The field of epigenetics looks at chemical modifications to DNA, known as epigenetic marks, that influence which genes are expressed — or turned on or off. Some epigenetic marks stay in place throughout a person’s life, but others may be added or removed in response to environmental factors such as diet, disease and climate. If the modification is made to sperm or egg DNA, the changes could be inherited.
“By looking at epigenetic marks, we can better understand what genes are expressed during a person’s life and how different environmental stresses shaped physical traits and health across generations,” said UT Austin anthropology researcher Rick Smith, lead author of the study.
Previous studies of modern DNA looked at people who experienced famine in utero during World War II, revealing epigenetic changes related to diet, growth and metabolism. Similarly, other modern DNA studies have shown that some epigenetic marks are tied to cancer and may contribute to the development of the disease. Researchers say that investigating these marks in ancient DNA could improve understanding of the health of ancient populations.
Smith worked with Deborah Bolnick, a UT Austin associate professor of anthropology, and Cara Monroe, a Washington State University anthropologist, looking for an epigenetic mark known as cytosine methylation in the remains of 30 ancient humans from five archaeological sites in North America, ranging in age from 230 to more than 4,500 years old. The researchers successfully recovered methylation in 29 of the samples — a dramatic improvement over previous studies, Smith said.
Prior to this study, cytosine methylation had primarily been detected in isolated ancient remains — one Neanderthal and one Denisovan from Siberia, between 50,000 and 130,000 years old; a 4,000-year-old Paleo-Eskimo from Greenland; and a 26,000-year-old bison from Canada. Researchers have also identified methylation in barley samples from Egypt that are between 200 and 2,800 years old.
Unlike these previous studies of ancient DNA, Smith used a technique called bisulfite sequencing — a “gold standard” method commonly used to measure methylation in modern DNA, providing more precise measurements. Many researchers thought it wouldn’t yield results when applied to degraded ancient DNA, because it further degrades DNA. However, this research indicates that bisulfite sequencing can be successful when used on more recent and better-preserved DNA, Smith said.
“By studying methylation in ancient DNA from archaeological populations, not just isolated samples, we may gain insights into how past environments affected ancient societies,” Bolnick said. “Future research in ancient epigenetics should open a new window into the lives and experiences of people who lived long ago.”
Their research, which was partially funded by a Sigma Xi Grant-in-Aid of Research, appeared in the online edition of the journal PLOS ONE. The article is titled “Detection of Cytosine Methylation in Ancient DNA from Five Native American Populations Using Bisulfite Sequencing.”
Upper and lower jaw fossils recovered from the Woranso-Mille area of the Afar region of Ethiopia have been assigned to the new species Australopithecus deyiremeda. This hominin lived alongside the famous “Lucy’s” species, Australopithecus afarensis. The species will be described in the May 28, 2015 issue of the international scientific journal Nature.
Lucy’s species lived from 2.9 million years ago to 3.8 million years ago, overlapping in time with the new species Australopithecus deyiremeda. The new species is the most conclusive evidence for the contemporaneous presence of more than one closely related early human ancestor species prior to 3 million years ago. The species name “deyiremeda” (day-ihreme-dah) means “close relative” in the language spoken by the Afar people.
Australopithecus deyiremeda differs from Lucy’s species in terms of the shape and size of its thick-enameled teeth and the robust architecture of its lower jaws. The anterior teeth are also relatively small indicating that it probably had a different diet.
“The new species is yet another confirmation that Lucy’s species, Australopithecus afarensis, was not the only potential human ancestor species that roamed in what is now the Afar region of Ethiopia during the middle Pliocene,” said lead author and Woranso-Mille project team leader Dr. Yohannes Haile-Selassie, curator of physical anthropology at The Cleveland Museum of Natural History. “Current fossil evidence from the Woranso-Mille study area clearly shows that there were at least two, if not three, early human species living at the same time and in close geographic proximity.”
“The age of the new fossils is very well constrained by the regional geology, radiometric dating, and new paleomagnetic data,” said co-author Dr. Beverly Saylor of Case Western Reserve University. The combined evidence from radiometric, paleomagnetic, and depositional rate analyses yields estimated minimum and maximum ages of 3.3 and 3.5 million years.
“This new species from Ethiopia takes the ongoing debate on early hominin diversity to another level,” said Haile-Selassie. “Some of our colleagues are going to be skeptical about this new species, which is not unusual. However, I think it is time that we look into the earlier phases of our evolution with an open mind and carefully examine the currently available fossil evidence rather than immediately dismissing the fossils that do not fit our long-held hypotheses,” said Haile-Selassie.
Scientists have long argued that there was only one pre-human species at any given time between 3 and 4 million years ago, subsequently giving rise to another new species through time. This was what the fossil record appeared to indicate until the end of the 20th century. However, the naming of Australopithecus bahrelghazali from Chad and Kenyanthropus platyops from Kenya, both from the same time period as Lucy’s species, challenged this long-held idea. Although a number of researchers were skeptical about the validity of these species, the announcement by Haile-Selassie of the 3.4 million-year-old Burtele partial foot in 2012 cleared some of the skepticism on the likelihood of multiple early hominin species in the 3 to 4 million-year range.
The Burtele partial fossil foot did not belong to a member of Lucy’s species. However, despite the similarity in geological age and close geographic proximity, the researchers have not assigned the partial foot to the new species due to lack of clear association. Regardless, the new species Australopithecus deyiremeda incontrovertibly confirms that multiple species did indeed co-exist during this time period.
This discovery has important implications for our understanding of early hominin ecology. It also raises significant questions, such as how multiple early hominins living at the same time and geographic area might have used the shared landscape and available resources.
