ill, it will do yet more.
It may seem nonsense to think of the (probably sceptical) intelligence with which you interpret these words as something on a par with plate tectonics or photosynthesis. But dam by dam, mine by mine, farm by farm and city by city it is remaking the Earth before your eyes.
http://www.economist.com/node/18741749
Tuesday, May 3, 2011
For many Russians, UFO and Bigfoot equally realistic
26.04.2011
A paradox was revealed during a recent poll of the Russians. In spite of the fact that approximately 70 percent of the country's population call themselves believers, only 26 percent believe that life after death is possible. The beliefs of the Russians are generally contradictory: Russians bring Easter cakes to church to "make them holy" but at the same time are afraid of black cats and broken mirrors.
"Public opinion" fund decided to poll the Russians on the possibility of resurrection after death. The fund found out that despite the fact that 59 percent of the citizens consider themselves Orthodox, and ten percent say that they belong to other denominations, only 26 percent believe in an afterlife.
For 54 percent resurrection is no more than a myth. The majority of those who do not believe in the afterlife are represented by rural residents, men, students and seniors.
Another interesting fact is those who do believe in the afterlife are people with an income of over 30,000 rubles a month, entrepreneurs and executives. Surprisingly, there were more of those who believed in eternal life among the businessmen than among those who call themselves Orthodox Christians: 43 percent versus 31.
According to the numerous surveys and studies, human faith is generally a collection of paradoxes and even absurdities. Russians who call themselves Orthodox Christians consider it their duty to wear a cross, but at the same time do not shy away from horoscopes and psychics' services. A growing number of advertisement promising "to return the beloved one" and "ward off a competitor" indicate a growing demand.
Generally in the recent years Russians have become much more skeptical. Horoscopes, prophetic dreams and professional astrologers are still popular among the population, but to a much lesser extent. Alien life for the majority of the Russians is as much a fairy tale as the life after death. Possibility of the existence of extraterrestrial civilizations is denied by 58 percent of Russians.
However, the skepticism of the Russian people does not apply to every day superstitions. Little green creatures and life after death seem to be a myth to many, while troubles promised by a meeting with a black cat, a broken mirror or spilt salt are quite real for the most. The Russians believe that spitting over the left shoulder and knocking on wood is much more effective than a prayer or a call to the spirits.
It is worth mentioning that the representatives of the Church are not surprised by such data. Priests say that identifying themselves as Orthodox, people are not talking about religion, but, rather, the national and family tradition and culture. This means that many Russians do not believe in God, but call themselves Orthodox.
In fact, for many Russians a visit to a church during holidays or baptizing children is the same thing as knocking on wood or avoiding "jinxing," i.e., and old tradition designed to ward off trouble.
However, Russians are not the only ones that have such a strange attitude to religion. For example, 43 percent of Americans attend religious ceremonies every week, but this does not prevent 38 percent of the U.S. adults from believing in the existence of aliens, 33 percent believing in Bigfoot, and 37 percent - in ghosts. Of these, 23 percent are convinced that ghosts are their dead relatives or friends, while 20 percent said they personally met with the spirits of the dead.
Experts, however, argue that there is no paradox here. "Traditional" (in moderation) religion does not interfere with the belief in the paranormal, but quite the contrary: being open to the faith into the unknown, people are not so steadfast in their religious beliefs that reject the mysterious events in principle.
In other words, people who admit the existence of things unexplained from the viewpoint of science can be (or call themselves) Christians (Muslims, Jews), and with the same sincerity believe that aliens have visited Earth a number of times. An individual open to the faith in a higher intelligence, in principle can believe in some seemingly conflicting things. Traditional religions are traditional because people transfer their commitment to a particular confession from generation to generation, observing certain rituals as a family. But it is often nothing more than a tribute to the national culture, rather than a sincere belief and commitment to a wholly-owned church dogma.
Ksenia Obraztsova
Pravda.Ru
http://english.pravda.ru/society/stories/26-04-2011/117700-russians_ufo_bigfoot-0/
A paradox was revealed during a recent poll of the Russians. In spite of the fact that approximately 70 percent of the country's population call themselves believers, only 26 percent believe that life after death is possible. The beliefs of the Russians are generally contradictory: Russians bring Easter cakes to church to "make them holy" but at the same time are afraid of black cats and broken mirrors.
"Public opinion" fund decided to poll the Russians on the possibility of resurrection after death. The fund found out that despite the fact that 59 percent of the citizens consider themselves Orthodox, and ten percent say that they belong to other denominations, only 26 percent believe in an afterlife.
For 54 percent resurrection is no more than a myth. The majority of those who do not believe in the afterlife are represented by rural residents, men, students and seniors.
Another interesting fact is those who do believe in the afterlife are people with an income of over 30,000 rubles a month, entrepreneurs and executives. Surprisingly, there were more of those who believed in eternal life among the businessmen than among those who call themselves Orthodox Christians: 43 percent versus 31.
According to the numerous surveys and studies, human faith is generally a collection of paradoxes and even absurdities. Russians who call themselves Orthodox Christians consider it their duty to wear a cross, but at the same time do not shy away from horoscopes and psychics' services. A growing number of advertisement promising "to return the beloved one" and "ward off a competitor" indicate a growing demand.
Generally in the recent years Russians have become much more skeptical. Horoscopes, prophetic dreams and professional astrologers are still popular among the population, but to a much lesser extent. Alien life for the majority of the Russians is as much a fairy tale as the life after death. Possibility of the existence of extraterrestrial civilizations is denied by 58 percent of Russians.
However, the skepticism of the Russian people does not apply to every day superstitions. Little green creatures and life after death seem to be a myth to many, while troubles promised by a meeting with a black cat, a broken mirror or spilt salt are quite real for the most. The Russians believe that spitting over the left shoulder and knocking on wood is much more effective than a prayer or a call to the spirits.
It is worth mentioning that the representatives of the Church are not surprised by such data. Priests say that identifying themselves as Orthodox, people are not talking about religion, but, rather, the national and family tradition and culture. This means that many Russians do not believe in God, but call themselves Orthodox.
In fact, for many Russians a visit to a church during holidays or baptizing children is the same thing as knocking on wood or avoiding "jinxing," i.e., and old tradition designed to ward off trouble.
However, Russians are not the only ones that have such a strange attitude to religion. For example, 43 percent of Americans attend religious ceremonies every week, but this does not prevent 38 percent of the U.S. adults from believing in the existence of aliens, 33 percent believing in Bigfoot, and 37 percent - in ghosts. Of these, 23 percent are convinced that ghosts are their dead relatives or friends, while 20 percent said they personally met with the spirits of the dead.
Experts, however, argue that there is no paradox here. "Traditional" (in moderation) religion does not interfere with the belief in the paranormal, but quite the contrary: being open to the faith into the unknown, people are not so steadfast in their religious beliefs that reject the mysterious events in principle.
