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M3GA V 7.1 :: CHANNEL 11 :: Outersphere :: Digging In The Dirt V
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Re: Digging In The Dirt V
« Reply #60 on Dec 5, 2011, 11:08pm »
6 December 2011 Last updated at 01:38 GMT

Cores reveal when Dead Sea 'died'
By Jonathan Amos Science correspondent, BBC News, San Francisco

[image]
Aragonite and gypsum deposits at the edge of the Dead Sea record the region's climate history

Sediments drilled from beneath the Dead Sea reveal that this most remarkable of water bodies all but disappeared 120,000 years ago.

It is a discovery of high concern say scientists because it demonstrates just how dry the Middle East can become during Earth's warm phases.

In such ancient times, few if any humans were living around the Dead Sea.

Today, its feed waters are intercepted by large populations and the lake level is declining rapidly.

"The reason the Dead Sea is going down is because virtually all of the fresh water flowing into it is being taken by the countries around it," said Steve Goldstein, a geochemist at Columbia University's Lamont-Doherty Earth Observatory, US.

"But we now know that in a previous warm period, the water that people are using today and are relying upon stopped flowing all by itself. That has important implications for people today because global climate models are predicting that this region in particular is going to become more arid in the future," he told BBC News.

Prof Goldstein has been presenting the results of the drilling work here at the 2011 American Geophysical Union (AGU) Fall Meeting, the largest annual gathering of Earth scientists.

The Dead Sea is an extraordinary place. The surface of the inland waterway sits at the lowest land point on the planet, more than 400m below sea level.

[image]

Its hyper-salty waters descend in places a further 300m. And below the lake bed is layer upon layer of sediments that record the Dead Sea's history and the climate conditions that have prevailed in the region over hundreds of thousands of years.

A consortium of investigators from Israel, the US, Germany, Japan, Switzerland and Norway drilled two cores into the Dead Sea's bed in late 2010. One of them was centred close to the very deepest part of the lake.

At 235m down, the consortium hit a layer of small, rounded pebbles - what the team believes are the deposits of an ancient beach. Given the location of the core, this would suggest the Dead Sea had a complete, or near, dry-down at some point in the past.

Formal dating of the core sediments has not yet been completed, but their pattern leads the team to conclude that the dry-down occurred in the Eemian. This was a stage in Earth history when global temperatures were as warm, if not slightly warmer, than they are today.

The modern day Middle East is preventing water getting into the Dead Sea. The surrounding countries are using it for agriculture. Fertiliser and salt manufacturing are also having an impact. Since 1997, the lake's surface has fallen more than 10m.

"Lake dry-down happened 120,000 years ago without any human intervention," said Prof Emi Ito, from the University of Minnesota, Minneapolis. "We're helping the lake level go down much sooner; and there are political implications of this lake drying down because water is what causes a lot of wars and I'll just leave it at that."

Prof Zvi Ben-Avraham, of the Minerva Dead Sea Research Centre, Tel Aviv University, added: "The drilling actually... it gives us perspective. Look what went on in 200,000 years; look how the area can be dry and look at the way it can be recovered. We have to get ready for the future."

Past research has shown very clearly how the size of the Dead Sea has fluctuated with the coming and going of ice ages.

During the interglacials (warm periods), the lake shrank; and during glacials (cold phases), the lake grew. And it was in the midst of the last ice age some 25,000 years ago that the Dead Sea reached its maximum extent, with the then water surface standing an astonishing 260m above where it is today.

This giant palaeo-lake, referred to by scientists as Lake Lisan, would have inundated the whole Dead Sea valley, even encompassing the Sea of Galilee to the north.

[image]
The core contains rounded pebbles that the team interprets as ancient beach deposit

The consortium has traced these changes in the laminated sediments that line the surrounding cliffs and hills.

It is possible to see exquisite, alternating bands of light (aragonite) and dark (marl) material in the exposed rock.

The light layers are calcium carbonate (aragonite) precipitated out of the water in warm summer months. The dark bands (marl) are winter storm deposits.

But it is also possible to find layers of calcium sulphate (gypsum) and even salt, which relate to extended periods of dry weather when feed waters to the Dead Sea have not kept pace with evaporation.

"All these deposits from the last ice age are sitting at the edge of the lake, and we've been studying them for 20 years," said Prof Goldstein.

"We know a lot about Lake Lisan, but what we didn't know until now was very much about what happened in the warm ages, because in warm ages the lake shrinks and those deposits are under the Dead Sea. That's why we had to go drill them."

[image]
The surface of the Dead Sea is falling by about a metre a year

Jonathan.Amos-INTERNET@bbc.co.uk

http://www.bbc.co.uk/news/science-environment-15938294
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"All truth passes through three stages. First, it is ridiculed, second it is violently opposed, and third, it is accepted as self-evident."

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"In the final analysis, our most basic common link is that we all inhabit this small planet, breathe the same air, and we all cherish our children’s future."

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Re: Digging In The Dirt V
« Reply #61 on Dec 6, 2011, 9:46am »
Early Earth May Have Been Prone to Deep Freezes, Study Finds

[image]
New research suggests that Earth may have been more prone to catastrophic glaciation than previously believed. (Credit: © arska n / Fotolia)

ScienceDaily (Dec. 5, 2011) — Two University of Colorado Boulder researchers who have adapted a three-dimensional, general circulation model of Earth's climate to a time some 2.8 billion years ago when the sun was significantly fainter than present think the planet may have been more prone to catastrophic glaciation than previously believed.

The new 3-D model of the Archean Eon on Earth that lasted from about 3.8 billion years to 2.5 billion years ago, incorporates interactions between the atmosphere, ocean, land, ice and hydrological cycles, said CU-Boulder doctoral student Eric Wolf of the atmospheric and oceanic sciences department. Wolf has been using the new climate model -- which is based on the Community Earth System Model maintained by the National Center for Atmospheric Research in Boulder -- in part to solve the "faint young sun paradox" that occurred several billion years ago when the sun's output was only 70 to 80 percent of that today but when geologic evidence shows the climate was as warm or warmer than now.

In the past, scientists have used several types of one-dimensional climate models -- none of which included clouds or dynamic sea ice -- in an attempt to understand the conditions on early Earth that kept it warm and hospitable for primitive life forms. But the 1-D model most commonly used by scientists fixes Earth's sea ice extent at one specific level through time despite periodic temperature fluctuations on the planet, said Wolf.

"The inclusion of dynamic sea ice makes it harder to keep the early Earth warm in our 3-D model," Wolf said. "Stable, global mean temperatures below 55 degrees Fahrenheit are not possible, as the system will slowly succumb to expanding sea ice and cooling temperatures. As sea ice expands, the planet surface becomes highly reflective and less solar energy is absorbed, temperatures cool, and sea ice continues to expand."