Discovery of Australopithecus deyiremeda:
The holotype (type specimen) of Australopithecus deyiremeda is an upper jaw with teeth discovered on March 4, 2011, on top of a silty clay surface at one of the Burtele localities. The paratype lower jaws were also surface discoveries found on March 4 and 5, 2011, at the same locality as the holotype and another nearby locality called Waytaleyta. The holotype upper jaw was found in one piece (except for one of the teeth which was found nearby), whereas the mandible was recovered in two halves that were found about two meters apart from each other. The other mandible was found about 2 kilometers east of where the Burtele specimens were found.
Location of the Discovery:
The fossil specimens were found in the Woranso-Mille Paleontological Project study area located in the central Afar region of Ethiopia about 325 miles (520 kilometers) northeast of the capital Addis Ababa and 22 miles (35 kilometers) north of Hadar (“Lucy’s” site). Burtele and Waytaleyta are local names for the areas where the holotype and paratypes were found and they are located in the Mille district, Zone 1 of the Afar Regional State.
The Woranso-Mille Project:
The Woranso-Mille Paleontological project conducts field and laboratory work in Ethiopia every year. This multidisciplinary project is led by Dr. Yohannes Haile-Selassie of The Cleveland Museum of Natural History. Additional co-authors of this research include: Dr. Luis Gibert of University of Barcelona (Spain), Dr. Stephanie Melillo of the Max Planck Institute (Leipzig, Germany), Dr. Timothy M. Ryan of Pennsylvania State University, Dr. Mulugeta Alene of Addis Ababa University (Ethiopia), Drs. Alan Deino and Gary Scott of the Berkeley Geochronology Center, Dr. Naomi E. Levin of Johns Hopkins University, and Dr. Beverly Z. Saylor of Case Western Reserve University. Graduate and undergraduate students from Ethiopia and the United States of America also participated in the field and laboratory activities of the project.
The project, which was funded by the Wellcome Trust, was led by Professor Mark Jobling from the University of Leicester’s Department of Genetics and the study is published in the prestigious journal Nature Communications.
The research team determined the DNA sequences of a large part of the Y chromosome, passed exclusively from fathers to sons, in 334 men from 17 European and Middle Eastern populations.
This research used new methods for analysing DNA variation that provides a less biased picture of diversity, and also a better estimate of the timing of population events.
This allowed the construction of a genealogical tree of European Y chromosomes that could be used to calculate the ages of branches. Three very young branches, whose shapes indicate recent expansions, account for the Y chromosomes of 64% of the men studied.
Professor Jobling said: “The population expansion falls within the Bronze Age, which involved changes in burial practices, the spread of horse-riding and developments in weaponry. Dominant males linked with these cultures could be responsible for the Y chromosome patterns we see today.”
In addition, past population sizes were estimated, and showed that a continuous swathe of populations from the Balkans to the British Isles underwent an explosion in male population size between 2000 and 4000 years ago.
This contrasts with previous results for the Y chromosome, and also with the picture presented by maternally-inherited mitochondrial DNA, which suggests much more ancient population growth.
Previous research has focused on the proportion of modern Europeans descending from Paleolithic – Old Stone Age – hunter-gatherer populations or more recent Neolithic farmers, reflecting a transition that began about 10,000 years ago.
Chiara Batini from the University of Leicester’s Department of Genetics, lead author of the study, added: “Given the cultural complexity of the Bronze Age, it’s difficult to link a particular event to the population growth that we infer. But Y-chromosome DNA sequences from skeletal remains are becoming available, and this will help us to understand what happened, and when.”
The study ‘Large-scale recent expansion of European patrilineages shown by population resequencing’ is published in Nature Communications.
It seems, however, that these social media applications do potentially more harm than good – by allowing archaeology and the future of collective cultural heritage to be swept away by naïve initiatives without strategic oversight. The archaeological record and the archaeological profession are at stake, local communities face unequal access to their own heritage and archaeologists themselves become all too often a subject of abuse and exploitation.
An article published today in Open Archaeology focuses on the current state of the social web in the development of archaeological practice, and reflects on various conscientious activities aimed both at challenging current online interactions, as well as at positioning archaeologists as more informed innovators of the web.
Sara Perry and Nicole Beale, both from The University of York, surveyed the field in search of active social web initiatives in archaeology, studying their development and evaluation and assessing their impacts on other people, on cultural heritage itself and on the world at large. They found out that archaeologists have been drawing on social media and crowdsourcing/crowdfunding tools since their appearance on the web, and also that despite this long history of involvement, there is little evidence that they are aware of their (often dangerous) impacts.
It seems that these social web applications have not only put archaeologists themselves in danger, exposing them to severe online harassment and abuse, but that they are also draw local communities into exploitative labour practices, and seemingly enable a devolution of responsibility for, and weakened oversight of, the archaeological record. In so doing, the use of the web appears to be relieving the government and the cultural custodians of their duties to protect and conserve the historic environment for the future.
The authors argue that archaeology could adopt a more obvious social justice stance, using web-based media to advocate for cultural change and to bring attention to the short-sighted politics which are threatening our collective cultural heritage.
Photogrammetry is a method that uses two-dimensional images of an archaeological find to construct a 3D model.
You don’t need and special glasses or advanced equipment to use make use of this new technique. Together with precise measurements of the excavation, photogrammetry can create a complete detailed map of an archaeological excavation site.
“This is still a very new technique,” say archaeologists Raymond Sauvage and Fredrik Skoglund of the Norwegian University of Science and Technology’s University Museum.
Photogrammetry is in many ways much more precise than older, more time-consuming methods.
This method is already being put to use by archaeologists. When a possible Viking grave was found in Skaun in Sør-Trøndelag in 2014, the excavation site was mapped using photogrammetry.
The manner in which artefacts are found, how deeply the are buried and where they are placed in relation to each other can provide a lot of information to archaeologists studying a site.
Photogrammetry also makes it easier for archaeologists to share their findings with others. The 3D models that are produced can be saved as normal PDF files, which can be sent to colleagues for input.