In other words, people who admit the existence of things unexplained from the viewpoint of science can be (or call themselves) Christians (Muslims, Jews), and with the same sincerity believe that aliens have visited Earth a number of times. An individual open to the faith in a higher intelligence, in principle can believe in some seemingly conflicting things. Traditional religions are traditional because people transfer their commitment to a particular confession from generation to generation, observing certain rituals as a family. But it is often nothing more than a tribute to the national culture, rather than a sincere belief and commitment to a wholly-owned church dogma.
Ksenia Obraztsova
Pravda.Ru
http://english.pravda.ru/society/stories/26-04-2011/117700-russians_ufo_bigfoot-0/
Friday, March 25, 2011
First humans in Americas: prehistoric Texans?
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/
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/
Monday, March 14, 2011
How man 'lost his penile spines'
9 March 2011
By Neil Bowdler
Science reporter, BBC News
Scientists believe men once had small spines on their genitalia such as those found in chimpanzees, cats and mice.
Analysis of the genomes of humans, chimpanzees and macaques indicates that a DNA sequence thought to play a role in the production of these spines have been deleted in humans, but has been preserved in other primates.
It suggests another genetic deletion may have led to the expansion of specific regions of the human brain.
The study is in the journal Nature.
The researchers at Stanford, Georgia and Pennsylvania State universities in the US wanted to trace evolutionary changes in human DNA.
They compared the human genome with those of the chimpanzee and macaque, and came up with 510 stretches of DNA that have been conserved in our primate relatives but deleted in humans.
Nearly all these DNA regions appear to play a regulatory role in the function of nearby genes.
The researchers then focused on two deletions, linking one to penile spines and another to the growth of specific areas of the brain.
They then tested the effects of the deleted sequences in human skin and neural tissue, and found further evidence to support their claims.
"We're trying to find the molecular basis of being human," said Professor David Kingsley of Stanford University, one of the authors of the study.
"That's a really ambitious goal; but we live at this unique time where we have the complete genome sequence of ourselves and our closest relatives, so you can systematically go through and find all the ways that we differ from other organisms."
Arms race
Penile spines are barb-like structures found in many mammals. Their role remains under debate, and they may play different roles in different species.
They may increase stimulation for the male during mating. They might also play a part in inducing female ovulation in a small number of species, but there is evidence that they can cause damage to the female too.
Then there is the suggestion that they might have evolved to remove "mating plugs" - material that some male species deposit in the female genital tract to block other males' attempts to fertilise the same female.
"It's been proposed these structures can help remove the copulatory plugs left by other males; so in some mammals with multi-male mating systems, there's quite a little arms race going on for fertilisation," said Professor Kingsley.
The researchers believe the loss of these spines in humans may be related to changes in human courtship.
The loss of spines, they say, would result in less sensitivity and longer copulation, and may be associated with stronger pair-bonding in humans and greater paternal care for human offspring.
http://www.bbc.co.uk/news/science-environment-12689692
By Neil Bowdler
Science reporter, BBC News
Scientists believe men once had small spines on their genitalia such as those found in chimpanzees, cats and mice.
Analysis of the genomes of humans, chimpanzees and macaques indicates that a DNA sequence thought to play a role in the production of these spines have been deleted in humans, but has been preserved in other primates.
It suggests another genetic deletion may have led to the expansion of specific regions of the human brain.
The study is in the journal Nature.
The researchers at Stanford, Georgia and Pennsylvania State universities in the US wanted to trace evolutionary changes in human DNA.
They compared the human genome with those of the chimpanzee and macaque, and came up with 510 stretches of DNA that have been conserved in our primate relatives but deleted in humans.
Nearly all these DNA regions appear to play a regulatory role in the function of nearby genes.
The researchers then focused on two deletions, linking one to penile spines and another to the growth of specific areas of the brain.
They then tested the effects of the deleted sequences in human skin and neural tissue, and found further evidence to support their claims.
"We're trying to find the molecular basis of being human," said Professor David Kingsley of Stanford University, one of the authors of the study.
"That's a really ambitious goal; but we live at this unique time where we have the complete genome sequence of ourselves and our closest relatives, so you can systematically go through and find all the ways that we differ from other organisms."
Arms race
Penile spines are barb-like structures found in many mammals. Their role remains under debate, and they may play different roles in different species.
They may increase stimulation for the male during mating. They might also play a part in inducing female ovulation in a small number of species, but there is evidence that they can cause damage to the female too.
Then there is the suggestion that they might have evolved to remove "mating plugs" - material that some male species deposit in the female genital tract to block other males' attempts to fertilise the same female.
"It's been proposed these structures can help remove the copulatory plugs left by other males; so in some mammals with multi-male mating systems, there's quite a little arms race going on for fertilisation," said Professor Kingsley.
The researchers believe the loss of these spines in humans may be related to changes in human courtship.
The loss of spines, they say, would result in less sensitivity and longer copulation, and may be associated with stronger pair-bonding in humans and greater paternal care for human offspring.
http://www.bbc.co.uk/news/science-environment-12689692
Sunday, February 20, 2011
Man's First Best Friend Might Have Been A Fox
by NPR StaffFebruary 19, 2011
In a dusty, ancient burial site in northern Jordan, archaeologists have made a startling discovery: a fox buried alongside human remains.
It seems some 16,000 years ago, several millennia before any animals were domesticated, humans may have been making an early attempt to keep pets. Red foxes, to be precise.
It's a surprising find, Cambridge researcher Lisa Maher tells NPR's Linda Wertheimer. "When we were first excavating the site, we thought it might have been a dog," she says. It wasn't until her team analyzed the animal's remains that it realized it was a fox.
That the fox was a pet is only one of several possibilities, however. It may instead have had totemic or spiritual significance to the culture. But Maher's team compared the burial site to sites from 4,000 years later, when domesticated dogs did accompany human burials. The similarities suggest "that it probably was a more emotional relationship of one particular fox to one particular person," she says.
Those similarities are also significant because they highlight a continuity in mortuary practices through time, Maher adds. "We're seeing these things, these similarities in mortuary practices and relationships to humans and animals in a much greater time depth than we had previously."
If the fox were indeed a pet, it would be a pretty big deal. "It's certainly a big deal for prehistoric archeology," Maher says, "but it's also a big deal for how we understand human-animal relationships today and in the past."
http://www.npr.org/2011/02/19/133898499/mans-first-best-friend-might-have-been-a-fox
Tuesday, February 15, 2011
The moment Britain became an island
15 February 2011
By Megan Lane
BBC News Magazine
Ancient Britain was a peninsula until a tsunami flooded its land-links to Europe some 8,000 years ago. Did that wave help shape the national character?