Wolf and CU-Boulder Professor Brian Toon are continuing to search for the heating mechanism that apparently kept Earth warm and habitable back then, as evidenced by liquid oceans and primordial life forms. While their calculations show an atmosphere containing 6 percent carbon dioxide could have done the trick by keeping the mean temperatures at 57 degrees F, geological evidence from ancient soils on early Earth indicate such high concentrations of CO2 were not present at the time.

The CU-Boulder researchers are now looking at cloud composition and formation, the hydrological cycle, movements of continental masses over time and heat transport through Earth's system as other possible modes of keeping early Earth warm enough for liquid water to exist. Wolf gave a presentation on the subject at the annual American Geophysical Union meeting held Dec. 5-9 in San Francisco.

Toon said 1-D models essentially balance the amount of sunshine reaching the atmosphere, clouds, and Earth's terrestrial and aquatic surfaces with the amount of "earthshine" being emitted back into the atmosphere, clouds, and space, primarily in the infrared portion of the electromagnetic spectrum. "The advantage of a 3-D model is that the transport of energy across the planet and changes in all the components of the climate system can be considered in addition to the basic planetary energy balance."

In the new 3-D model, preventing a planet-wide glaciation requires about three times more CO2 than predicted by the 1-D models, said Wolf. For all warm climate scenarios generated by the 3-D model, Earth's mean temperature about 2.8 billion years ago was 5 to 10 degrees F warmer than the 1-D model, given the same abundance of greenhouse gases. "Nonetheless, the 3-D model indicates a roughly 55 degrees F mean temperature was still low enough to trigger a slide by early Earth into a runaway glacial event, causing what some scientists call a 'Snowball Earth,'" said Wolf.

"The ultimate point of this study is to determine what Earth was like around the time that life arose and during the first half of the planet's history," said Toon. "It would have been shrouded by a reddish haze that would have been difficult to see through, and the ocean probably was a greenish color caused by dissolved iron in the oceans. It wasn't a blue planet by any means." By the end of the Archean Eon some 2.5 billion year ago, oxygen levels rose quickly, creating an explosion of new life on the planet, he said.

Testing the new 3-D model has required huge amounts of supercomputer computation time, said Toon, who also is affiliated with CU-Boulder's Laboratory for Atmospheric and Space Physics. A single calculation for the study run on CU-Boulder's powerful new Janus supercomputer can take up to three months.

The CU-Boulder study was funded by a NASA Earth and Space Science Fellowship to Wolf as well as a grant from the NASA Exobiology and Evolutionary Biology Program.

Toon will be presented with AGU's Roger Revelle Medal for innovative work on the effects of aerosols on clouds and climate at the 2011 San Francisco meeting. The Revelle Medal is presented annually to a scientist who has shown outstanding accomplishments or contributions toward the understanding Earth's climate systems.

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The above story is reprinted from materials provided by University of Colorado at Boulder.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

http://www.sciencedaily.com/releases/2011/12/111205140521.htm
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"All truth passes through three stages. First, it is ridiculed, second it is violently opposed, and third, it is accepted as self-evident."

Arthur Schopenhauer, Philosopher, 1788-1860

"In the final analysis, our most basic common link is that we all inhabit this small planet, breathe the same air, and we all cherish our children’s future."

John F. Kennedy
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Re: Digging In The Dirt V
« Reply #62 on Dec 6, 2011, 9:48am »
Rise of Atmospheric Oxygen More Complicated Than Previously Thought

ScienceDaily (Dec. 1, 2011) — The appearance of oxygen in Earth's atmosphere probably did not occur as a single event, but as a long series of starts and stops, according to an international team of researchers who investigated rock cores from the FAR DEEP project.

The Fennoscandia Arctic Russia -- Drilling Early Earth Project -- FAR DEEP -- took place during the summer of 2007 near Murmansk in the northwest region of Russia. The project, part of the International Continental Scientific Drilling Program, drilled a series of shallow, two-inch diameter cores and, by overlapping them, created a record representing stone deposited during the Proterozoic Eon -- 2,500 million to 542 million years ago.

"We've always thought that oxygen came into the atmosphere really quickly during an event," said Lee R. Kump, professor and head of geosciences, Penn State. "We are no longer looking for an event. Now we are looking for when and why oxygen became a stable part of the Earth's atmosphere."

The researchers report in the Dec. 1 issue of Science Express that evaluation of these cores and comparison with cores from Gabon previously analyzed by others, supports the conclusion that the Great Oxidation Event played out over hundreds of millions of years. Oxygen levels gradually crossed the low atmospheric oxygen threshold for pyrite -- an iron sulfur mineral -- oxidation by 2,500 million years ago and the loss of any mass-independently fractionated sulfur by 2,400 million years ago. Then oxygen levels rose at an ever-increasing rate through the Paleoproterozoic, achieving about 1 percent of the present atmospheric level.

"The definition of when an oxygen atmosphere occurred depends on which threshold you are looking for," said Kump. "It could be when pyrite becomes oxidized, when sulfur MIF disappears or when deep crustal oxidation occurs."

When the mass-independent fractionated sulfur disappeared, the air on Earth was still not breathable by animal standards. When red rocks containing iron oxides appeared 2,300 million years ago, the air was still unbreathable.

"At about 1 percent oxygen, the groundwater became strongly oxidized, making it possible for groundwater seeping through rocks to oxidize organic materials," said Kump.

Initially, any oxygen in the atmosphere, produced by the photosynthesis of single-celled organisms, was used up when sulfur, iron and other elements oxidized. When sufficient oxygen accumulated in the atmosphere, it permeated the groundwater and began oxidizing buried organic material, oxidizing carbon to create carbon dioxide.

The cores from the FAR-DEEP project were compared with the Francevillian samples from Gabon using the ratio of carbon isotopes 13 and 12 to see if the evidence for high rates of oxygen accumulation existed worldwide. Both the FAR-DEEP project's cores and the Francevillian cores show large deposits of carbon in the form of fossilized petroleum. Both sets of cores also show similar changes in carbon 13 through time, indicating that the changes in carbon isotopes occurred worldwide and oxygen levels throughout the atmosphere were high.

"Although others have documented huge carbon isotope variations at later times in Earth history associated with stepwise increases in atmospheric oxygen, our results are less equivocal because we have many lines of data all pointing to the same thing," said Kump. "These indications include not only carbon13 isotope profiles in organic mater from two widely separated locations, but also supporting profiles in limestones and no indication that processes occurring since that time have altered the signal."

Working with Kump on this project were Michael A. Arthur, professor of geosciences, Penn State, and Christopher Junium, former graduate student in geosciences, Penn State, now at Syracuse University; Alex Brasier, postdoctoral fellow, and Anthony Fallick, professor of isotope geosciences, Scottish Universities Environmental Research Centre; Victor Melezhik, Aivo Lepland and Alenka E Crne, researchers at the Norwegian Geological Survey; and Genming Luo, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences.