The two archaeologists are very enthusiastic. A Russian company has developed the program that they’re using at the museum. The program is easy to use and gives good results. The development and use of the technique has exploded in recent years.
“There’s a lot more interest in photogrammetry now. The new program is readily available and inexpensive,” says Sauvage.
He explains that it provides the kind of quality and detail that you could only dream of a few years ago. Even though the method requires some work, it still saves a lot of time.
“In one day, you can get three million measurement points. Before, we were satisfied with 3000,” he says.
And those 3000 points could take a long time to find. This method can save archaeologists weeks of work with tape measures, sketching paper and cameras. The practical work in the field goes much quicker.
“This frees up a lot more time for things like research,” Skoglund says.
Similar results have been achieved in the past using laser equipment and early versions of a photogrammetry program. But this has been very expensive, and takes a lot of time and resources.
The new program only costs a few hundred euros, meaning that it is much more widely available.
With a photogrammetry program, three or four pictures from different angles are enough to make a simple 3D model, although more images will provide a higher quality model. You can use any normal camera.
“The more images, the better the quality,” Sauvage says.
It is also possible to use images of old finds to build a 3D model based on them. For example, you could make a model using photos from previous excavations of Viking graves, and use this to explore how an excavation site changes over time.
Marine archaeologist Skoglund has tried this with the Dutch ship “De Grawe Adler” (the Grey Eagle), which sank in 1696 by Strømsholmen in Hustadvika, on the coast of central Norway and was discovered in 1982 when dredging for sand destroyed parts of the ship.
“I swam along the whole length of the wreck a few years ago and took pictures,” Skoglund says.
He did so with out ever considering the possibility of making a 3D model of the wreck. The fact that the photos were taken underwater makes it slightly harder to put them together, but it is by no means impossible.
If the results are precise enough, they can be used to monitor the decomposition of the ship. Finds under water tend to be particularly fragile, but decomposition can be difficult to see. You can’t just dive down every few years to make sure that everything is OK. With this new method, the decomposition can be measured much more precisely, and appropriate protection measures can be put in place.
The next step is likely to be able to put on a pair of 3D-glasses and virtually walk into an excavation site, although that may be a few years in coming.
There is one challenge, however — storing measurements digitally in a manner that will be useful for generations to come. Archaeologists working today are behind measurements and notes on excavations that may be used hundreds of years in the future. A paper photo taken 100 years ago is just as good now as it was then, as long as you have it on hand. But nobody knows if a PDF file will be of use in year 2115. But this is a challenge facing all information that is stored digitally. And it’s something that we can’t overcome.
Welcome to Archaeology in Oceania. In this series Rhys Booth will discuss new discoveries, shed light on current theories and pose topical debates surrounding the archaeology of Australia and beyond.
Today, Rhys examines sea shanties.
Today, Bethany and I play ‘Valiant Hearts: The Great War’ on the xBox 360.
This is a remarkably beautiful game crammed with facts, artefacts and clever observations about the Great War 1914 – 1918.
The analyses show that she was born and raised outside Denmark’s current borders, and strontium isotope analyses of the girl’s hair and a thumb nail also show that she travelled great distances the last two years of her life.
The wool from the Egtved Girl’s clothing, the blanket she was covered with, and the oxhide she was laid to rest on in the oak coffin all originate from a location outside present-day Denmark. The combination of the different provenance analyses indicates that the Egtved Girl, her clothing, and the oxhide come from Schwarzwald (“the Black Forest”) in South West Germany – as do the cremated remains of a six-year-old child who was buried with the Egtved Girl. The girl’s coffin dates the burial to a summer day in the year 1370 BC.
It is senior researcher Karin Margarita Frei, from the National Museum of Denmark and Centre for Textile Research at the University of Copenhagen, who has analysed the Egtved Girl’s strontium isotope signatures. The analyses have been carried out in collaboration with Kristian Kristiansen from the University of Gothenburg and the Department of Geosciences and Natural Resource Management and the Centre for GeoGenetics, both University of Copenhagen.
The research has been possible through the support of The Danish National Research Foundation, European Research Council, the Carlsberg Foundation and L’Oréal Denmark-UNESCO For Women in Science Award.
The results have just been published in Scientific Reports.
The girl’s movements mapped month by month
Strontium is an element which exists in the earth’s crust, but its prevalence is subject to geological variation. Humans, animals, and plants absorb strontium through water and food. By measuring the strontium isotopic signatures in archaeological remains, researchers can determine where humans and animals lived, and where plants grew because of their strontium isotope signatures. In that sense, strontium serves as a kind of GPS for scientists.
“I have analysed the strontium isotopic signatures of the enamel from one of the Egtved Girl’s first molars, which was fully formed/crystallized when she was three or four years old, and the analysis tells us that she was born and lived her first years in a region that is geologically older than and different from the peninsula of Jutland in Denmark,” Karin Margarita Frei says.
Karin Margarita Frei has also traced the last two years of the Egtved Girl’s life by examining the strontium isotopic signatures in the girl’s 23-centimetre-long hair. The analysis shows that she had been on a long journey shortly before she died, and this is the first time that researchers have been able to so accurately track a prehistoric person’s movements.
“If we consider the last two years of the girl’s life, we can see that, 13 to 15 months before her death, she stayed in a place with a strontium isotope signature very similar to the one that characterizes the area where she was born. Then she moved to an area that may well have been Jutland. After a period of c. 9 to 10 months there, she went back to the region she originally came from and stayed there for four to six months before she travelled to her final resting place, Egtved. Neither her hair nor her thumb nail contains a strontium isotopic signatures which indicates that she returned to Scandinavia until very shortly before she died. As an area’s strontium isotopic signature is only detectable in human hair and nails after a month, she must have come to “Denmark” and “Egtved” about a month before she passed away,” Karin Margarita Frei explains.
