Thursday, March 24, 2011

Earliest American residents came at least 15,500 years ago

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New discoveries at a Central Texas archaeological site by a Texas A&M University-led research team prove that people lived in the region far earlier – as much as 2,500 years earlier – than previously believed, rewriting what anthropologists know about when the first inhabitants arrived in North America. That pushes the arrival date back to about 15,500 years ago.

Michael Waters, director of Texas A&M's Center for the Study of First Americans, along with researchers from Baylor University, the University of Illinois-Chicago, the University of Minnesota, and Texas State University, have found the oldest archaeological evidence for human occupation in Texas and North America at the Debra L.Friedkin site, located about 40 miles northwest of Austin. Their work is published in the current issue of Science magazine.

Waters says that buried in deposits next to a small spring-fed stream is a record of human occupation spanning the last 15,500 years. Near the surface is the record of the Late Prehistoric and Archaic occupants of the region. Buried deeper in the soil are layers with Folsom and Clovis occupations going back 12,000 to 13,000 years ago.

"But the kicker was the discovery of nearly 16,000 artifacts below the Clovis horizon that dated to 15,500 years ago," Waters notes.

"Most of these are chipping debris from the making and resharpening of tools, but over 50 are tools. There are bifacial artifacts that tell us they were making projectile points and knives at the site," Waters says. There are expediently made tools and blades that were used for cutting and scraping."

Multiple studies have shown that the site is undisturbed and that the artifacts are in place and over 60 "luminescence dates" show that early people arrived at the site by 15,500 years ago, Waters explains. Luminescence dating technique is a method used to date the sediment surrounding the artifacts. It dates the last time the sediment was exposed to sunlight.

For more than 80 years, it has been argued that the Clovis people were the first to enter the Americas, Waters says. He goes on to say that over the last few decades, there have been several credible sites which date older than Clovis found in North America -- specifically in Wisconsin, Pennsylvania, Florida, and Oregon.

"However, this evidence is not very robust," Waters observes.

"What is special about the Debra L. Friedkin site is that it has the largest number of artifacts dating to the pre-Clovis time period, that these artifacts show an array of different technologies, and that these artifacts date to a very early time.

"This discovery challenges us to re-think the early colonization of the Americas. There's no doubt these tools and weapons are human-made and they date to about 15,500 years ago, making them the oldest artifacts found both in Texas and North America."

Waters has been working at the site since 2006, and analysis of the artifacts collected from the site is ongoing. Waters says, "These studies will help us figure out where these people came from, how they adapted to the new environments they encountered, and understand the origins of later groups like Clovis

The Clovis people, whose tools were known for their distinctive "fluted" points, were once thought to be the original settlers of North America about 13,000 years ago. Over the past few years, however, scattered evidence has hinted at several earlier cultures. But, such evidence has often been disputed in part because so few artifacts have actually been recovered.




These are some of the artifacts from the 15,500-year-old horizon.

The newly discovered tools are small and made of chert, and the researchers suggest that they were designed for a mobile toolkit—something that could be easily packed up and moved to a new location. These tools are recognizably different from Clovis tools although they do share some similarities, including the use of biface and bladelet technology.

UIC earth and environmental sciences professor Steven Forman worked with Waters and a multi-university team of researchers, finding buried beneath the Clovis layer tools such as blades and cores -- technologies unique to the Clovis culture.

Forman gathered about 50 core samples from two sites at Buttermilk Creek for luminescence dating analysis at UIC. Carbon-14 dating couldn't be used to date the pre-Clovis artifact layer because that layer didn't contain any organic matter.

"We dated the sediments by a variety of optical methods," Forman said. "We also dated different mineral fractions as well, and we consistently got the same ages. We looked at the age structure of the sediment by many different ways and got the same answers."

This is the first time that optical dating has been used to constrain a paleoculture within a date range, Forman said.

Luminescence dating, a relatively new technique, measures light energy trapped in minerals such as feldspar and quartz formed centuries ago. Samples must be carefully handled to avoid any exposure to light, which would contaminate the readings. They were analyzed in a darkroom laboratory at UIC.

In the past, researchers have argued that the Clovis people were the oldest human inhabitants of the Americas. This "Clovis First" model theorizes that the Clovis people came to the New World from Northeast Asia by crossing the Bering Land Bridge, which once connected Asia and North America. From there, it suggests that they spread out across the continent and eventually made their way down to South America.

However, some problems with this model have recently arisen. First of all, no Clovis technology has been found in Northeast Asia and the fluted points that have been discovered in Alaska are all too young to be Clovis. (They were also made a bit differently than Clovis points.) Furthermore, there are six sites in South America that do not contain Clovis technology, although they did exist during the same time period.