The coastline and landscape of what would become modern Britain began to emerge at the end of the last Ice Age around 10,000 years ago.
What had been a cold, dry tundra on the north-western edge of Europe grew warmer and wetter as the ice caps melted. The Irish Sea, North Sea and the Channel were all dry land, albeit land slowly being submerged as sea levels rose.
But it wasn't until 6,100BC that Britain broke free of mainland Europe for good, during the Mesolithic period - the Middle Stone Age.
It is thought that landslides in Norway - the Storegga Slides - triggered one of the biggest tsunamis ever recorded on Earth when a landlocked sea in the Norwegian trench burst its banks.
The water struck the north-east of Britain with such force it travelled 25 miles (40km) inland, turning low-lying plains into what is now the North Sea, and marshlands to the south into the Channel. Britain became an island nation.
At the time it was home to a fragile and scattered population of about 5,000 hunter-gatherers, descended from the early humans who had followed migrating herds of mammoth and reindeer onto the jagged peninsula.
"The waves would have been maybe as much as 10m (33ft) high," says geologist David Smith, of Oxford University. "Anyone standing out on the mud flats at that time would have been dismembered. The speed [of the water] was just so great."
At Montrose, on the north-east coast of Scotland, Smith has uncovered signs of this long-ago natural disaster. A layer of ancient sand runs through what should be banks of continuous clay - sand washed inland by the inundation.
Relics of these pre-island times are being recovered from under the sea off the Isle of Wight, dating from when the Solent was dry land.
Grooved timbers preserved by the saltwater are thought to be the remains of 8,000-year-old log boats, and point to the site once being a sizable boat-building yard, says Garry Momber, of the Hampshire and Wight Trust for Maritime Archaeology (see video clip below).
The tsunami was a watershed in our history, says archaeologist Neil Oliver, presenter of BBC Two's A History of Ancient Britain.
"The people living in the land that would become Britain had become different. They'd been made different. And at the same time, they'd been made a wee bit special as well."
Being so closely bordered by water meant boat-building and seafaring became a way of life. Many millennia on from the tsunami, the British sailed the ocean waves to find new lands and build an empire.
Its more recent history bristles with naval heroes, sea battles and famous explorers. English, Scottish, Welsh and Irish migrants left their homelands to settle far and wide. And Elizabeth I was not only a notable monarch for being a woman, but for presiding over a famous naval victory, and English forays into New World exploration.
But the idea of England - in particular - being a maritime nation has its roots as much in spin as in reality, says Dr Nigel Rigby, of the National Maritime Museum. An early exponent was the 16th Century writer Richard Hakluyt, who promoted the settlement of North America.
Hakluyt's writings played on the growing desire to seek new territories after the loss of Calais in 1558.
"Hakluyt's Voyages spun the idea that the English had always been stirrers and searchers abroad. But it was not really an island that had started to see a future at sea."
By the time Charles I took the throne, the lure of maritime power had taken hold. "He called his great warship the Sovereign of the Seas. It was a statement of intent," says Rigby.
For hundreds of years, ships, goods and people moved to and from the British Isles. Merchant and naval ships alike were staffed by those from far and wide, some of whom settled in its ports.
But just as Britain could reach out to the world from its safe harbours, so, too, could the world reach in - and this fuelled feelings of vulnerability, says Rigby. If an invader can make it across one's watery defences, the British coastline offers an abundance of places in which to make landfall.
"The 19th Century writer Alfred Thayer Mahan made the point that if you look at the coastline of Britain, it's suited to maritime trade with good harbours. But easy access for trade means it's also vulnerable to attack from the sea.
"In times of national threat, this is a recurring fear. Hence the importance of being able to defeat enemies at sea," says Rigby.
Mahan's writings underlined the sense of Britain as an island nation, defined by its relationship with the sea. This identity was further bolstered by the likes of the novelist Erskine Childers, who wrote The Riddle of the Sands, a spy novel in the early 20th Century about a German plot to invade from across the North Sea.
"The idea of an 'island nation' is something of a cultural construct," says Rigby.
"But in Britain you are never more than 60 miles from the sea. So it's important to be able to defend the coastline, and to be able to make a living from all around that coastline too."
In the past, historian David Starkey has argued that Henry VIII's break from the Catholic Church in Rome made him the first Eurosceptic.
"In plans for the elaborate coastal defences that Henry commissioned we can see how England no longer defined itself as part of Europe, but as separate from it - a nation apart," he wrote in the Camden New Journal.
"Catholic Europe was now the threat, the launch pad for invasion. In other words Henry was the first Eurosceptic: the xenophobic, insular politics he created have helped to define English history for the past five centuries."
Find out about ancient sites, and activities relating to ancient Britain, on the BBC Hands On History website.
http://www.bbc.co.uk/news/magazine-12244964
(Submitted by Dawn Holloway)
By Megan Lane
BBC News Magazine
Ancient Britain was a peninsula until a tsunami flooded its land-links to Europe some 8,000 years ago. Did that wave help shape the national character?
The coastline and landscape of what would become modern Britain began to emerge at the end of the last Ice Age around 10,000 years ago.
What had been a cold, dry tundra on the north-western edge of Europe grew warmer and wetter as the ice caps melted. The Irish Sea, North Sea and the Channel were all dry land, albeit land slowly being submerged as sea levels rose.
But it wasn't until 6,100BC that Britain broke free of mainland Europe for good, during the Mesolithic period - the Middle Stone Age.
It is thought that landslides in Norway - the Storegga Slides - triggered one of the biggest tsunamis ever recorded on Earth when a landlocked sea in the Norwegian trench burst its banks.
The water struck the north-east of Britain with such force it travelled 25 miles (40km) inland, turning low-lying plains into what is now the North Sea, and marshlands to the south into the Channel. Britain became an island nation.
At the time it was home to a fragile and scattered population of about 5,000 hunter-gatherers, descended from the early humans who had followed migrating herds of mammoth and reindeer onto the jagged peninsula.
"The waves would have been maybe as much as 10m (33ft) high," says geologist David Smith, of Oxford University. "Anyone standing out on the mud flats at that time would have been dismembered. The speed [of the water] was just so great."
At Montrose, on the north-east coast of Scotland, Smith has uncovered signs of this long-ago natural disaster. A layer of ancient sand runs through what should be banks of continuous clay - sand washed inland by the inundation.
Relics of these pre-island times are being recovered from under the sea off the Isle of Wight, dating from when the Solent was dry land.
Grooved timbers preserved by the saltwater are thought to be the remains of 8,000-year-old log boats, and point to the site once being a sizable boat-building yard, says Garry Momber, of the Hampshire and Wight Trust for Maritime Archaeology (see video clip below).
The tsunami was a watershed in our history, says archaeologist Neil Oliver, presenter of BBC Two's A History of Ancient Britain.