The Black Forest Girl
If the Egtved Girl was not born in Jutland, then where did she come from? Karin Margarita Frei suggests that she came from South West Germany, more specifically the Black Forest, which is located 500 miles south of Egtved.
Considered in isolation, the Egtved Girl’s strontium isotope signature could indicate that she came from Sweden, Norway or Western or Southern Europe. She could also come from the island Bornholm in the Baltic Sea. But when Karin Margarita Frei combines the girl’s strontium isotopic signatures with that of her clothing, she can pinpoint the girl’s place of origin relatively accurately.
“The wool that her clothing was made from did not come from Denmark and the strontium isotope values vary greatly from wool thread to wool thread. This proves that the wool was made from sheep that either grazed in different geographical areas or that they grazed in one vast area with very complex geology, and Black Forest’s bedrock is characterized by a similarly heterogeneous strontium isotopic range,” Karin Margarita Frei says.
That the Egtved Girl in all probability came from the Black Forest region in Germany comes as no surprise to professor Kristian Kristiansen from the University of Gothenburg; the archaeological finds confirm that there were close relations between Denmark and Southern Germany in the Bronze Age.
“In Bronze Age Western Europe, Southern Germany and Denmark were the two dominant centres of power, very similar to kingdoms. We find many direct connections between the two in the archaeological evidence, and my guess is that the Egtved Girl was a Southern German girl who was given in marriage to a man in Jutland so as to forge an alliance between two powerful families,” Kristian Kristiansen says.
According to him, Denmark was rich in amber and traded amber for bronze. In Mycenaean Greece and in the Middle East, Baltic amber was as coveted as gold, and, through middlemen in Southern Germany, large quantities of amber were transported to the Mediterranean, and large quantities of bronze came to Denmark as payment. In the Bronze Age, bronze was as valuable a raw material as oil is today so Denmark became one of the richest areas of Northern Europe.
“Amber was the engine of Bronze Age economy, and in order to keep the trade routes going, powerful families would forge alliances by giving their daughters in marriage to each other and letting their sons be raised by each other as a kind of security,” Kristian Kristiansen says.
A great number of Danish Bronze Age graves contain human remains that are as well-preserved as those found the Egtved Girl’s grave. Karin Margarita Frei and Kristian Kristiansen plan to examine these remains with a view to analysing their strontium isotope signatures.
The tools, whose makers may or may not have been some sort of human ancestor, push the known date of such tools back by 700,000 years; they also may challenge the notion that our own most direct ancestors were the first to bang two rocks together to create a new technology.
The discovery is the first evidence that an even earlier group of proto-humans may have had the thinking abilities needed to figure out how to make sharp-edged tools. The stone tools mark “a new beginning to the known archaeological record,” say the authors of a new paper about the discovery, published today in the leading scientific journal Nature.
“The whole site’s surprising, it just rewrites the book on a lot of things that we thought were true,” said geologist Chris Lepre of the Lamont-Doherty Earth Observatory and Rutgers University, a co-author of the paper who precisely dated the artifacts.
The tools “shed light on an unexpected and previously unknown period of hominin behavior and can tell us a lot about cognitive development in our ancestors that we can’t understand from fossils alone,” said lead author Sonia Harmand, of the Turkana Basin Institute at Stony Brook University and the Universite? Paris Ouest Nanterre.
Hominins are a group of species that includes modern humans, Homo sapiens, and our closest evolutionary ancestors. Anthropologists long thought that our relatives in the genus Homo – the line leading directly to Homo sapiens – were the first to craft such stone tools. But researchers have been uncovering tantalizing clues that some other, earlier species of hominin, distant cousins, if you will, might have figured it out.
The researchers do not know who made these oldest of tools. But earlier finds suggest a possible answer: The skull of a 3.3-million-year-old hominin, Kenyanthropus platytops, was found in 1999 about a kilometer from the tool site. A K. platyops tooth and a bone from a skull were discovered a few hundred meters away, and an as-yet unidentified tooth has been found about 100 meters away.
The precise family tree of modern humans is contentious, and so far, no one knows exactly how K. platyops relates to other hominin species. Kenyanthropus predates the earliest known Homo species by a half a million years. This species could have made the tools; or, the toolmaker could have been some other species from the same era, such as Australopithecus afarensis, or an as-yet undiscovered early type of Homo.
Lepre said a layer of volcanic ash below the tool site set a “floor” on the site’s age: It matched ash elsewhere that had been dated to about 3.3 million years ago, based on the ratio of argon isotopes in the material. To more sharply define the time period of the tools, Lepre and co-author and Lamont-Doherty colleague Dennis Kent examined magnetic minerals beneath, around and above the spots where the tools were found.
The Earth’s magnetic field periodically reverses itself, and the chronology of those changes is well documented going back millions of years. “We essentially have a magnetic tape recorder that records the magnetic field … the music of the outer core,” Kent said. By tracing the variations in the polarity of the samples, they dated the site to 3.33 million to 3.11 million years.
Lepre’s wife and another co-author, Rhoda Quinn of Rutgers, studied carbon isotopes in the soil, which along with animal fossils at the site allowed researchers to reconstruct the area’s vegetation. This led to another surprise: The area was at that time a partially wooded, shrubby environment. Conventional thinking has been that sophisticated tool-making came in response to a change in climate that led to the spread of broad savannah grasslands, and the consequent evolution of large groups of animals that could serve as a source of food for human ancestors.
One line of thinking is that hominins started knapping – banging one rock against another to make sharp-edged stones – so they could cut meat off of animal carcasses, said paper co-author Jason Lewis of the Turkana Basin Institute and Rutgers. But the size and markings of the newly discovered tools “suggest they were doing something different as well, especially if they were in a more wooded environment with access to various plant resources,” Lewis said. The researchers think the tools could have been used for breaking open nuts or tubers, bashing open dead logs to get at insects inside, or maybe something not yet thought of.