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The above story is reprinted from materials provided by Penn State.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

1. Lee R. Kump, Christopher Junium, Michael A. Arthur, Alex Brasier, Anthony Fallick, Victor Melezhik, Aivo Lepland, Alenka E. Črne, and Genming Luo. Isotopic Evidence for Massive Oxidation of Organic Matter Following the Great Oxidation Event. Science, 1 December 2011 DOI: 10.1126/science.1213999

http://www.sciencedaily.com/releases/2011/12/111201142754.htm
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"All truth passes through three stages. First, it is ridiculed, second it is violently opposed, and third, it is accepted as self-evident."

Arthur Schopenhauer, Philosopher, 1788-1860

"In the final analysis, our most basic common link is that we all inhabit this small planet, breathe the same air, and we all cherish our children’s future."

John F. Kennedy
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Re: Digging In The Dirt V
« Reply #63 on Dec 7, 2011, 8:09am »
Ancient Meat-Loving Predators Survived for 35 Million Years

[image]
Top: Varanodon. Bottom: Aerosaurus. (Credit: Diane Scott)

ScienceDaily (Dec. 6, 2011) — A species of ancient predator with saw-like teeth, sleek bodies and a voracious appetite for meat survived a major extinction at a time when the distant relatives of mammals ruled Earth.

A detailed description of a fossil that scientists identify as a varanopid "pelycosaur" is published in the December issue of Naturwissenschaften -- The Science of Nature. Professors Sean Modesto from Cape Breton University, and Robert Reisz from the University of Toronto Mississauga, provide evidence that a group of ancient, agile predators called varanopids survived for more than 35 million years, and co-existed with more advanced animals.

Modesto and the team performed a detailed examination of the partial skull and jaw of the youngest known primitive mammal-like animal, which they believe lived over 260 million years ago in the Permian Period. The fossils are from rocks forming the Pristerognathus Assemblage Zone of the Beaufort Group in South Africa.

"These animals were the most agile predators of their time, sleek-looking when compared to their contemporaries," says Reisz. "They seem to have survived a major change in the terrestrial fauna that occurred during the Middle Permian, a poorly understood extinction event in the history of life on land."

According to Modesto, "These ancient animals really looked like modern goannas or monitor lizards, but are actually more closely related to mammals."

The fossil revealed teeth that are strongly flattened, curved towards the throat and with finely serrated cutting edges typical of hypercarnivores -- animals with a diet that consists of more than 70 percent meat.

Modesto and his colleagues concluded that these varanopids had a longer co-existence with animals that eventually evolved into mammals than previously believed. They suggest that the dental and skeletal design of varanopids, reminiscent of the Komodo dragon of today, may have contributed to their long survival and their success.

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The above story is reprinted from materials provided by Springer.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

1. Sean P. Modesto, Roger M. H. Smith, Nicolás E. Campione, Robert R. Reisz. The last 'pelycosaur': a varanopid synapsid from the Pristerognathus Assemblage Zone, Middle Permian of South Africa. Naturwissenschaften, 2011; 98 (12): 1027 DOI: 10.1007/s00114-011-0856-2

http://www.sciencedaily.com/releases/2011/12/111206101456.htm
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"All truth passes through three stages. First, it is ridiculed, second it is violently opposed, and third, it is accepted as self-evident."

Arthur Schopenhauer, Philosopher, 1788-1860

"In the final analysis, our most basic common link is that we all inhabit this small planet, breathe the same air, and we all cherish our children’s future."

John F. Kennedy
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Re: Digging In The Dirt V
« Reply #64 on Dec 7, 2011, 8:13am »
New Horned Dinosaur Announced Nearly 100 Years After Discovery

[image]
Life restoration of Spinops. (Credit: Copyright Dmitry Bogdanov.)

ScienceDaily (Dec. 6, 2011) — A new species of horned dinosaur was just announced by an international team of scientists led by Alf Museum staff, 95 years after the initial discovery of the fossil.

The animal, named Spinops sternbergorum, lived approximately 76 million years ago in southern Alberta, Canada.

Spinops was a plant-eater that weighed around two tons when alive, a smaller cousin of Triceratops. A single large horn projected from the top of the nose, and a bony neck frill sported at least two long, backward-projecting spikes as well as two forward-curving hooks. These unique structures distinguish Spinops from related horned dinosaurs.

"I was amazed to learn the story behind these specimens, and how they went unstudied for so long," said Andrew Farke, Augustyn Family Curator of Paleontology at the Raymond M. Alf Museum of Paleontology, and lead author on the study naming Spinops. "This animal is an important addition to our understanding of horned dinosaur diversity and evolution," Farke continued.

Parts of the skulls of at least two Spinops were discovered in 1916 by Charles H. and Levi Sternberg, a father-and-son fossil collecting team. The Sternbergs recognized that their find represented a new species and sent the fossils to The Natural History Museum (London). However, the fossils were deemed too scrappy for exhibit, and consequently were shelved for decades. It wasn't until Farke and colleagues recognized the importance of the fossil that the bones were finally cleaned for study.

"This study highlights the importance of museum collections for understanding the history of our planet," commented Farke. "My colleagues and I were pleasantly surprised to find these fossils on the museum shelf, and even more astonished when we determined that they were a previously unknown species of dinosaur."

The name Spinops sternbergorum (pronounced "SPIN-ops stern-berg-OR-uhm") means "Sternbergs' spine face," referring to the headgear of the animal and honoring the original discoverers of the fossil. Although the face of Spinops is similar to its close relatives Centrosaurus and Styracosaurus, the unique anatomy of the bony neck frill gives scientists better insight into how this structure evolved. In particular, the fossils of Spinops clarify the identification of the long frill spikes common in some horned dinosaurs. Previously, scientists had inferred that these spikes evolved only once in the group. Careful study of Spinops, however,suggests that its spikes are located in a different position from that seen in most other horned dinosaurs, implying that the structures evolved independently. This finding allows a more accurate reconstruction of evolutionary relationships, and is being tested with additional study.

Story Source:

The above story is reprinted from materials provided by Raymond M. Alf Museum of Paleontology.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

1. Farke, A. A., M. J. Ryan, P. M. Barrett, D. H. Tanke, D. R. Braman, M. A. Loewen, and M. R. Graham. A new centrosaurine from the Late Cretaceous of Alberta, Canada, and the evolution of parietal ornamentation in horned dinosaurs. Acta Palaeontologica Polonica, 56(4) DOI: 10.4202/app.2010.0121

http://www.sciencedaily.com/releases/2011/12/111206115051.htm
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"All truth passes through three stages. First, it is ridiculed, second it is violently opposed, and third, it is accepted as self-evident."

Arthur Schopenhauer, Philosopher, 1788-1860

"In the final analysis, our most basic common link is that we all inhabit this small planet, breathe the same air, and we all cherish our children’s future."

John F. Kennedy
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Re: Digging In The Dirt V
« Reply #65 on Dec 17, 2011, 11:56am »
Dinosaurs With Killer Claws Yield New Theory About Evolution of Flight

ScienceDaily (Dec. 14, 2011) — New research from Montana State University's Museum of the Rockies has revealed how dinosaurs like Velociraptor and Deinonychus used their famous killer claws, leading to a new hypothesis on the evolution of flight in birds.