The Debra L. Friedkin site in Texas, implies that Clovis tools could have eventually evolved from the tools found in the Buttermilk Creek Complex—and that the Clovis culture, including the use of fluted points, likely developed in North America.

"This discovery provides ample time for Clovis to develop," said Waters. "People [from the Buttermilk Creek Complex] could have experimented with stone and invented the weapons and tools that we now recognize as Clovis… In short, it is now time to abandon once and for all the 'Clovis First' model and develop a new model for the peopling of the Americas."

Monday, March 14, 2011

Continuous control of fire by Neanderthals

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A new study involving the University of Colorado Boulder shows clear evidence of the continuous control of fire by Neanderthals in Europe dating back roughly 400,000 years, yet another indication that they weren't dimwitted brutes as often portrayed.

The conclusion comes from the study of scores of ancient archaeological research sites in Europe that show convincing evidence of long-term fire control by Neanderthals, said Paola Villa, a curator at the University of Colorado Museum of Natural History. Villa co-authored a paper on the new study with Professor Wil Roebroeks of Leiden University in the Netherlands.

"Until now, many scientists have thought Neanderthals had some fires but did not have continuous use of fire," said Villa. "We were not expecting to find a record of so many Neanderthal sites exhibiting such good evidence of the sustained use of fire over time."

A paper on the subject was published in the March 14 issue of the Proceedings of the National Academy of Sciences.

Neanderthals are thought to have evolved in Europe roughly 400,000 to 500,000 years ago and went extinct about 30,000 years ago. Neanderthals ranged over much of Europe and stretched to Central Asia. Neanderthals were stockier than anatomically modern humans and even shared the same terrain for a time, and there is evidence that contemporary humans carry a small amount of Neanderthal DNA. Modern humans began migrating out of Africa to Europe some 40,000 years ago.

Archaeologists consider the emergence of stone tool manufacturing and the control of fire as the two hallmark events in the technological evolution of early humans. While experts agree the origins of stone tools date back at least 2.5 million years in Africa, the origin of fire control has been a prolonged and heated debate.

Villa and Roebroeks, who together speak and read six languages, have visited or worked at dozens of the Neanderthal excavation sites in Europe. They also combed libraries throughout Europe and the United States for research papers on evidence for early fire use in Europe, contacting researchers involved in the excavations when possible for additional information and insight.

As part of the study they created a database of 141 potential fireplace sites in Europe dating from 1.2 million years ago to 35,000 years ago, assigning an index of confidence to each site. Evidence for the sustained use of fire includes the presence of charcoal, heated stone artifacts, burned bones, heated sediments, hearths and rough dates obtained from heated stone artifacts. Sites with two or more of the characteristics were interpreted as solid evidence for the control of fire by the inhabitants.

The second major finding in the PNAS study -- perhaps even more surprising than the first -- was that Neanderthal predecessors pushed into Europe's colder northern latitudes more than 800,000 years ago without the habitual control of fire, said Roebroecks. Archaeologists have long believed the control of fire was necessary for migrating early humans as a way to reduce their energy loss during winters when temperatures plunged below freezing and resources became more scarce.

"This confirms a suspicion we had that went against the opinions of most scientists, who believed it was impossible for humans to penetrate into cold, temperate regions without fire," Villa said.

Recent evidence from an 800,000-year-old site in England known as Happisburgh indicates hominids -- likely Homo heidelbergenis, the forerunner of Neanderthals -- adapted to chilly environments in the region without fire, Roebroeks said.

The simplest explanation is that there was no habitual use of fire by early humans prior to roughly 400,000 years ago, indicating that fire was not an essential component of the behavior of the first occupants of Europe's northern latitudes, said Roebroeks. "It is difficult to imagine these people occupying very cold climates without fire, yet this seems to be the case."

While the oldest traces of human presence in Europe date to more than 1 million years ago, the earliest evidence of habitual Neanderthal fire use comes from the Beeches Pit site in England dating to roughly 400,000 years ago, said Villa. The site contained scattered pieces of heated flint, evidence of burned bones at high temperatures, and individual pockets of previously heated sediments. Neanderthals, like other early humans, created and used a unique potpourri of stone tools, evidence that they were the ancient inhabitants of particular sites in Europe.

The sites catalogued by the team were dated by several methods, including electron spin resonance, paleomagnetism and thermoluminescence. Some research teams also have used microscopic studies of sediment at sites to confirm the presence of ashes. While some of the best evidence for controlled use of fire in Europe comes from caves, there are many open-air sites with solid evidence of controlled fire, they said.