"The people living in the land that would become Britain had become different. They'd been made different. And at the same time, they'd been made a wee bit special as well."
Being so closely bordered by water meant boat-building and seafaring became a way of life. Many millennia on from the tsunami, the British sailed the ocean waves to find new lands and build an empire.
Its more recent history bristles with naval heroes, sea battles and famous explorers. English, Scottish, Welsh and Irish migrants left their homelands to settle far and wide. And Elizabeth I was not only a notable monarch for being a woman, but for presiding over a famous naval victory, and English forays into New World exploration.
But the idea of England - in particular - being a maritime nation has its roots as much in spin as in reality, says Dr Nigel Rigby, of the National Maritime Museum. An early exponent was the 16th Century writer Richard Hakluyt, who promoted the settlement of North America.
Hakluyt's writings played on the growing desire to seek new territories after the loss of Calais in 1558.
"Hakluyt's Voyages spun the idea that the English had always been stirrers and searchers abroad. But it was not really an island that had started to see a future at sea."
By the time Charles I took the throne, the lure of maritime power had taken hold. "He called his great warship the Sovereign of the Seas. It was a statement of intent," says Rigby.
For hundreds of years, ships, goods and people moved to and from the British Isles. Merchant and naval ships alike were staffed by those from far and wide, some of whom settled in its ports.
But just as Britain could reach out to the world from its safe harbours, so, too, could the world reach in - and this fuelled feelings of vulnerability, says Rigby. If an invader can make it across one's watery defences, the British coastline offers an abundance of places in which to make landfall.
"The 19th Century writer Alfred Thayer Mahan made the point that if you look at the coastline of Britain, it's suited to maritime trade with good harbours. But easy access for trade means it's also vulnerable to attack from the sea.
"In times of national threat, this is a recurring fear. Hence the importance of being able to defeat enemies at sea," says Rigby.
Mahan's writings underlined the sense of Britain as an island nation, defined by its relationship with the sea. This identity was further bolstered by the likes of the novelist Erskine Childers, who wrote The Riddle of the Sands, a spy novel in the early 20th Century about a German plot to invade from across the North Sea.
"The idea of an 'island nation' is something of a cultural construct," says Rigby.
"But in Britain you are never more than 60 miles from the sea. So it's important to be able to defend the coastline, and to be able to make a living from all around that coastline too."
Many believe its island status has also shaped Britain's rather detached attitude to Europe today, which is still often referred to as "the continent".
"In plans for the elaborate coastal defences that Henry commissioned we can see how England no longer defined itself as part of Europe, but as separate from it - a nation apart," he wrote in the Camden New Journal.
"Catholic Europe was now the threat, the launch pad for invasion. In other words Henry was the first Eurosceptic: the xenophobic, insular politics he created have helped to define English history for the past five centuries."
Find out about ancient sites, and activities relating to ancient Britain, on the BBC Hands On History website.
http://www.bbc.co.uk/news/magazine-12244964
(Submitted by Dawn Holloway)
Thursday, February 10, 2011
On their own 2 feet: 3.2 million-year-old fossil foot bone supports humanlike bipedalism in Lucy's species
February 10, 2011
A fossilized foot bone recovered from Hadar, Ethiopia, shows that by 3.2 million years ago human ancestors walked bipedally with a modern human-like foot, a report that appears Feb. 11 in the journal Science, concludes. The fossil, a fourth metatarsal, or midfoot bone, indicates that a permanently arched foot was present in the species Australopithecus afarensis, according to the report authors, Carol Ward of the University of Missouri, together with William Kimbel and Donald Johanson, of Arizona State University's Institute of Human Origins.
The research helps resolve a long-standing debate between paleoanthropologists who think A. afarensis walked essentially as modern humans do and those who think this species practiced a form of locomotion intermediate between the quadrupedal tree-climbing of chimpanzees and human terrestrial bipedalism. The question of whether A. afarensis had fully developed pedal, or foot, arches has been part of this debate. The fourth metatarsal described in the Science report provides strong evidence for the arches and, the authors argue, support a modern-human style of locomotion for this species. The specimen was recovered from the Hadar locality 333, popularly known as the "First Family Site," the richest source of A. afarensis fossils in eastern Africa, with more than 250 specimens, representing at least 17 individuals, so far known.
"This fourth metatarsal is the only one known of A. afarensis and is a key piece of evidence for the early evolution of the uniquely human way of walking," says Kimbel. "The ongoing work at Hadar is producing rare parts of the skeleton that are absolutely critical for understanding how our species evolved."
Humans, uniquely among primates, have two arches in their feet, longitudinal and transverse, which are composed of the midfoot bones and supported by muscles in the sole of the foot. During bipedal locomotion, these arches perform two critical functions: leverage when the foot pushes off the ground and shock absorption when the sole of the foot meets the ground at the completion of the stride. Ape feet lack permanent arches, are more flexible than human feet and have a highly mobile large toe, important attributes for climbing and grasping in the trees. None of these apelike features are present in the foot of A. afarensis.
"Understanding that the foot arches appeared very early in our evolution shows that the unique structure of our feet is fundamental to human locomotion," observes Ward. "If we can understand what we were designed to do and how natural selection shaped the human skeleton, we can gain insight into how our skeletons work today. Arches in our feet were just as important for our ancestors as they are for us."
This species, whose best-known specimen is "Lucy," lived in eastern Africa 3.0.8 million years ago. Prior to A. afarensis, the species A. anamensis was present in Kenya and Ethiopia from 4.2 to 4.0 million years ago, but its skeleton is not well known. At 4.4 million years ago, Ethiopia's Ardipithecus ramidus is the earliest human ancestor well represented by skeletal remains. Although Ardipithecus appears to have been a part-time terrestrial biped, its foot retains many features of tree-dwelling primates, including a divergent, mobile first toe. The foot of A. afarensis, as with other parts of its skeleton, is much more like that of living humans, implying that by the time of Lucy, our ancestors no longer depended on the trees for refuge or resources.
The Hadar project is the longest running paleoanthropology field program in the Ethiopian rift valley, now spanning more than 38 years. Since 1973, the fieldwork at Hadar has produced more than 370 fossil specimens of Australopithecus afarensis between 3.4 and 3.0 million years ago – one of the largest collections of a single fossil hominin species in Africa – as well as one of the earliest known fossils of Homo and abundant Oldowan stone tools (ca. 2.3 million).
Through ASU's Institute of Human Origins, the Hadar project plays an important role in training Ethiopian scholars by offering graduate degree and postdoctoral opportunities in the U.S. Promotion of local awareness of the global scientific importance and Ethiopian cultural heritage value of the Hadar site is also a project priority. Additionally, the fundraising phase of a planned "Hadar Interpretive Center" at Eloaha town, 30 kilometers from the site, was successfully completed in January 2011.