In a paper published Dec. 14 in PLoS ONE, MSU researchers Denver W. Fowler, Elizabeth A. Freedman, John B. Scannella and Robert E. Kambic (now at Brown University in Rhode Island), describe how comparing modern birds of prey helped develop a new behavior model for sickle-clawed carnivorous dinosaurs like Velociraptor.

"This study is a real game-changer," said lead author Fowler. "It completely overhauls our perception of these little predatory dinosaurs, changing the way we think about their ecology and evolution."

The study focuses on dromaeosaurids; a group of small predatory dinosaurs that include the famous Velociraptor and its larger relative, Deinonychus. Dromaeosaurids are closely related to birds, and are most famous for possessing an enlarged sickle-claw on digit two (inside toe) of the foot. Previous researchers suggested that this claw was used to slash at prey, or help climb up their hides, but the new study proposes a different behavior.

"Modern hawks and eagles possess a similar enlarged claw on their digit 2's, something that hadn't been noted before we published on it back in 2009," Fowler said. "We showed that the enlarged D-2 claws are used as anchors, latching into the prey, preventing their escape. We interpret the sickle claw of dromaeosaurids as having evolved to do the same thing: latching in, and holding on."

As in modern birds of prey, precise use of the claw is related to relative prey size.

"This strategy is only really needed for prey that are about the same size as the predator; large enough that they might struggle and escape from the feet," Fowler said. "Smaller prey are just squeezed to death, but with large prey all the predator can do is hold on and stop it from escaping, then basically just eat it alive. Dromaeosaurs lack any obvious adaptations for dispatching their victims, so just like hawks and eagles, they probably ate their prey alive too."

Other features of bird of prey feet gave clues as to the functional anatomy of their ancient relatives; toe proportions of dromaeosaurids seemed more suited for grasping than running, and the metatarsus (bones between the ankles and the toes) is more adapted for strength than speed.

"Unlike humans, most dinosaurs and birds only walk on their toes, so the metatarsus forms part of the leg itself," Fowler said. "A long metatarsus lets you take bigger strides to run faster; but in dromaeosaurids, the metatarsus is very short, which is odd."

Fowler thinks that this indicates that Velociraptor and its kin were adapted for a strategy other than simply running after prey.

"When we look at modern birds of prey, a relatively short metatarsus is one feature that gives the bird additional strength in its feet," Fowler continued. "Velociraptor and Deinonychus also have a very short, stout metatarsus, suggesting that they had great strength but wouldn't have been very fast runners."

The ecological implications become especially interesting when dromaeosaurids are contrasted with their closest relatives: a very similar group of small carnivorous dinosaurs called troodontids, Fowler said.

"Troodontids and dromaeosaurids started out looking very similar, but over about 60 million years they evolved in opposite directions, adapting to different niches," Fowler said. "Dromaeosaurids evolved towards stronger, slower feet; suggesting a stealthy ambush predatory strategy, adapted for relatively large prey. By contrast, troodontids evolved a longer metatarsus for speed and a more precise, but weaker grip, suggesting they were swift but probably took relatively smaller prey."

The study also has implications for the next closest relatives of troodontids and dromaeosaurids: birds. An important step in the origin of modern birds was the evolution of the perching foot.

"A grasping foot is present in the closest relatives of birds, but also in the earliest birds like Archaeopteryx," Fowler said. "We suggest that this originally evolved for predation, but would also have been available for use in perching. This is what we call 'exaptation:' a structure evolved originally for one purpose that can later be appropriated for a different use."

The new study proposes that a similar mechanism may be responsible for the evolution of flight.

"When a modern hawk has latched its enlarged claws into its prey, it can no longer use the feet for stabilization and positioning," Fowler said. "Instead the predator flaps its wings so that the prey stays underneath its feet, where it can be pinned down by the predator's bodyweight."

The researchers suggest that this 'stability flapping' uses less energy than flight, making it an intermediate flapping behavior that may be key to understanding how flight evolved.

"The predator's flapping just maintains its position, and does not need to be as powerful or vigorous as full flight would require. Get on top, stay on top; it's not trying to fly away," Fowler said. "We see fully formed wings in exquisitely preserved dromaeosaurid fossils, and from biomechanical studies we can show that they were also able to perform a rudimentary flapping stroke. Most researchers think that they weren't powerful enough to fly; we propose that the less demanding stability flapping would be a viable use for such a wing, and this behavior would be consistent with the unusual adaptations of the feet."

Another group of researchers has proposed that understanding flapping behaviors is key to understanding the evolution of flight, a view with which Fowler agrees.

"If we look at modern birds, we see flapping being used for all sorts of behaviors outside of flight. In our paper, we are formally proposing the 'flapping first' model: where flapping evolved for other behaviors first, and was only later exapted for flight by birds."

The researchers believe their new ideas will open multiple new lines of investigation into dinosaur paleobiology, and the evolution of novel anatomical structures.

"As with other research conducted at the Jack Horner paleo lab, we're looking at old paleontological questions with a fresh perspective, taking a different angle," Fowler said. "Just as you have to get beyond the idea that feet are used just for walking, so we are coming to realize that many unusual structures in modern animals originally evolved for quite different purposes. Revealing the selection pathways that mold and produce these structures helps us to better understand the major evolutionary transitions that shaped life on this planet."

Story Source:

The above story is reprinted from materials provided by Montana State University.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

1. Denver W. Fowler, Elizabeth A. Freedman, John B. Scannella, Robert E. Kambic. The Predatory Ecology of Deinonychus and the Origin of Flapping in Birds. PLoS ONE, 2011; 6 (12): e28964 DOI: 10.1371/journal.pone.0028964

http://www.sciencedaily.com­/releases/2011/12/111214171541.htm
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"All truth passes through three stages. First, it is ridiculed, second it is violently opposed, and third, it is accepted as self-evident."

Arthur Schopenhauer, Philosopher, 1788-1860

"In the final analysis, our most basic common link is that we all inhabit this small planet, breathe the same air, and we all cherish our children’s future."

John F. Kennedy
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Re: Digging In The Dirt V
« Reply #66 on Dec 20, 2011, 5:33am »
19 December 2011 Last updated at 12:30 GMT

Stonehenge rocks Pembrokeshire link confirmed

[image]
Archaeologists hope the find will enable them to discover how the stones were transported to Stonehenge

Experts say they have confirmed for the first time the precise origin of some of the rocks at Stonehenge.

It has long been suspected that rhyolites from the northern Preseli Hills helped build the monument.

But research by National Museum Wales and Leicester University has identified their source to within 70m (230ft) of Craig Rhos-y-felin, near Pont Saeson.

The museum's Dr Richard Bevins said the find would help experts work out how the stones were moved to Wiltshire.