According to Villa, one of the most spectacular uses of fire by Neanderthals was in the production of a sticky liquid called pitch from the bark of birch trees that was used by Neanderthals to haft, or fit wooden shafts on, stone tools. Since the only way to create pitch from the trees is to burn bark peels in the absence of air, archaeologists surmise Neanderthals dug holes in the ground, inserted birch bark peels, lit them and covered the hole tightly with stones to block incoming air.

"This means Neanderthals were not only able to use naturally occurring adhesive gums as part of their daily lives, they were actually able to manufacture their own," Villa said. "For those who say Neanderthals did not have elevated mental capacities, I think this is good evidence to the contrary."

Many archaeologists believe Neanderthals and other early hominids struck pieces of flint with chunks of iron pyrite to create the sparks that made fire and may well have conserved and transported fire from site to site.

Some anthropologists have proposed that Neanderthals became extinct because their cognitive abilities were inferior, including a lack of long-term planning, said Villa. But the archaeological record shows Neanderthals drove herds of big game animals into dead-end ravines and ambushed them, as evidenced by repeatedly used kill sites -- a sign of long-term planning and coordination among hunters, she said.

Recent findings have even indicated Neanderthals were cooking, as evidenced by tiny bits of cooked plant material recovered from their teeth.

Wednesday, March 9, 2011

Finding the Lost City of Atlantis

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Could the fabled lost city of Atlantis have been located? Using satellite photography, ground-penetrating radar and underwater technology, a team of experts (led by University of Hartford professor and archaeologist Richard Freund) has been surveying marshlands in Spain to look for proof of the ancient city. If the team can match geological formations to Plato’s descriptions and date artifacts back to the time of Atlantis, we may be closer to solving one of the world's greatest mysteries.

A new National Geographic Channel documentary, Finding Atlantis, which will be broadcast nationally on Sunday, March 13, at 9 p.m. ET/PT, follows a team of American, Canadian, and Spanish scientists as they employ satellite space photography, ground penetrating radar, underwater archaeology, and historical sleuthing in an effort to find a lost civilization. The University of Hartford’s Greenberg Center for Judaic Studies, of which Freund is the director, will be hosting an advance screening of Finding Atlantis on Wednesday, March 9, at 7 p.m., in the University’s Wilde Auditorium.

When a space satellite photograph identified what looked like a submerged city in the midst of one of the largest swamps in Europe, the Doña Ana Park in southern Spain, Freund was contacted to see if he could assemble his team to apply their cutting-edge technology (electrical resistivity tomography, which is a virtual MRI for the ground, ground penetrating radar, and digital mapping that quickly and efficiently maps the subsurface of a site and provides instantaneous results for excavators to follow) to this project. In 2009 and 2010, they worked with Spanish archaeologists and geologists to explore the remains of an ancient city that goes back some 4,000 years.

However, the ultimate solution to what happened to Atlantis was not resolved in the south of Spain but in Freund’s discovery of a series of mysterious memorial cities built in the image of Atlantis in central Spain. Following Freund and his team, headed by geophysicist Paul Bauman from WorleyParsons in Calgary, Canada and geographer Philip Reeder from the University of South Florida, the documentary tracks the search for one of the great cultural icons of all time: Atlantis.

The lost city of Atlantis is one of the world’s most famous mysteries. According to Plato who wrote about it almost 2,600 years ago, Atlantis was “an island situated in front of the straits which are by you called the Pillars of Hercules” (The Straits of Gibraltar were known as the Pillars of Hercules in antiquity.), Using Plato’s detailed account of the mysterious city as a map, Finding Atlantis searches the Mediterranean and Atlantic for the best possible location for Atlantis.

The film journeys to Turkey and the Greek islands of Crete and Santorini before heading to southern Spain, beyond the Pillars of Hercules. Plato says that Atlantis once faced a city called “Gadara,” which is the ancient name for modern Cadiz. Here, catamarans and dive boats take the viewer deep into the ocean off the coast of Spain, as a crack team of marine archaeologists and geologists employ sonar and scuba in search of sub-surface man-made structures dating back to the Bronze Age.

And in the vast mudflats of the Guadalquivir river delta, scientists examine strange geometric shadows of what look to be the remains of a ringed city. Here, geophysicists and archaeologists employ the most advanced imaging technologies in the world to determine whether or not an ancient cataclysm suddenly buried a thriving civilization under meters and meters of ocean and mud.

Finally, Finding Atlantis presents the viewer with what is quite possibly the most intriguing piece of archaeology ever associated with Atlantis. Recently discovered 2,800-year-old ruins display an image carved in stone of what looks to be an Atlantean warrior – guarding the entrance to the lost, multi-ringed city!