Provided by Arizona State University (news : web)
http://www.physorg.com/news/2011-02-feet-million-year-old-fossil-foot-bone.html
A fossilized foot bone recovered from Hadar, Ethiopia, shows that by 3.2 million years ago human ancestors walked bipedally with a modern human-like foot, a report that appears Feb. 11 in the journal Science, concludes. The fossil, a fourth metatarsal, or midfoot bone, indicates that a permanently arched foot was present in the species Australopithecus afarensis, according to the report authors, Carol Ward of the University of Missouri, together with William Kimbel and Donald Johanson, of Arizona State University's Institute of Human Origins.
The research helps resolve a long-standing debate between paleoanthropologists who think A. afarensis walked essentially as modern humans do and those who think this species practiced a form of locomotion intermediate between the quadrupedal tree-climbing of chimpanzees and human terrestrial bipedalism. The question of whether A. afarensis had fully developed pedal, or foot, arches has been part of this debate. The fourth metatarsal described in the Science report provides strong evidence for the arches and, the authors argue, support a modern-human style of locomotion for this species. The specimen was recovered from the Hadar locality 333, popularly known as the "First Family Site," the richest source of A. afarensis fossils in eastern Africa, with more than 250 specimens, representing at least 17 individuals, so far known.
"This fourth metatarsal is the only one known of A. afarensis and is a key piece of evidence for the early evolution of the uniquely human way of walking," says Kimbel. "The ongoing work at Hadar is producing rare parts of the skeleton that are absolutely critical for understanding how our species evolved."
Humans, uniquely among primates, have two arches in their feet, longitudinal and transverse, which are composed of the midfoot bones and supported by muscles in the sole of the foot. During bipedal locomotion, these arches perform two critical functions: leverage when the foot pushes off the ground and shock absorption when the sole of the foot meets the ground at the completion of the stride. Ape feet lack permanent arches, are more flexible than human feet and have a highly mobile large toe, important attributes for climbing and grasping in the trees. None of these apelike features are present in the foot of A. afarensis.
"Understanding that the foot arches appeared very early in our evolution shows that the unique structure of our feet is fundamental to human locomotion," observes Ward. "If we can understand what we were designed to do and how natural selection shaped the human skeleton, we can gain insight into how our skeletons work today. Arches in our feet were just as important for our ancestors as they are for us."
This species, whose best-known specimen is "Lucy," lived in eastern Africa 3.0.8 million years ago. Prior to A. afarensis, the species A. anamensis was present in Kenya and Ethiopia from 4.2 to 4.0 million years ago, but its skeleton is not well known. At 4.4 million years ago, Ethiopia's Ardipithecus ramidus is the earliest human ancestor well represented by skeletal remains. Although Ardipithecus appears to have been a part-time terrestrial biped, its foot retains many features of tree-dwelling primates, including a divergent, mobile first toe. The foot of A. afarensis, as with other parts of its skeleton, is much more like that of living humans, implying that by the time of Lucy, our ancestors no longer depended on the trees for refuge or resources.
The Hadar project is the longest running paleoanthropology field program in the Ethiopian rift valley, now spanning more than 38 years. Since 1973, the fieldwork at Hadar has produced more than 370 fossil specimens of Australopithecus afarensis between 3.4 and 3.0 million years ago – one of the largest collections of a single fossil hominin species in Africa – as well as one of the earliest known fossils of Homo and abundant Oldowan stone tools (ca. 2.3 million).
Through ASU's Institute of Human Origins, the Hadar project plays an important role in training Ethiopian scholars by offering graduate degree and postdoctoral opportunities in the U.S. Promotion of local awareness of the global scientific importance and Ethiopian cultural heritage value of the Hadar site is also a project priority. Additionally, the fundraising phase of a planned "Hadar Interpretive Center" at Eloaha town, 30 kilometers from the site, was successfully completed in January 2011.
Provided by Arizona State University (news : web)
http://www.physorg.com/news/2011-02-feet-million-year-old-fossil-foot-bone.html
Tuesday, February 1, 2011
Finding Would Reveal Contact between Humans and Gomphotheres in North America
Tuesday, February 1, 2011
MEXICO CITY.- Mexican Archaeologists discovered 3 Clovis projectile heads associated to remains of gomphotheres with an age of at least 12,000 years, in the northern region of the Mexican state of Sonora. The finding is relevant because these are the first evidences in North America of this extinct animal linked to the human species.
The finding opens the possibility of the coexistence of humankind with gomphotheres, animals similar to mammoths, but smaller, in this region of America, which contrasts with theories that declare that this species disappeared 30,000 years ago in this region of America and did not coexist with humans.
The discovery took place in early January 2011 in El Fin del Mundo, Sonora by researchers from the National Institute of Anthropology and History (INAH), during the third field season at the site identified as a hunting and quartering area during the Pleistocene.
This finding completes a scene in which archaeologists visualized how Clovis groups hunted this elephant ancestor. “This is an unprecedented finding in Mexico since it is the first time that projectile heads are found associated to a bone bed of this kind of proboscides.
“There is no other Clovis archaeological site where gomphotheres have been found, not even in the United States, where most important Clovis Culture findings have been registered, and these vestiges are dated between 10,600 and 11,600 years” informed archaeologist Guadalupe Sanchez, director of the Fin del Mundo Research Project.
“The discovery took place in the same archaeological context where in 2008 gomphothere bones and different lithic tools were found on the surface, among them, a quartz crystal Clovis head”.
Clovis people are also known as hunters of mammoths, one of 3 proboscide species that lived in America, being the other 2 the mastodon and the gomphothere. The last was the smallest and the earliest to appear in the Americas.
Gomphotheres have only been found associated to humans in South America, and the southernmost Clovis heads were found in Costa Rica; human evidence associated with proboscides was limited mastodons and mammoths, until now.
The INAH archaeologist Natalia Martinez, head of the field research, explained that Clovis projectile heads were discovered in the point named Localidad 1, the remainder of a swamp with deposits of the Pleistocene and Holocene eras, and were freed by scraping carefully a hard soil block.
The lithic artifacts manufactured by Clovis people to hunt great animals, were located a few centimeters under the gomphothere discovered in previous field seasons part of the research project conducted by the INAH, the University of Arizona and the National Geographic Society.
http://www.artdaily.org/index.asp?int_sec=2&int_new=44345
(Submitted by Terry W. Colvin)
MEXICO CITY.- Mexican Archaeologists discovered 3 Clovis projectile heads associated to remains of gomphotheres with an age of at least 12,000 years, in the northern region of the Mexican state of Sonora. The finding is relevant because these are the first evidences in North America of this extinct animal linked to the human species.
The finding opens the possibility of the coexistence of humankind with gomphotheres, animals similar to mammoths, but smaller, in this region of America, which contrasts with theories that declare that this species disappeared 30,000 years ago in this region of America and did not coexist with humans.