For nine months Dr Bevins, keeper of geology at National Museum Wales, and Dr Rob Ixer of Leicester University collected and identified samples from rock outcrops in Pembrokeshire to try to find the origins of rhyolite debitage rocks that can be found at Stonehenge.

By detailing the mineral content and the textural relationships within the rock, a process known as petrography, they found that 99% of the samples could be matched to rocks found in this particular set of outcrops.

Rhyolitic rocks at Rhos-y-felin, between Ffynnon-groes (Crosswell) and Brynberian, differ from all others in south Wales, they said, which helps locate almost all of Stonehenge's rhyolites to within hundreds of square metres.

Within that area, the rocks differ on a scale of metres or tens of metres, allowing Dr Bevins and Dr Ixer to match some Stonehenge rock samples even more precisely to a point at the extreme north-eastern end of Rhos-y-felin.

Dr Rob Ixer of Leicester University called the discovery of the source of the rocks "quite unexpected and exciting".

'Perseverance'

"Being able to provenance any archaeologically significant rock so precisely is remarkable," he said.

"However, given continued perseverance, we are determined that we shall uncover the origins of most, if not all of the Stonehenge bluestones so allowing archaeologists to continue their speculations well into a third century."

With the location identified, archaeologists will now be able to dig to try and uncover how the stones from Pembrokeshire reached Stonehenge.

[image]
The rocks were traced to the Pont Saeson area

"Many have asked the question over the years, how the stones got from Pembrokeshire to Stonehenge," said Dr Bevins. "Was it human transport? Was it due to ice transport?

"Thanks to geological research, we now have a specific source for the rhyolite stones from which to work and an opportunity for archaeologists to answer the question that has been widely debated.

"It is important now that the research continues."

Work is continuing to identify the source of four other stones at Stonehenge which do not come from Rhos-y-felin, he said.

Theory

Experts have long theorised on how the stones were transported from Pembrokeshire to the Stonehenge site when the monument was built from around 3000 BC to 1600 BC.

Perceived wisdom had it that the giant slabs were moved via raft, up the Bristol Channel and River Avon.

But as Pont Saeson is to the north of the Preselis some believe its unlikely that they would have been able to navigate the terrain in order to get the enormous rocks to the coast.

An alternative theory was that nature drove the stone to Stonehenge, in the path of an Ice Age glacier, although the absence of any other Welsh rock in the region seemed to have ruled out the possibility.

In April 2000 a National Lottery Heritage Lottery Fund plan was launched to replicate the 240-mile (386 km) journey of a giant stone from west Wales to Salisbury Plain, by land and sea.

The millennium bluestone project, which tried to use only muscle power and the technology of the ancients, ended in disaster when the stone sank in Milford Haven estuary.

http://www.bbc.co.uk/news/uk-wales-south-west-wales-16245746
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Re: Digging In The Dirt V
« Reply #67 on Dec 25, 2011, 8:26pm »
Ancient Jewish rituals confirmed by discovery of purity seal, Israeli archaeologists say

Reuters Dec 25, 2011 – 12:45 PM ET

[image]
Israel Antiquities Authority (IAA) archaeologist Eli Shukron shows an ancient seal, at an archaeological site known as the City of David in Jerusalem December 25, 2011. Israeli archaeologists said on Sunday they had found the 2,000-year-old clay seal near Jerusalem's Western Wall, confirming written accounts of ritual practices in the biblical Jewish Temple. Baz Ratner/REUTERS

JERUSALEM — Israeli archaeologists said on Sunday they had found a 2,000-year-old clay seal near Jerusalem’s Western Wall, confirming written accounts of ritual practices in the biblical Jewish Temple.

The button-shaped object bears the Aramaic words “pure for God,” suggesting it was used to certify food and animals used in sacrificial ceremonies.

The Western Wall is part of the compound revered by Jews as the Temple Mount, where Islam’s al-Aqsa mosque and Dome of the Rock shrine now stand in a holy complex Muslims call the Noble Sanctuary.

“It seems that the inscribed object was used to mark products or objects that were brought to the Temple, and it was imperative they be ritually pure,” the Israel Antiquities Authority said in a statement announcing the find.

The authority said it believed it was the first time such a seal had been excavated, providing direct archaeological evidence of ritual activity in the temple described in ancient texts.

http://news.nationalpost.com/2011/12/25/....eo logists-say/
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Re: Digging In The Dirt V
« Reply #68 on Dec 26, 2011, 5:45pm »
Cemetery sheds light on slavery
Tom Phillips
December 27, 2011

RIO DE JANEIRO: Locals called it the cemetery of the new blacks, but it was a cemetery only in name. Devoid of headstones, wreaths or tearful mourners, this squalid harbourside burial ground was the final resting place for thousands of Africans shipped into slavery.

The New World greeted them with a lonely death in an unfamiliar land. For decades the cemetery and those buried there between 1760 and 1830 were forgotten, hidden under layer after layer of urban development.

But 15 years after the cemetery's discovery - when builders unearthed a series of muddy skeletons - academics now believe they have evidence of the true reach of the slave trade.

The study of teeth from 30 partial skeletons has hinted that slaves arriving in Rio - many of whom were sold on to work in coffee and sugar plantations or goldmines - came from a much wider geographical region than once thought.

Archaeologists and anthropologists studying bone and tooth fragments are shedding light on the horrors of a trade in which at least 3 million slaves were shipped from Africa to Brazil between 1550 and 1888, when the practice was abolished.

''It was ugly: a dump into which bodies were thrown and burnt,'' said Sheila Mendonca de Souza, a bio-archaeologist studying the cemetery in Rio de Janeiro, once one of the busiest slave ports in the Americas.

Using strontium isotope analyses of tooth enamel, academics were able to confirm the large area from where the ''new blacks'' came.

The results indicated that slavers had ''waded way into the interior'' of Africa instead of restricting their search to coastal areas, said Della Cook, a biological anthropologist from the University of Indiana.

A parallel study of cosmetic tooth modifications, common in some regions of Africa, also underlined the scope of the slave trade.

Dr Mendonca said her team had found tooth markings indicating some of the slaves were native to what are now Sudan and Mozambique, in north-eastern and southern Africa.

Archaeologists believe as many as 20,000 slaves may have been buried at the cemetery, mostly men between 18 and 25 years of age, who died during the gruelling journey to Brazil or shortly after arriving.

The 3 million slaves who made the journey were previously thought to have come only from what is now Nigeria and from the Portuguese colonies of Angola and Cape Verde.

Read more: http://www.smh.com.au/world/cemetery-she....l#ixzz1hgR05NGq
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Re: Digging In The Dirt V
« Reply #69 on Dec 29, 2011, 7:34am »
Over 65 Million Years, North American Mammal Evolution Has Tracked With Climate Change

[image]
Rhino-like animals. This painting by artist Carl Buell depcits a scene from the late Eocene of North America. The rhino-like animals in the background are brontotheres. The pony-sized Hyracodon, a closer relative of living rhinos, in the foreground. (Credit: Carl Buell)

ScienceDaily (Dec. 27, 2011) — Climate changes profoundly influenced the rise and fall of six distinct, successive waves of mammal species diversity in North America over the last 65 million years, shows a novel statistical analysis led by Brown University evolutionary biologists. Warming and cooling periods, in two cases confounded by species migrations, marked the transition from one dominant grouping to the next.