“The capabilities of our ancestors and the environmental forces leading to early stone technology are a great scientific mystery,” said Richard Potts, director of the Human Origins Program at the Smithsonian’s National Museum of Natural History, who was not involved in the research. The newly dated tools “begin to lift the veil on that mystery, at an earlier time than expected,” he said.
Potts said he had examined the stone tools during a visit to Kenya in February.
“Researchers have thought there must be some way of flaking stone that preceded the simplest tools known until now,” he said. “Harmand’s team shows us just what this even simpler altering of rocks looked like before technology became a fundamental part of early human behavior.”
Ancient stone artifacts from East Africa were first uncovered at Olduvai Gorge in Tanzania in the mid-20th century, and those tools were later associated with fossil discoveries in the 1960s of the early human ancestor Homo habilis. That species has been dated to 2.1 million to 1.5 million years ago.
Subsequent finds have pushed back the dates of humans’ evolutionary ancestors, and of stone tools, raising questions about who first made that cognitive leap. The discovery of a partial lower jaw in the Afar region of Ethiopia, announced on March 4, pushes the fossil record for the genus Homo to 2.8 million years ago. Evidence from recent papers, the authors note, suggests that there is anatomical evidence that Homo had evolved into several distinct lines by 2 million years ago.
There is some evidence of more primitive tool use going back even before the new find. In 2009, researchers at Dikika, Ethiopia, dug up 3.39 million-year-old animal bones marked with slashes and other cut marks, evidence that someone used stones to trim flesh from bone and perhaps crush bones to get at the marrow inside. That is the earliest evidence of meat and marrow consumption by hominins. No tools were found at the site, so it’s unclear whether the marks were made with crafted tools or simply sharp-edged stones. The only hominin fossil remains in the area dating to that time are from Australopithecus afarensis.
The new find came about almost by accident: Harmand and Lewis said that on the morning of July 9, 2011, they had wandered off on the wrong path, and climbed a hill to scout a fresh route back to their intended track. They wrote that they “could feel that something was special about this particular place.” They fanned out and surveyed a nearby patch of craggy outcrops. “By teatime,” they wrote, “local Turkana tribesman Sammy Lokorodi had helped [us] spot what [we] had come searching for.”
By the end of the 2012 field season, excavations at the site, named Lomekwi 3, had uncovered 149 stone artifacts tied to tool-making, from stone cores and flakes to rocks used for hammering and others possibly used as anvils to strike on.
The researchers tried knapping stones themselves to better understand how the tools they found might have been made. They concluded that the techniques used “could represent a technological stage between a hypothetical pounding-oriented stone tool use by an earlier hominin and the flaking-oriented knapping behavior of [later] toolmakers.” Chimpanzees and other primates are known to use a stone to hammer open nuts atop another stone. But using a stone for multiple purposes, and using one to crack apart another into a sharper tool, is more advanced behavior.
The find also has implications for understanding the evolution of the human brain. The toolmaking required a level of hand motor control that suggests that changes in the brain and spinal tract needed for such activity could have occurred before 3.3 million years ago, the authors said.
“This is a momentous and well-researched discovery,” said paleoanthropologist Bernard Wood of George Washington University, who was not involved in the study. “I have seen some of these artifacts in the flesh, and I am convinced they were fashioned deliberately.” Wood said he found it intriguing to see how different the tools are from so-called Oldowan stone tools, which up to now have been considered the oldest and most primitive.
Lepre, who has been conducting fieldwork in eastern Africa for about 15 years, said he arrived at the dig site about a week after the discovery. The site is several hours’ drive on rough roads from the nearest town, located in a hot, dry landscape he said is reminiscent of Arizona and New Mexico. Lepre collected chunks of sediment from a series of depths and brought them back to Lamont-Doherty for analysis. He and Kent used a bandsaw to trim the samples into sugar cube-size blocks and inserted them into a magnetometer, which measured the polarity of tiny grains of the minerals hematite and magnetite contained in the sediment.
“The magnetics pretty much clinches that the age is something like 3.3 million years old,” said Kent, who also is a professor at Rutgers.
Earlier dating work by Lepre and Kent helped lead to another landmark paper in 2011: a study that suggested Homo erectus, another precursor to modern humans, was using more advanced tool-making methods 1.8 million years ago, at least 300,000 years earlier than previously thought.
“I realized when you [figure out] these things, you don’t solve anything, you just open up new questions,” said Lepre. “I get excited, then realize there’s a lot more work to do.”
The Earth Institute at Columbia University – Header Image Credit: Sammy Lokorodi, a resident of Kenya’s northwestern desert who works as a fossil and artifact hunter, led the way to a trove of 3.3 million-year-old tools. – West Turkana Archaeological Project
The fossils were discovered while collecting ammonite fossils (a nautilus-like creature) from a marine rock unit known as the Cedar District Formation. The authors of the study describe the fossil as the partial left femur of a theropod dinosaur, the group of two-legged, carnivorous dinosaurs that includes Velociraptor, Tyrannosaurus rex, and modern birds. The fossil is 16.7 inches long and 8.7 inches wide, but would have been over three feet long when complete. The dinosaur is from the Late Cretaceous period and is approximately 80 million years old.
Although incomplete, the authors believe it is a theropod dinosaur femur due to the hollow middle cavity of the bone, where marrow was present, which is unique to theropods during this time period. The authors also point to a feature on the surface of the bone, the fourth trochanter, that is prominent and positioned relatively close to the hip, which is a combination of traits known only in some theropods among dinosaurs.
“This fossil won’t win a beauty contest,” lead author Dr. Sidor said. “But fortunately it preserves enough anatomy that we were able compare it to other dinosaurs and be confident of its identification.” “The fossil record of the West Coast is very spotty when compared to the rich record of the interior of North America,” said Peecook. “This specimen, though fragmentary, gives us insight into what the West Coast was like 80 million years ago, plus it gets Washington into the dinosaur club!”