The discovery took place in early January 2011 in El Fin del Mundo, Sonora by researchers from the National Institute of Anthropology and History (INAH), during the third field season at the site identified as a hunting and quartering area during the Pleistocene.
This finding completes a scene in which archaeologists visualized how Clovis groups hunted this elephant ancestor. “This is an unprecedented finding in Mexico since it is the first time that projectile heads are found associated to a bone bed of this kind of proboscides.
“There is no other Clovis archaeological site where gomphotheres have been found, not even in the United States, where most important Clovis Culture findings have been registered, and these vestiges are dated between 10,600 and 11,600 years” informed archaeologist Guadalupe Sanchez, director of the Fin del Mundo Research Project.
“The discovery took place in the same archaeological context where in 2008 gomphothere bones and different lithic tools were found on the surface, among them, a quartz crystal Clovis head”.
Clovis people are also known as hunters of mammoths, one of 3 proboscide species that lived in America, being the other 2 the mastodon and the gomphothere. The last was the smallest and the earliest to appear in the Americas.
Gomphotheres have only been found associated to humans in South America, and the southernmost Clovis heads were found in Costa Rica; human evidence associated with proboscides was limited mastodons and mammoths, until now.
The INAH archaeologist Natalia Martinez, head of the field research, explained that Clovis projectile heads were discovered in the point named Localidad 1, the remainder of a swamp with deposits of the Pleistocene and Holocene eras, and were freed by scraping carefully a hard soil block.
The lithic artifacts manufactured by Clovis people to hunt great animals, were located a few centimeters under the gomphothere discovered in previous field seasons part of the research project conducted by the INAH, the University of Arizona and the National Geographic Society.
http://www.artdaily.org/index.asp?int_sec=2&int_new=44345
(Submitted by Terry W. Colvin)
Finding Would Reveal Contact between Humans and Gomphotheres in North America
Tuesday, February 1, 2011
MEXICO CITY.- Mexican Archaeologists discovered 3 Clovis projectile heads associated to remains of gomphotheres with an age of at least 12,000 years, in the northern region of the Mexican state of Sonora. The finding is relevant because these are the first evidences in North America of this extinct animal linked to the human species.
The finding opens the possibility of the coexistence of humankind with gomphotheres, animals similar to mammoths, but smaller, in this region of America, which contrasts with theories that declare that this species disappeared 30,000 years ago in this region of America and did not coexist with humans.
The discovery took place in early January 2011 in El Fin del Mundo, Sonora by researchers from the National Institute of Anthropology and History (INAH), during the third field season at the site identified as a hunting and quartering area during the Pleistocene.
This finding completes a scene in which archaeologists visualized how Clovis groups hunted this elephant ancestor. “This is an unprecedented finding in Mexico since it is the first time that projectile heads are found associated to a bone bed of this kind of proboscides.
“There is no other Clovis archaeological site where gomphotheres have been found, not even in the United States, where most important Clovis Culture findings have been registered, and these vestiges are dated between 10,600 and 11,600 years” informed archaeologist Guadalupe Sanchez, director of the Fin del Mundo Research Project.
“The discovery took place in the same archaeological context where in 2008 gomphothere bones and different lithic tools were found on the surface, among them, a quartz crystal Clovis head”.
Clovis people are also known as hunters of mammoths, one of 3 proboscide species that lived in America, being the other 2 the mastodon and the gomphothere. The last was the smallest and the earliest to appear in the Americas.
Gomphotheres have only been found associated to humans in South America, and the southernmost Clovis heads were found in Costa Rica; human evidence associated with proboscides was limited mastodons and mammoths, until now.
The INAH archaeologist Natalia Martinez, head of the field research, explained that Clovis projectile heads were discovered in the point named Localidad 1, the remainder of a swamp with deposits of the Pleistocene and Holocene eras, and were freed by scraping carefully a hard soil block.
The lithic artifacts manufactured by Clovis people to hunt great animals, were located a few centimeters under the gomphothere discovered in previous field seasons part of the research project conducted by the INAH, the University of Arizona and the National Geographic Society.
http://www.artdaily.org/index.asp?int_sec=2&int_new=44345
(Submitted by Terry W. Colvin)
MEXICO CITY.- Mexican Archaeologists discovered 3 Clovis projectile heads associated to remains of gomphotheres with an age of at least 12,000 years, in the northern region of the Mexican state of Sonora. The finding is relevant because these are the first evidences in North America of this extinct animal linked to the human species.
The finding opens the possibility of the coexistence of humankind with gomphotheres, animals similar to mammoths, but smaller, in this region of America, which contrasts with theories that declare that this species disappeared 30,000 years ago in this region of America and did not coexist with humans.
The discovery took place in early January 2011 in El Fin del Mundo, Sonora by researchers from the National Institute of Anthropology and History (INAH), during the third field season at the site identified as a hunting and quartering area during the Pleistocene.
This finding completes a scene in which archaeologists visualized how Clovis groups hunted this elephant ancestor. “This is an unprecedented finding in Mexico since it is the first time that projectile heads are found associated to a bone bed of this kind of proboscides.
“There is no other Clovis archaeological site where gomphotheres have been found, not even in the United States, where most important Clovis Culture findings have been registered, and these vestiges are dated between 10,600 and 11,600 years” informed archaeologist Guadalupe Sanchez, director of the Fin del Mundo Research Project.
“The discovery took place in the same archaeological context where in 2008 gomphothere bones and different lithic tools were found on the surface, among them, a quartz crystal Clovis head”.
Clovis people are also known as hunters of mammoths, one of 3 proboscide species that lived in America, being the other 2 the mastodon and the gomphothere. The last was the smallest and the earliest to appear in the Americas.
Gomphotheres have only been found associated to humans in South America, and the southernmost Clovis heads were found in Costa Rica; human evidence associated with proboscides was limited mastodons and mammoths, until now.
The INAH archaeologist Natalia Martinez, head of the field research, explained that Clovis projectile heads were discovered in the point named Localidad 1, the remainder of a swamp with deposits of the Pleistocene and Holocene eras, and were freed by scraping carefully a hard soil block.
The lithic artifacts manufactured by Clovis people to hunt great animals, were located a few centimeters under the gomphothere discovered in previous field seasons part of the research project conducted by the INAH, the University of Arizona and the National Geographic Society.
http://www.artdaily.org/index.asp?int_sec=2&int_new=44345
(Submitted by Terry W. Colvin)
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
Friday, January 7, 2011
Sabretooth cats threatened most ancient human ancestor
3 January 2011
By Paul Rincon Science reporter, BBC News
Humankind's oldest known ancestor probably lived in fear of several large sabretooth cats that roamed the same ancient lakeside habitat in Africa.