History often seems to happen in waves -- fashion and musical tastes turn over every decade and empires give way to new ones over centuries. A similar pattern characterizes the last 65 million years of natural history in North America, where a novel quantitative analysis has identified six distinct, consecutive waves of mammal species diversity or "evolutionary faunas." What force of history determined the destiny of these groupings? The numbers say it was typically climate change.

"Although we've always known in a general way that mammals respond to climatic change over time, there has been controversy as to whether this can be demonstrated in a quantitative fashion," said Christine Janis, professor of evolutionary biology at Brown University. "We show that the rise and fall of these faunas is indeed correlated with climatic change -- the rise or fall of global paleotemperatures -- and also influenced by other more local perturbations such as immigration events."

Specifically, of the six waves of species diversity that Janis and her Spanish collaborators recently describe online in Proceedings of the National Academy of Sciences, four show statistically significant correlations with major changes in temperature. The two transitions that show a weaker but still apparent correlation with the pattern correspond to periods when mammals from other continents happened to invade in large numbers, said Janis, who is the paper's senior and second author.

Previous studies of the potential connection between climate change and mammal species evolution have counted total species diversity in the fossil record over similar time periods. But in this analysis, led by postdoctoral scholar Borja Figueirido, the scientists asked whether there were any patterns within the species diversity that might be significant. They were guided by a similar methodology pioneered in a study of "evolutionary faunas" in marine invertebrates by Janis' late husband Jack Sepkoski, who was a paleontologist at the University of Chicago.

What the authors found is six distinct and consecutive groupings of mammal species that shared a common rise, peak, and decline in their numbers. For example, the "Paleocene fauna" had largely given way to the "early-middle Eocene fauna" by about 50 million years ago. Moreover, the authors found that these transfers of dominance correlated with temperature shifts, as reflected in data on past levels of atmospheric oxygen (determined from the isotopes in the fossilized remains of deep sea microorganisms).

By the numbers, the research showed correlations between species diversity and temperature change, but qualitatively, it also provided a narrative of how the traits of typical species within each wave made sense given the changes in vegetation that followed changes in climate. For example, after a warming episode about 20 million years in the early Miocene epoch, the dominant vegetation transitioned from woodland to a savannah-like grassland. It is no surprise, therefore, that many of the herbivores that comprised the accompanying "Miocene fauna" had high-crowned teeth that allowed them to eat the foods from those savannah sources.

To the extent that the study helps clarify scientists' understanding of evolution amid climate changes, it does not do so to the extent that they can make specific predictions about the future, Janis said. But it seems all the clearer that climate change has repeatedly had meaningful effect over millions of years.

"Such perturbations, related to anthropogenic climatic change, are currently challenging the fauna of the world today, emphasizing the importance of the fossil record for our understanding of how past events affected the history of faunal diversification and extinction, and hence how future climactic changes may continue to influence life on earth," the authors wrote in the paper.

In addition to Janis and Figueirido at Brown, the other authors are Juan Perez-Claros and Paul Palmqvist at the University of Malaga and Miguel De Renzi at the University of Valencia in Spain. Figueirido is also affiliated with Malaga.

Grants from the Fulbright program, the Bushnell Foundation (to Brown) and the Spanish Ministry of Science and Innovation funded the research.

Story Source:

The above story is reprinted from materials provided by Brown University.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

1. Borja Figueirido, Christine M. Janis, Juan A. Pérez-Claros, Miquel De Renzi, and Paul Palmqvist. Cenozoic climate change influences mammalian evolutionary dynamics. PNAS, December 27, 2011 DOI: 10.1073/pnas.1110246108

http://www.sciencedaily.com­/releases/2011/12/111227093055.htm
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Re: Digging In The Dirt V
« Reply #70 on Dec 29, 2011, 7:51am »
New Theory Emerges for Where Some Fish Became Four-Limbed Creatures

[image]
Romer's desert hypothesis, left, and Retallack's flooded woodland, right. (Credit: Image courtesy of University of Oregon)

ScienceDaily (Dec. 27, 2011) — A small fish crawling on stumpy limbs from a shrinking desert pond is an icon of can-do spirit, emblematic of a leading theory for the evolutionary transition between fish and amphibians. This theorized image of such a drastic adaptation to changing environmental conditions, however, may, itself, be evolving into a new picture.

University of Oregon scientist Gregory J. Retallack, professor of geological sciences, says that his discoveries at numerous sites in Maryland, New York and Pennsylvania suggests that "such a plucky hypothetical ancestor of ours probably could not have survived the overwhelming odds of perishing in a trek to another shrinking pond."

This scenario comes from the late Devonian, about 390 million years ago to roughly 360 million years ago. Paleontologist Alfred Romer, who died in 1973 after serving on the faculties at the University of Chicago and Harvard University, saw this time as a period of struggle and escape -- and important in fish-tetrapod transition -- to ensure survival.

Reporting in the May 2011 issue of the Journal of Geology, Retallack, who also is co-director of paleontological collections at the UO's Museum of Natural and Cultural History, argues for a very different explanation. He examined numerous buried soils in rocks yielding footprints and bones of early transitional fossils between fish and amphibians of Devonian and Carboniferous geological age. What he found raises a major challenge to Romer's theory.

"These transitional fossils were not associated with drying ponds or deserts, but consistently were found with humid woodland soils," he said. "Remains of drying ponds and desert soils also are known and are littered with fossil fish, but none of our distant ancestors. Judging from where their fossils were found, transitional forms between fish and amphibians lived in wooded floodplains. Our distant ancestors were not so much foolhardy, as opportunistic, taking advantage of floodplains and lakes choked with roots and logs for the first time in geological history."

Limbs proved handy for negotiating woody obstacles, and flexible necks allowed for feeding in shallow water, Retallack said. By this new woodland hypothesis, the limbs and necks, which distinguish salamanders from fish, did not arise from reckless adventure in deserts, but rather were nurtured by a newly evolved habitat of humid, wooded floodplains.

The findings, he said, dampen both the desert hypothesis of Romer and a newer inter-tidal theory put forth by Grzegorz Niedbwiedzki and colleagues at the University of Warsaw. In 2010, they published their discovery of eight-foot-long, 395-million-year-old tetrapods in ancient lagoonal mud in southeastern Poland, where Retallack also has been studying fossil soils with Polish colleague Marek Narkeiwicz.

"Ancient soils and sediments at sites for transitional fossils around the world are critical for understanding when and under what conditions fish first walked," Retallack said. "The Darwin fish of chrome adorning many car trunks represents a particular time and place in the long evolutionary history of life on earth." UO Academic Support Funds supported Retallack's research.