Because the fossil is incomplete, paleontologists aren’t able to identify the exact family or species it belonged to. However, Drs. Sidor and Peecook compared the fossil to other specimens and were able to calculate and estimate that the complete femur would have been over a meter in length (1.17m)–slightly smaller than T. rex.
Fossilized prehistoric clams were also found inside the hollow part of the bone, which indicates the dinosaur fossilized in marine rock. These additional fossils are a rare occurrence, and provide scientists with a snapshot of other lifeforms that were present where the dinosaur fossilized. The accompanying fossilized clams are so well-preserved that Burke paleontologists were able to identify the clam species, Crassatellites conradiana. These clams lived in shallow water, so the authors suggest that it’s likely the dinosaur died near the sea, was tossed by the waves, and eventually came to rest among the clams.
Welcome to Archaeo-Chat. In this series we record unscripted conversations about archaeology, what it is like to be an archaeologist and related topics.
Today, Aaron and I discuss proposed legislation in Wales which could see a step-change in the way ancient monuments are cared for. We also examine the aftermath of the earthquakes in Nepal and their effect on ancient sites and monuments.
Historic Environment (Wales) Bill:
The Historic Environment Bill: what does it do?
UNESCO OFFICE IN KATHMANDU:
UNESCO Press Release:
Zooarchaeology is a discipline that studies the relationship between human beings and animals throughout history.
To do this, zooarchaelogists study the remains of animals found in archaeological sites. This discipline studies questions relating to livestock husbandry, food or the ritual use of animals, among other things.
The paper ‘Livestock management in Spain from Roman to post-medieval times: a biometrical analysis of cattle, sheep/goat and pig’ is the outcome of the PhD research work conducted by Idoia Grau-Sologestoa and completed in 2014 at the UPV/EHU, and has been published recently in the prestigious Journal of Archaeological Science which specialises in archaeology.
It is an analysis of metric data taken from the remains of domestic animals (cows, sheep and pigs) salvaged on archaeological sites across the Iberian Peninsula. The measurements analysed (numbering over 2,500) come from 41 archaeological sites dating between the Roman era and today, since the 1st century BCE until the 21st century. Many of these sites are located in the Basque Country, but also in Aragón, Castilla y León, Catalonia, Madrid, Murcia, Navarre, Valencia and the south of Portugal.
The study shows successive changes in the size of domestic animals over time relating to changes in the landscape and production systems. “The increase in animal size is normally linked to improvements of an environmental type (for example to new ways of feeding) or of a genetic type (for example, by importing larger animals). Larger domestic animal size entails a number of economic advantages with an increase in meat production or traction strength. What is more, improved domestic animals tend to grow faster which helps to increase their productivity,” explained Idoia Grau.
Changes during the Roman Empire
In Roman times there was a special interest in improving cattle possibly in connection with the deforestation and agricultural intensification practices which the Roman Empire brought with it. During the first centuries after the fall of the Empire, domestic animal size did not undergo significant changes. “It is possible that zootechnical knowledge of the Roman era may not have been lost suddenly and that the improved Roman livestock was maintained over various generations,” pointed out the researcher.
Nevertheless, between the 8th and the 9th centuries CE domestic animal size reached a minimum in the whole period covered by this study. This size reduction could be linked to the spread of semi-free foraging practices of cattle during the Early Middle Ages, a trend seen elsewhere in Europe and which has been confirmed by the analysis of stable isotopes; this work was carried out by the research group which Idoia Grau belongs to and was published a few months ago in Quaternary International.
After the High Middle Ages, but more clearly since the Late Middle Ages, the size of domestic animals has been increasing progressively, especially that of sheep. It is probable that “this increase is linked to the importance of sheep husbandry in this period not only for meat production but also to take advantage of the wool and milk of these animals,” explained Grau.
But it is in the modern era that animal size reached its maximum. In any case this could be the least-known period from the archaeological point of view, as hardly any analysis has been conducted on groups of fauna remains dated after the 16th century. The research project that Idoia Grau-Sologestoa is currently working on thanks to a post-doctoral grant from the Government of the Basque Autonomous Community (region) at the UPV/EHU and at the University of Sheffield in the United Kingdom is in fact seeking to conduct research into the changes that took place in livestock management during the transition between the Middle Ages and the Modern Era.
Seeps from which gas and oil escape were formative to many ancient cultures and societies. They gave rise to legends surrounding the Delphi Oracle, Chimaera fires and “eternal flames” that were central to ancient religious practices – from Indonesia and Iran to Italy and Azerbaijan. Modern geologists and oil and gas explorers can learn much by delving into the geomythological stories about the religious and social practices of the Ancient World, writes Giuseppe Etiope of the National Institute of Geophysics and Volcanology in Italy. His research is published in the new Springer book Natural Gas Seepage.
“Knowing present-day gas fluxes from a seep and knowing that a seep was active and vigorous two thousand years ago, we can estimate the total amount of gas that has been released to the atmosphere thus far. What can be measured today is probably also valid, at least in terms of orders of magnitude, for the past,” writes Etiope. “Such information may not only be relevant for atmospheric methane budget studies but may also be important for understanding the leaking potential of petroleum systems, whether they are commercial or not.”
Gas-oil seeps have been the source of mythological tales, and many a Biblical and historic event. The observations of ancient naturalists and historians such as Pliny the Elder, who lived two millennia ago, helped to chronicle many of these occurrences, especially in the Mediterranean area. For example, he wrote about Chimaera, a large burning gas seep in modern day Turkey.. In ancient times, the temple of Hephaestus, the Greek god of fire, was built next to it.