Palaeontologists have identified two new sabretooth species among fossils unearthed at Toros Menalla in Chad.
In 2001, a team unearthed remains of a seven million-year-old human-like creature - or hominid - known as "Toumai" at the central African site.
Its discoverers argue that Toumai is the oldest hominid known to science.
The fossilised skull of Toumai (which means "hope of life" in the local Dazaga language of Chad) was found in the Djurab desert by a team led by Michael Brunet of the University of Poitiers, France.
The position of a hole at the bottom of the skull called the foramen magnum suggests that Toumai (Sahelanthropus tchadensis) walked upright - an important signature of the human lineage.
The brainstem enters and exits the skull through this hole; in great apes, it is positioned more towards the back of the skull. But in hominids - including Toumai - it is placed more towards the front of the skull.
The ancient fossil caused a worldwide sensation when it was unveiled in the pages of Nature journal in 2002.
However, the interpretation of Toumai as a human relative is controversial. The skull was distorted and, if any other parts of the skeleton happen to exist, none has yet been published in the scientific literature. It is also older than the date when genetics says that the human and chimp lineages diverged.
Predator's playground
Nevertheless, palaeontologists have been busy studying the abundant fossil material unearthed at the site, steadily building a picture of the environment in which Sahelanthropus eked out its existence.
In Late Miocene times, this area of Chad must have had a lake, because palaeontologists have found the fossilised remains of fish, amphibians and crocodiles.
But they have also found evidence of grasslands, gallery forest and a desert.
Researchers have discovered the fossilised remains of a wide variety of carnivorous mammals at Toros Menalla. Ending up in the sharp jaws of a predator must have been an ever-present threat for primates like Toumai.
Palaentologists had already reported finding remains of a large sabretooth cat from Toros Menalla known as Machairodus kabir which weighed in at 350-490kg.
Writing in the journal Comptes Rendus Palevol, Louis de Bonis from Poitiers University and colleagues add two new sabretooth species to the growing list of carnivores that stalked this region of central Africa in late Miocene times.
The big cat remains were unearthed during recent field expeditions and have been identified as new species belonging to the genus Lokotunjailurus and the genus Megantereon.
Forest refuge
Patrick Vignaud, director of Poitier University's Institute of Palaeo-primatology and Human Palaeontology, told BBC News the cats were about the same size as modern lions.
"With our present data, we don't know what precisely the interactions were between a primate and a big carnivore. But probably these interactions were not so friendly," said Professor Vignaud.
He told BBC News: "Sabretooths hunted all mammals; bovids, equids... and primates. The interactions were also more 'psychological', exercising a stress on potential prey. We can't prove it but it's probably important because in that case, primates had to live near closed environments like gallery forest."
While ancient primates like Sahelanthropus tchadensis gave sabretooth cats a wide berth, they may also have depended on these big carnivores - and others - for their survival.
Sabretooths would have hunted large herbivorous mammals, and probably left enough meat on their kills for scavengers like the jackal-sized Hyaenictherium and perhaps even primates like Sahelanthropus.
Some researchers have proposed that Toumai is more closely related to chimpanzees or gorillas. Even if this were the case, the discovery would be of great significance, as virtually no fossil ancestors of these great apes are known from Africa.
http://www.bbc.co.uk/news/science-environment-11979934
By Paul Rincon Science reporter, BBC News
Humankind's oldest known ancestor probably lived in fear of several large sabretooth cats that roamed the same ancient lakeside habitat in Africa.
Palaeontologists have identified two new sabretooth species among fossils unearthed at Toros Menalla in Chad.
In 2001, a team unearthed remains of a seven million-year-old human-like creature - or hominid - known as "Toumai" at the central African site.
Its discoverers argue that Toumai is the oldest hominid known to science.
The fossilised skull of Toumai (which means "hope of life" in the local Dazaga language of Chad) was found in the Djurab desert by a team led by Michael Brunet of the University of Poitiers, France.
The position of a hole at the bottom of the skull called the foramen magnum suggests that Toumai (Sahelanthropus tchadensis) walked upright - an important signature of the human lineage.
The brainstem enters and exits the skull through this hole; in great apes, it is positioned more towards the back of the skull. But in hominids - including Toumai - it is placed more towards the front of the skull.
The ancient fossil caused a worldwide sensation when it was unveiled in the pages of Nature journal in 2002.
However, the interpretation of Toumai as a human relative is controversial. The skull was distorted and, if any other parts of the skeleton happen to exist, none has yet been published in the scientific literature. It is also older than the date when genetics says that the human and chimp lineages diverged.
Predator's playground
Nevertheless, palaeontologists have been busy studying the abundant fossil material unearthed at the site, steadily building a picture of the environment in which Sahelanthropus eked out its existence.
In Late Miocene times, this area of Chad must have had a lake, because palaeontologists have found the fossilised remains of fish, amphibians and crocodiles.
But they have also found evidence of grasslands, gallery forest and a desert.
Researchers have discovered the fossilised remains of a wide variety of carnivorous mammals at Toros Menalla. Ending up in the sharp jaws of a predator must have been an ever-present threat for primates like Toumai.
Palaentologists had already reported finding remains of a large sabretooth cat from Toros Menalla known as Machairodus kabir which weighed in at 350-490kg.
Writing in the journal Comptes Rendus Palevol, Louis de Bonis from Poitiers University and colleagues add two new sabretooth species to the growing list of carnivores that stalked this region of central Africa in late Miocene times.
The big cat remains were unearthed during recent field expeditions and have been identified as new species belonging to the genus Lokotunjailurus and the genus Megantereon.
Forest refuge
Patrick Vignaud, director of Poitier University's Institute of Palaeo-primatology and Human Palaeontology, told BBC News the cats were about the same size as modern lions.
"With our present data, we don't know what precisely the interactions were between a primate and a big carnivore. But probably these interactions were not so friendly," said Professor Vignaud.
He told BBC News: "Sabretooths hunted all mammals; bovids, equids... and primates. The interactions were also more 'psychological', exercising a stress on potential prey. We can't prove it but it's probably important because in that case, primates had to live near closed environments like gallery forest."
While ancient primates like Sahelanthropus tchadensis gave sabretooth cats a wide berth, they may also have depended on these big carnivores - and others - for their survival.
Sabretooths would have hunted large herbivorous mammals, and probably left enough meat on their kills for scavengers like the jackal-sized Hyaenictherium and perhaps even primates like Sahelanthropus.
Some researchers have proposed that Toumai is more closely related to chimpanzees or gorillas. Even if this were the case, the discovery would be of great significance, as virtually no fossil ancestors of these great apes are known from Africa.
http://www.bbc.co.uk/news/science-environment-11979934
Sabretooth cats threatened most ancient human ancestor
3 January 2011
By Paul Rincon Science reporter, BBC News
Humankind's oldest known ancestor probably lived in fear of several large sabretooth cats that roamed the same ancient lakeside habitat in Africa.