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The above story is reprinted from materials provided by University of Oregon.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

1. Gregory J. Retallack. Woodland Hypothesis for Devonian Tetrapod Evolution. The Journal of Geology, 2011; 119 (3): 235 DOI: 10.1086/659144

http://www.sciencedaily.com/releases/2011/12/111227142628.htm
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Re: Digging In The Dirt V
« Reply #71 on Dec 29, 2011, 9:34am »
Attic Vases from Athens Inspired Cypriote Pottery

ScienceDaily (Dec. 20, 2011) — Athenian pottery was exported to both east and west. In Cyprus the pottery was exported for about 300 years and it became a part of the Cypriots' life. It also inspired the local potters and painters to create their own versions of the imagery and enrich them with local elements. This is described in a new doctoral thesis from the University of Gothenburg, Sweden.

Niki Eriksson, who has studied the Attic pottery found in Cyprus, points out that the pottery was imported from the early 500s BC to the late 300 BC, she also adds that a similar distribution to the Eastern Mediterranean suggests that a great part of the Cypriote import is of the same mercantile transactions, which were operated by the Phoenicians. There are, however, reasons to believe that there were direct commercial contacts with Athens and that private individuals who visited Athens brought some of the pottery to Cyprus.

Cypriots showed a particular preference for drinking vessels and perfume flasks. Niki Eriksson suggests that the Cypriots wanted a precious piece of pottery that they could use in their everyday activities and at the same time honor their gods and dead ancestors. Kraters which, were big bowls in which wine and water was mixed were the most popular votive gifts and were most probably used during the religious festivities.

The iconographical representations reflect the imaginary world of the Greeks. By studying the iconography one may follow the art development, the personalities of the pottery painters and the taste of the different customers.

The popularity of the pottery owed not only to its high quality but also to its rich iconography, which enabled the customer to use it in different occasions as for example the religious feasts at the sanctuaries where the rituals and the visual symbols found on the vessels helped the island's inhabitants to form common culture and identities.

Thesis: http://gupea.ub.gu.se/handle/2077/27996

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http://www.sciencedaily.com/releases/2011/12/111220133608.htm
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Re: Digging In The Dirt V
« Reply #72 on Dec 29, 2011, 9:38am »
Human Skull Is Highly Integrated: Study Sheds New Light On Evolutionary Changes

[image]
The study is based on the analysis of 390 decorated skulls from the ossuary in Hallstatt (Austria). (Credit: Image courtesy of University of Barcelona)

ScienceDaily (Dec. 20, 2011) — Scientists studying a unique collection of human skulls have shown that changes to the skull shape thought to have occurred independently through separate evolutionary events may have actually precipitated each other.

Researchers at the Universities of Manchester and Barcelona examined 390 skulls from the Austrian town of Hallstatt and found evidence that the human skull is highly integrated, meaning variation in one part of the skull is linked to changes throughout the skull.

The Austrian skulls are part of a famous collection kept in the Hallstatt Catholic Church ossuary; local tradition dictates that the remains of the town's dead are buried but later exhumed to make space for future burials. The skulls are also decorated with paintings and, crucially, bear the name of the deceased. The Barcelona team made measurements of the skulls and collected genealogical data from the church's records of births, marriages and deaths, allowing them to investigate the inheritance of skull shape.

The team tested whether certain parts of the skull -- the face, the cranial base and the skull vault or brain case -- changed independently, as anthropologists have always believed, or were in some way linked. The scientists simulated the shift of the foramen magnum (where the spinal cord enters the skull) associated with upright walking; the retraction of the face, thought to be linked to language development and perhaps chewing; and the expansion and rounding of the top of the skull, associated with brain expansion. They found that, rather than being separate evolutionary events, changes in one part of the brain would facilitate and even drive changes in the other parts.

"We found that genetic variation in the skull is highly integrated, so if selection were to favour a shape change in a particular part of the skull, there would be a response involving changes throughout the skull," said Dr Chris Klingenberg, in Manchester's Faculty of Life Sciences.

"We were able to use the genetic information to simulate what would happen if selection were to favour particular shape changes in the skull. As those changes, we used the key features that are derived in humans, by comparison with our ancestors: the shift of the foramen magnum associated with the transition to bipedal posture, the retraction of the face, the flexion of the cranial base, and, finally, the expansion of the braincase.

"As much as possible, we simulated each of these changes as a localised shape change limited to a small region of the skull. For each of the simulations, we obtained a predicted response that included not only the change we selected for, but also all the others. All those features of the skull tended to change as a whole package. This means that, in evolutionary history, any of the changes may have facilitated the evolution of the others."

Lead author Dr Neus Martínez-Abadías, from the University of Barcelona, added: "This study has important implications for inferences on human evolution and suggests the need for a reinterpretation of the evolutionary scenarios of the skull in modern humans."

The research, funded by the Wenner Gren Foundation for Anthropological Research (USA) and the Spanish Ministry of Education and Science, is published in the journal Evolution.

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The above story is reprinted from materials provided by Manchester University.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

1. Neus Martínez-Abadías, Mireia Esparza, Torstein Sjøvold, Rolando González-José, Mauro Santos, Miquel Hernández, Christian Peter Klingenberg. Pervasive genetic integration directs the evolution of human skull shape. Evolution, 2011; DOI: 10.1111/j.1558-5646.2011.01496.x

http://www.sciencedaily.com/releases/2011/12/111220102248.htm
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Re: Digging In The Dirt V
« Reply #73 on Dec 29, 2011, 9:42am »
Heritage Site Under Attack by Flowers

[image]
North and South gates of the Belgrade fortress. (Credit: © V. Matovic)

ScienceDaily (Dec. 22, 2011) — The results of a study conducted by Serbian researchers, in collaboration with the Laboratoire de Dynamique, Interactions et Réactivité (LADIR, CNRS/UPMC), are unequivocal: the Belgrade fortress is not only threatened by the effects of coal burning, as was assumed until now, but also by flower beds! The deterioration of the fortress walls could be partially caused by the large quantities of potassium present in fertilizers used by gardeners and could be responsible for the formation of black crusts on the ramparts. To preserve this heritage, the researchers recommend avoiding excessive use of fertilizers.

Their conclusions are due to be published in the first quarter of 2012 in the Journal of Cultural Heritage and could prove to be of value to other historical sites across the world.

In Belgrade, fortifications were built from the Middle Ages on the Kalemegdan plateau, which stands above the confluence of the Danube and Sava rivers. Today, the ramparts of the fortress of the Serbian capital have become a vast public park with flowers and shady areas, near the town centre, attracting inhabitants and tourists alike. However, during the last twenty years or so, black crusts have been spreading on its limestone walls. Until now, these crusts were solely attributed to the high levels of sulfur dioxide released by the coal heating used by the inhabitants of Belgrade.