Similar “eternal fires” integrated gas and flame emissions into ancient religious practices in many cultures. For instance, the Zoroastrians worshiped the “Pillars of Fire” near modern Baku in Azerbaijan. In Iraq, the Baba Gurgur seep was probably the “burning fiery furnace” into which King Nebuchadnezzar cast the Jews. A legend of ancient Rome reports a stream of crude oil issuing from the ground around 38 BC. It became a meeting spot for the first Roman converts to Christianity, and is now the site for the Basilica of Santa Maria in Trastevere. The sacred Manggarmas flame in Indonesia, which has been active at least since the 15th century, is still used in an annual Buddhist ceremony.
“Knowing that a certain ‘eternal fire’ observed today was already active in Biblical times indicates that it was not triggered by the recent drilling and production of petroleum,” adds Etiope.
Etiope writes that hydrocarbon seeps also influenced the social and technological development of many ancient populations. It not only contributed to global civilization, but was often the source of wars. The first evidence for petroleum usage comes from Syria, where the Neanderthal used natural bitumen on stone tools some 40,000 years ago.
The discovery is reported in the early edition of Proceedings of the National Academy of Sciences the week of May 18. It sheds light, researchers say, on a monumental change that has left modern humans susceptible to osteoporosis, a condition marked by brittle and thinning bones.
At the root of the finding, the researchers say, is the knowledge that putting bones under the “stress” of walking, lifting and running leads them to pack on more calcium and grow stronger.
“There was a lot of evidence that earlier humans had stronger bones and that weight-bearing exercise in modern humans prevents bone loss, but we didn’t know whether the shift to weaker bones over the past 30,000 years or so was driven by the rise in agriculture, diet, urbanization, domestication of the horse or other lifestyle changes,” says Christopher Ruff, Ph.D. , a professor of functional anatomy and evolution at the Johns Hopkins University School of Medicine.
“By analyzing many arm and leg bone samples from throughout that time span, we found that European humans’ bones grew weaker gradually as they developed and adopted agriculture and settled down to a more sedentary lifestyle, and that moving into cities and other factors had little impact.”
The study was a collaborative effort of researchers from across Europe and the United States that began in 2008. The group focused on Europe because it has many well-studied archeological sites, Ruff says, and because the population has relatively little genetic variation, despite some population movements. That meant that any changes observed could be attributed more to lifestyle than to genetics.
For the study, the researchers took molds of bones from museums’ collections and used a portable X-ray machine to scan them, focusing on two major bones from the legs and one from the arms. “By comparing the lower limbs with the upper limbs, which are little affected by how much walking or running a person does, we could determine whether the changes we saw were due to mobility or to something else, like nutrition,” Ruff says.
When they analyzed the geometry of bones over time, the researchers found a decline in leg bone strength between the Mesolithic era, which began about 10,000 years ago, and the age of the Roman Empire, which began about 2,500 years ago. Arm bone strength, however, remained fairly steady. “The decline continued for thousands of years, suggesting that people had a very long transition from the start of agriculture to a completely settled lifestyle,” Ruff says. “But by the medieval period, bones were about the same strength as they are today.”
Ruff notes that Paleolithic-style bones are still likely achievable, at least for younger humans, if they recreate to some extent the lifestyle of their ancestors, notably doing a lot more walking than their peers. He cites studies of professional athletes that have demonstrated how lifestyle is written in our bones. “The difference in bone strength between a professional tennis player’s arms is about the same as that between us and Paleolithic humans,” he says.
Welcome to In Focus. In this series we take a closer look at particular sites, finds and objects from the world of Archaeology.
*News* Ötzi’s Genome Analysed:
The results, published today (7 May) in the journal Current Biology, identify a key point in the evolutionary transition from soft to hard bodies in early ancestors of arthropods, the group that contains modern insects, crustaceans and spiders.
The study looked at two types of arthropod ancestors – a soft-bodied trilobite and a bizarre creature resembling a submarine. It found that a hard plate, called the anterior sclerite, and eye-like features at the front of their bodies were connected through nerve traces originating from the front part of the brain, which corresponds with how vision is controlled in modern arthropods.
The new results also allowed new comparisons with anomalocaridids, a group of large swimming predators of the period, and found key similarities between the anterior sclerite and a plate on the top of the anomalocaridid head, suggesting that they had a common origin. Although it is widely agreed that anomalocaridids are early arthropod ancestors, their bodies are actually quite different. Thanks to the preserved brains in these fossils, it is now possible to recognise the anterior sclerite as a bridge between the head of anomalocaridids and that of more familiar jointed arthropods.
“The anterior sclerite has been lost in modern arthropods, as it most likely fused with other parts of the head during the evolutionary history of the group,” said Dr Javier Ortega-Hernández, a postdoctoral researcher from Cambridge’s Department of Earth Sciences, who authored the study. “What we’re seeing in these fossils is one of the major transitional steps between soft-bodied worm-like creatures and arthropods with hard exoskeletons and jointed limbs – this is a period of crucial transformation.”
Ortega-Hernández observed that bright spots at the front of the bodies, which are in fact simple photoreceptors, are embedded into the anterior sclerite. The photoreceptors are connected to the front part of the fossilised brain, very much like the arrangement in modern arthropods. In all likelihood these ancient brains processed information like in today’s arthropods, and were crucial for interacting with the environment, detecting food, and escaping from predators.
During the Cambrian Explosion, a period of rapid evolutionary innovation about 500 million years ago when most major animal groups emerge in the fossil record, arthropods with hard exoskeletons and jointed limbs first started to appear. Prior to this period, most animal life on Earth consisted of enigmatic soft-bodied creatures that resembled algae or jellyfish.
These fossils, from the collections of the Royal Ontario Museum in Toronto and the Smithsonian Institution in Washington DC, originated from the Burgess Shale in Western Canada, one of the world’s richest source of fossils from the period.
Since brains and other soft tissues are essentially made of fatty-like substances, finding them as fossils is extremely rare, which makes understanding their evolutionary history difficult. Even in the Burgess Shale, one of the rare places on Earth where conditions are just right to enable exceptionally good preservation of Cambrian fossils, finding fossilised brain tissue is very uncommon. In fact, this is the most complete brain found in a fossil from the Burgess Shale, as earlier results have been less conclusive.