Palaeontologists have identified two new sabretooth species among fossils unearthed at Toros Menalla in Chad.
In 2001, a team unearthed remains of a seven million-year-old human-like creature - or hominid - known as "Toumai" at the central African site.
Its discoverers argue that Toumai is the oldest hominid known to science.
The fossilised skull of Toumai (which means "hope of life" in the local Dazaga language of Chad) was found in the Djurab desert by a team led by Michael Brunet of the University of Poitiers, France.
The position of a hole at the bottom of the skull called the foramen magnum suggests that Toumai (Sahelanthropus tchadensis) walked upright - an important signature of the human lineage.
The brainstem enters and exits the skull through this hole; in great apes, it is positioned more towards the back of the skull. But in hominids - including Toumai - it is placed more towards the front of the skull.
The ancient fossil caused a worldwide sensation when it was unveiled in the pages of Nature journal in 2002.
However, the interpretation of Toumai as a human relative is controversial. The skull was distorted and, if any other parts of the skeleton happen to exist, none has yet been published in the scientific literature. It is also older than the date when genetics says that the human and chimp lineages diverged.
Predator's playground
Nevertheless, palaeontologists have been busy studying the abundant fossil material unearthed at the site, steadily building a picture of the environment in which Sahelanthropus eked out its existence.
In Late Miocene times, this area of Chad must have had a lake, because palaeontologists have found the fossilised remains of fish, amphibians and crocodiles.
But they have also found evidence of grasslands, gallery forest and a desert.
Researchers have discovered the fossilised remains of a wide variety of carnivorous mammals at Toros Menalla. Ending up in the sharp jaws of a predator must have been an ever-present threat for primates like Toumai.
Palaentologists had already reported finding remains of a large sabretooth cat from Toros Menalla known as Machairodus kabir which weighed in at 350-490kg.
Writing in the journal Comptes Rendus Palevol, Louis de Bonis from Poitiers University and colleagues add two new sabretooth species to the growing list of carnivores that stalked this region of central Africa in late Miocene times.
The big cat remains were unearthed during recent field expeditions and have been identified as new species belonging to the genus Lokotunjailurus and the genus Megantereon.
Forest refuge
Patrick Vignaud, director of Poitier University's Institute of Palaeo-primatology and Human Palaeontology, told BBC News the cats were about the same size as modern lions.
"With our present data, we don't know what precisely the interactions were between a primate and a big carnivore. But probably these interactions were not so friendly," said Professor Vignaud.
He told BBC News: "Sabretooths hunted all mammals; bovids, equids... and primates. The interactions were also more 'psychological', exercising a stress on potential prey. We can't prove it but it's probably important because in that case, primates had to live near closed environments like gallery forest."
While ancient primates like Sahelanthropus tchadensis gave sabretooth cats a wide berth, they may also have depended on these big carnivores - and others - for their survival.
Sabretooths would have hunted large herbivorous mammals, and probably left enough meat on their kills for scavengers like the jackal-sized Hyaenictherium and perhaps even primates like Sahelanthropus.
Some researchers have proposed that Toumai is more closely related to chimpanzees or gorillas. Even if this were the case, the discovery would be of great significance, as virtually no fossil ancestors of these great apes are known from Africa.
http://www.bbc.co.uk/news/science-environment-11979934
By Paul Rincon Science reporter, BBC News
Humankind's oldest known ancestor probably lived in fear of several large sabretooth cats that roamed the same ancient lakeside habitat in Africa.
Palaeontologists have identified two new sabretooth species among fossils unearthed at Toros Menalla in Chad.
In 2001, a team unearthed remains of a seven million-year-old human-like creature - or hominid - known as "Toumai" at the central African site.
Its discoverers argue that Toumai is the oldest hominid known to science.
The fossilised skull of Toumai (which means "hope of life" in the local Dazaga language of Chad) was found in the Djurab desert by a team led by Michael Brunet of the University of Poitiers, France.
The position of a hole at the bottom of the skull called the foramen magnum suggests that Toumai (Sahelanthropus tchadensis) walked upright - an important signature of the human lineage.
The brainstem enters and exits the skull through this hole; in great apes, it is positioned more towards the back of the skull. But in hominids - including Toumai - it is placed more towards the front of the skull.
The ancient fossil caused a worldwide sensation when it was unveiled in the pages of Nature journal in 2002.
However, the interpretation of Toumai as a human relative is controversial. The skull was distorted and, if any other parts of the skeleton happen to exist, none has yet been published in the scientific literature. It is also older than the date when genetics says that the human and chimp lineages diverged.
Predator's playground
Nevertheless, palaeontologists have been busy studying the abundant fossil material unearthed at the site, steadily building a picture of the environment in which Sahelanthropus eked out its existence.
In Late Miocene times, this area of Chad must have had a lake, because palaeontologists have found the fossilised remains of fish, amphibians and crocodiles.
But they have also found evidence of grasslands, gallery forest and a desert.
Researchers have discovered the fossilised remains of a wide variety of carnivorous mammals at Toros Menalla. Ending up in the sharp jaws of a predator must have been an ever-present threat for primates like Toumai.
Palaentologists had already reported finding remains of a large sabretooth cat from Toros Menalla known as Machairodus kabir which weighed in at 350-490kg.
Writing in the journal Comptes Rendus Palevol, Louis de Bonis from Poitiers University and colleagues add two new sabretooth species to the growing list of carnivores that stalked this region of central Africa in late Miocene times.
The big cat remains were unearthed during recent field expeditions and have been identified as new species belonging to the genus Lokotunjailurus and the genus Megantereon.
Forest refuge
Patrick Vignaud, director of Poitier University's Institute of Palaeo-primatology and Human Palaeontology, told BBC News the cats were about the same size as modern lions.
"With our present data, we don't know what precisely the interactions were between a primate and a big carnivore. But probably these interactions were not so friendly," said Professor Vignaud.
He told BBC News: "Sabretooths hunted all mammals; bovids, equids... and primates. The interactions were also more 'psychological', exercising a stress on potential prey. We can't prove it but it's probably important because in that case, primates had to live near closed environments like gallery forest."
While ancient primates like Sahelanthropus tchadensis gave sabretooth cats a wide berth, they may also have depended on these big carnivores - and others - for their survival.
Sabretooths would have hunted large herbivorous mammals, and probably left enough meat on their kills for scavengers like the jackal-sized Hyaenictherium and perhaps even primates like Sahelanthropus.
Some researchers have proposed that Toumai is more closely related to chimpanzees or gorillas. Even if this were the case, the discovery would be of great significance, as virtually no fossil ancestors of these great apes are known from Africa.
http://www.bbc.co.uk/news/science-environment-11979934
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