In collaboration with Philippe Colomban, CNRS researcher at LADIR, the University of Belgrade and the Serbian Highway Institute analyzed the black crusts on the "King's Gate" of the fortress. Their objective was to determine the actual deterioration process in order to propose the most appropriate conservation solutions to the authorities. Different samples of the limestone and lime mortars were studied by porometry*, X-ray diffractometry, infrared and Raman spectroscopy, electron microscopy and elementary analysis.

Above a certain concentration of sulfur dioxide in damp air, acid rain or acid fog can form. This leads to the emergence of "black" calcium sulfates and carbonates, giving the outer walls a somewhat unsightly appearance. Surprisingly enough, the researchers detected large amounts of syngenite, a double sulfate of potassium and calcium. This corrosion product normally forms on potassium-containing medieval stained-glass windows, as well as granite constructions or those using a mortar containing potassium. Yet it had never been observed on very pure limestone before.

So where does it come from? After performing a series of analyses, the researchers revealed an abnormal concentration of potassium in the soil, near the rampart walls. Incidently, the latter contain flowerbeds where potassium-rich fertilizers are used. A simulation of the action of acidified potassium-charged water on pieces of limestone confirmed that it triggered the formation of syngenite, as observed on the "King's Gate."

Pretty flowers and monument preservation therefore require a subtle balance in potassium input in order to avoid such pollution. On-site measurements are scheduled to map the extent of the phenomenon.

* Study of the distribution of voids in a porous material.

Story Source:

The above story is reprinted from materials provided by CNRS (Délégation Paris Michel-Ange).

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

1. Vesna Matović, Suzana Erić, Aleksandar Kremenović, Philippe Colomban, Danica Srećković-Batoćanin, Nenad Matović. The origin of syngenite in black crusts on the limestone monument King's Gate (Belgrade Fortress, Serbia) – the role of agriculture fertiliser. Journal of Cultural Heritage, 2011; DOI: 10.1016/j.culher.2011.09.003

http://www.sciencedaily.com/releases/2011/12/111222102915.htm
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Re: Digging In The Dirt V
« Reply #74 on Dec 29, 2011, 9:53am »
Skeletons Point to Columbus Voyage for Syphilis Origins

[image]
A biopsy of Treponema pallidum spirochetes in tissue. In 2008, anthropologist Kristin Harper completed a comprehensive comparative genetic analysis of syphilis's family of bacteria. The results further supported the Columbus theory for its origins. (Credit: CDC)

ScienceDaily (Dec. 20, 2011) — Skeletons don't lie. But sometimes they may mislead, as in the case of bones that reputedly showed evidence of syphilis in Europe and other parts of the Old World before Christopher Columbus made his historic voyage in 1492.

None of this skeletal evidence, including 54 published reports, holds up when subjected to standardized analyses for both diagnosis and dating, according to an appraisal in the current Yearbook of Physical Anthropology. In fact, the skeletal data bolsters the case that syphilis did not exist in Europe before Columbus set sail.

"This is the first time that all 54 of these cases have been evaluated systematically," says George Armelagos, an anthropologist at Emory University and co-author of the appraisal. "The evidence keeps accumulating that a progenitor of syphilis came from the New World with Columbus' crew and rapidly evolved into the venereal disease that remains with us today."

The appraisal was led by two of Armelagos' former graduate students at Emory: Molly Zuckerman, who is now an assistant professor at Mississippi State University, and Kristin Harper, currently a post-doctoral fellow at Columbia University. Additional authors include Emory anthropologist John Kingston and Megan Harper from the University of Missouri.

"Syphilis has been around for 500 years," Zuckerman says. "People started debating where it came from shortly afterwards, and they haven't stopped since. It was one of the first global diseases, and understanding where it came from and how it spread may help us combat diseases today."

The history of syphilis, and society's reactions to the disease, have eerie parallels to the more modern story of HIV/AIDS.

The treponemal family of bacteria causes syphilis and related diseases that share some symptoms but spread differently. Syphilis is sexually transmitted. Yaws and bejel, which occurred in early New World populations, are tropical diseases that are transmitted through skin-to-skin contact or oral contact.

The first recorded epidemic of venereal syphilis occurred in Europe in 1495. One hypothesis is that a subspecies of Treponema from the warm, moist climate of the tropical New World mutated into the venereal subspecies to survive in the cooler and relatively more hygienic European environment.

The fact that syphilis is a stigmatized, sexual disease has added to the controversy over its origins, Zuckerman says.

"In reality, it appears that venereal syphilis was the by-product of two different populations meeting and exchanging a pathogen," she says. "It was an adaptive event, the natural selection of a disease, independent of morality or blame."

Armelagos, a pioneer of the field of bioarcheology, was one of the doubters decades ago, when he first heard the Columbus theory for syphilis. "I laughed at the idea that a small group of sailors brought back this disease that caused this major European epidemic," he recalls.

While teaching at the University of Massachusetts, he and graduate student Brenda Baker decided to investigate the matter and got a shock: All of the available evidence at the time actually supported the Columbus theory. "It was a paradigm shift," Armelagos says. The pair published their results in 1988. In 2008, Harper and Armelagos published the most comprehensive comparative genetic analysis ever conducted on syphilis's family of bacteria. The results again supported the hypothesis that syphilis, or some progenitor, came from the New World.

But reports of pre-Columbian skeletons showing the lesions of chronic syphilis have kept cropping up in the Old World. For this latest appraisal of the skeletal evidence, the researchers gathered all of the published reports.

They found that most of the skeletal material did not meet at least one of the standardized, diagnostic criteria for chronic syphilis, including pitting on the skull known as caries sicca and pitting and swelling of the long bones.

The few published cases that did meet the criteria tended to come from coastal regions where seafood was a big part of the diet. The so-called "marine reservoir effect," caused by eating seafood which contains "old carbon" from upwelling, deep ocean waters, can throw off radiocarbon dating of a skeleton by hundreds, or even thousands, of years. Analyzing the collagen levels of the skeletal material enabled the researchers to estimate the seafood consumption and factor that result into the radiocarbon dating.

"Once we adjusted for the marine signature, all of the skeletons that showed definite signs of treponemal disease appeared to be dated to after Columbus returned to Europe," Harper says.

"The origin of syphilis is a fascinating, compelling question," Zuckerman says. "The current evidence is pretty definitive, but we shouldn't close the book and say we're done with the subject. The great thing about science is constantly being able to understand things in a new light."

Story Source:

The above story is reprinted from materials provided by Emory University. The original article was written by Carol Clark.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

1. Kristin N. Harper, Molly K. Zuckerman, Megan L. Harper, John D. Kingston, George J. Armelagos. The origin and antiquity of syphilis revisited: An Appraisal of Old World pre-Columbian evidence for treponemal infection. American Journal of Physical Anthropology, 2011; 146 (S53): 99 DOI: 10.1002/ajpa.21613

http://www.sciencedaily.com/releases/2011/12/111220134144.htm
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"All truth passes through three stages. First, it is ridiculed, second it is violently opposed, and third, it is accepted as self-evident."

Arthur Schopenhauer, Philosopher, 1788-1860

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John F. Kennedy
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