“Heads have become more complex over time,” said Ortega-Hernández, who is a Fellow of Emmanuel College. “But what we’re seeing here is an answer to the question of how arthropods changed their bodies from soft to hard. It gives us an improved understanding of the origins and complex evolutionary history of this highly successful group.”
Did ocean acidification from the asteroid impact that killed the dinosaurs cause the extinction of marine molluscs?
Ammonites, which were free-swimming molluscs of the ancient oceans and are common fossils, went extinct at the time of the end-Cretaceous asteroid impact, as did more than 90 per cent of species of calcium carbonate-shelled plankton (coccolithophores and foraminifera).
Comparable groups not possessing calcium carbonate shells were less severely affected, raising the possibility that ocean acidification, as a side-effect of the collision, might have been responsible for the apparent selectivity of the extinctions.
Previous CO2 rises on Earth happened so slowly that the accompanying ocean acidification was relatively minor, and ammonites and other planktonic calcifiers were able to cope with the changing ocean chemistry. The asteroid impact, in contrast, caused very sudden changes.
In the first modelling study of ocean acidification which followed the asteroid impact, the researchers simulated several acidifying mechanisms, including wildfires emitting CO2 into the atmosphere (as carbon dioxide emissions dissolve in seawater they lower the pH of the oceans making them more acidic and more corrosive to shells) and vaporisation of gypsum rocks leading to sulphuric acid or ‘acid rain’ being deposited on the ocean surface.
The researchers concluded that the acidification levels produced were too weak to have caused the disappearance of the calcifying organisms.
Professor Toby Tyrrell, from Ocean and Earth Science at the University of Southampton and co-author of the study, says:
“While the consequences of the various impact mechanisms could have made the surface ocean more acidic, our results do not point to enough ocean acidification to cause global extinctions. Out of several factors we considered in our model simulation, only one (sulphuric acid) could have made the surface ocean severely corrosive to calcite, but even then the amounts of sulphur required are unfeasibly large.
“It throws up the question, if it wasn’t ocean acidification what was it? Possible alternative extinction mechanisms, such as intense and prolonged darkness from soot and aerosols injected into the atmosphere, should continue to be investigated.”
The study, which is published in the Proceedings of the National Academy of Sciences (PNAS), involved researchers from the University of Southampton and the Leibniz Center for Tropical Marine Ecology. The project received funding from the European Project on Ocean Acidification and funding support from NERC, Defra and DECC to the UK Ocean Acidification programme (grant no. NE/H017348/1).
The team, led by the University of Leiden, and including researchers from Historic England and the universities of Southampton, Birmingham, Surrey, and Swansea, examined a 1500 year old male skeleton, excavated at Great Chesterford in Essex, England during the 1950s.
The bones of the man, probably in his 20s, show changes consistent with leprosy, such as narrowing of the toe bones and damage to the joints, suggesting a very early British case. Modern scientific techniques applied by the researchers have now confirmed the man did suffer from the disease and that he may have come from southern Scandinavia.
Archaeologist Dr Sonia Zakrzewski, of the University of Southampton, explains DNA testing was necessary to get a clear diagnosis: “Not all cases of leprosy can be identified by changes to the skeleton. Some may leave no trace on the bones; others will affect bones in a similar way to other diseases. In these cases the only way to be sure is to use DNA fingerprinting, or other chemical markers characteristic of the leprosy bacillus.”
The researchers tested the skeleton for bacterial DNA and lipid biomarkers to confirm the man had definitely had leprosy and to allow them to carry out a detailed genetic study of the bacteria that caused his illness.
Professor Mike Taylor, a Bioarchaeologist from the University of Surrey, says: “Not every excavation yields good quality DNA, but in this case, leprosy DNA isolated from the skeleton was so good it enabled us to identify its strain.”
The results showed the leprosy strain belonged to a lineage (3I) which has previously been found in burials from Medieval Scandinavia and southern Britain, but in this case it originates from a much earlier period, dating from the 5th or 6th centuries AD.
The identification of fatty molecules (lipids) from the leprosy bacteria confirmed the DNA results and also showed it was different from later strains. Emeritus scientist David Minnikin, from the University of Birmingham, says: “With Leverhulme Trust support, we recorded strong profiles of fatty acid lipid biomarkers that confirmed the presence of leprosy. However, one class of the lipid biomarkers had distinct profiles that may distinguish these older leprosy cases from later Medieval examples.”
Isotopes from the man’s teeth showed that he probably did not come from Britain, but more likely grew up elsewhere in northern Europe, perhaps southern Scandinavia. This matched the results of the DNA, and raises the intriguing possibility that he brought a Scandinavian strain of the leprosy bacterium with him when he migrated to Britain.
Project leader Dr Sarah Inskip of Leiden University concludes: “The radiocarbon date confirms this is one of the earliest cases in the UK to have been successfully studied with modern biomolecular methods. This is exciting both for archaeologists and for microbiologists. It helps us understand the spread of disease in the past, and also the evolution of different strains of disease, which might help us fight them in the future. We plan to carry out similar studies on skeletons from different locations to build up a more complete picture of the origins and early spread of this disease.”
Although leprosy is nowadays a tropical disease, in the past it occurred in Europe. Human migrations probably helped spread it, and there are cases in early skeletons from western Europe, particularly from the 7th century AD onward. However the origins of these ancient cases are poorly understood. The study of the Great Chesterford skeleton provided an important opportunity to shed light on the early spread of leprosy.
The results of the study will be published in the journal PLOS ONE and copies of the paper can be requested from Media Relations.
Welcome to Archaeoscoop. In this series we bring you breaking news, headlines and interviews from the archaeological world.
Child’s 2,000-year-old sock goes on display:
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