Saturday, March 5, 2011

California Islands Give Up Evidence of Early Seafaring:

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Numerous Artifacts Found at Late Pleistocene Sites on the Channel Islands


Evidence for a diversified sea-based economy among North American inhabitants dating from 12,200 to 11,400 years ago is emerging from three sites on California's Channel Islands.

Reporting in the March 4 issue of Science, a 15-member team led by University of Oregon and Smithsonian Institution scholars describes the discovery of scores of stemmed projectile points and crescents dating to that time period. The artifacts are associated with the remains of shellfish, seals, geese, cormorants and fish.

Funded primarily by grants from the National Science Foundation, the team also found thousands of artifacts made from chert, a flint-like rock used to make projectile points and other stone tools.

Some of the intact projectiles are so delicate that their only practical use would have been for hunting on the water, said Jon Erlandson, professor of anthropology and director of the Museum of Natural and Cultural History at the University of Oregon. He has been conducting research on the islands for more than 30 years.

"This is among the earliest evidence of seafaring and maritime adaptations in the Americas, and another extension of the diversity of Paleoindian economies," Erlandson said. "The points we are finding are extraordinary, the workmanship amazing. They are ultra thin, serrated and have incredible barbs on them. It's a very sophisticated chipped-stone technology." He also noted that the stemmed points are much different than the iconic fluted points left throughout North America by Clovis and Folsom peoples who hunted big game on land.

The artifacts were recovered from three sites that date to the end of the Pleistocene epoch on Santa Rosa and San Miguel islands, which in those days were connected as one island off the California coast. Sea levels then were 50 to 60 meters (about 160-200 feet) below modern levels. Rising seas have since flooded the shorelines and coastal lowlands where early populations would have spent most of their time.

Erlandson and his colleagues have focused their search on upland features such as springs, caves, and chert outcrops that would have drawn early maritime peoples into the interior. Rising seas also may have submerged evidence of even older human habitation of the islands.

The newly released study focuses on the artifacts and animal remains recovered, but the implications for understanding the peopling of the Americas may run deeper.

The technologies involved suggest that these early islanders were not members of the land-based Clovis culture, Erlandson said. No fluted points have been found on the islands. Instead, the points and crescents are similar to artifacts found in the Great Basin and Columbia Plateau areas, including pre-Clovis levels at Paisley Caves in eastern Oregon that are being studied by another UO archaeologist, Dennis Jenkins.

Last year, Charlotte Beck and Tom Jones, archaeologists at New York's Hamilton College who study sites in the Great Basin, argued that stemmed and Clovis point technologies were separate, with the stemmed points originating from Pacific Coast populations and not, as conventional wisdom holds, from the Clovis people who moved westward from the Great Plains. Erlandson and colleagues noted that the Channel Island points are also broadly similar to stemmed points found early sites around the Pacific Rim, from Japan to South America.

Six years ago, Erlandson proposed that Late Pleistocene sea-going people may have followed a "kelp highway" stretching from Japan to Kamchatka, along the south coast of Beringia and Alaska, then southward down the Northwest Coast to California. Kelp forests are rich in seals, sea otters, fish, seabirds, and shellfish such as abalones and sea urchins.

"The technology and seafaring implications of what we've found on the Channel Islands are magnificent," said study co-author Torben C. Rick, curator of North American Archaeology at the Smithsonian Institution. "Some of the paleo-ecological and subsistence implications are also very important. These sites indicate very early and distinct coastal and island subsistence strategies, including harvest of red abalones and other shellfish and fish dependent on kelp forests, but also the exploitation of larger pinnipeds and waterfowl, including an extinct flightless duck.

"This combination of unique hunting technologies found with marine mammal and migratory waterfowl bones provides a very different picture of the Channel Islands than what we know today, and indicates very early and diverse maritime life ways and foraging practices," Rick said. "What is so interesting is that not only do the data we have document some of the earliest marine mammal and bird exploitation in North America, but they show that very early on New World coastal peoples were hunting such animals and birds with sophisticated technologies that appear to have been refined for life in coastal and aquatic habitats."

The stemmed points found on the Channel Islands range from tiny to large, probably indicating that they were used for hunting a variety of animals.

"We think the crescents were used as transverse projectile points, probably for hunting birds. Their broad stone tips, when attached to a dart shaft provided a stone age shotgun-approach to hunting birds in flight," Erlandson said. "These are very distinctive artifacts, hundreds of which have been found on the Channel Islands over the years, but rarely in a stratified context, he added. Often considered to be between 8,000 and 10,000 years old in California, "we now have crescents between 11,000 and 12,000 years old, some of them associated with thousands of bird bones."

The next challenge, Erlandson and Rick noted, is to find even older archaeological sites on the Channel Islands, which might prove that a coastal migration contributed to the initial peopling of the Americas, now thought to have occurred two to three millennia earlier.