Life Originated in the Earth’s Crust

Heritage Daily - Sun, 2014-11-16 17:21
This at least is what the geologist Prof. Dr. Ulrich Schreiber and the physico-chemist Prof. Dr. Christian Mayer of the University of Duisburg-Essen in Germany are convinced of.

It is the first model on the origin of life which includes a complete process leading from inorganic chemistry to a protocell where the problems of molecule formation, local concentration, driving force and membrane formation are being solved simultaneously” Prof. Mayer from the faculty of Chemistry says.

What is this all about? The detailed environments on the early Earth and the conditions, under which life could originate billions of years ago are largely unknown. In consequence, the possible processes which may have taken place can neither be proven nor excluded. Therefore, most of the models proposed so far are focused on singular elementary steps of prebiotic developments. In its long history, the corresponding discussion about the crucial location on early Earth shifted from the Earth’s surface to the deep sea, from volcanic outlets to shallow ponds. Lacking plausible alternatives, extraterrestrial regions like Mars or the interplanetary space have also been included.

Credit : Universität Duisburg-Essen

On the other hand, the continental crust was, during a long time, neglected in the discussion. “This region, however, offers the ideal conditions for the origin of life“, Prof. Schreiber says.  His focus is on deep-reaching tectonic fault zones which are in contact with the Earth’s mantle. As for example in the region of the “Eifel” in Germany, they are channeling water, carbon dioxide and other gases which constantly rise to the surface. This fluid mixture contains all necessary ingredients for prebiotic organic chemistry.

One of the most intriguing aspects is the presence of supercritical carbon dioxide in depths below 800 meters. This supercritical fluid combines the properties of a liquid with those of a gas and presents an ideal solvent for organic chemical reactions. “This allows for many synthetic steps leading to complex biological molecules which otherwise, in a solvent like water, could not be accounted for”, Prof. Mayer explains, “Supercritical carbon dioxide acts like an organic solvent enabling reactions which would not occur in an aqueous environment. Moreover, it forms interfaces with water and hereby generates double-layer membranes which represent the most important single structural element of living cells”.

The fundamental steps of the proposed mechanisms have already been successfully reproduced in the laboratory. This includes the formation of vesicles as simple cell-like structures or the combination of amino acids to longer polymer chains forming the basis for proteins and enzymes. A fascinating detail is the fact that these processes may be proven today as they have left traces in minerals which have grown in the fault zones of the early Earth.

Prof. Oliver Schmitz, responsible for the field of trace analysis in the department of Chemistry in Essen, is convinced:  „Tiny fluid inclusions in crystals from Australian quartz dykes which have been collected by Prof. Schreiber contain a large collection of organic substances. They have been encapsulated from the fluid contents of the fault zone during the growth of the crystals. Today, they may help us to identify the chemistry which has taken place.“  With his profound experience in the analysis of natural compounds, Prof. Schmitz is a valuable asset in the research group at the University of Duisburg-Essen which deals with the fascinating question around the origin of life.

Universität Duisburg-Essen

Categories: General

VIDEO: New plans to curb prison staff attacks

BBC test - Sun, 2014-11-16 11:07
Prison officers in England and Wales are to receive greater protection from violent inmates under new measures from the Ministry of Justice, as serious assaults are at a record high.
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VIDEO: 'New format' for Songs of Praise

BBC test - Sun, 2014-11-16 09:35
Songs of Praise alters its traditional format to feature a broad range of Christian denominations.
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VIDEO: 'Epidemic of hunger' in the UK

BBC test - Sun, 2014-11-16 09:31
There is a 'silent epidemic of hunger' in the UK, according to a leading children's charity.
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VIDEO: Patients 'struggling to see GPs'

BBC test - Sun, 2014-11-16 09:13
Patients in England are struggling to book GP appointments, according to a report by the Care Quality Commission.
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VIDEO: Cameron: Putin at crossroads on Ukraine

BBC test - Sun, 2014-11-16 08:59
UK Prime Minister David Cameron says Russian President Vladimir Putin "can see he is at a crossroads" over Ukraine.
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VIDEO: Colchester Hospital 'major incident'

BBC test - Sat, 2014-11-15 23:00
Colchester Hospital warns patients to stay away from A&E except for "serious or life-threatening" conditions after inspectors raise concerns.
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VIDEO: Miliband hits out at Sports Direct

BBC test - Sat, 2014-11-15 22:53
Retailer Sports Direct has dismissed criticism by Ed Miliband of its use of zero-hours contracts.
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VIDEO: SNP 'could have balance of power'

BBC test - Sat, 2014-11-15 22:43
Nicola Sturgeon has used her first speech as SNP leader to predict the party could hold the "balance of power" after the next general election.
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VIDEO: Men rescue woman from sinking car

BBC test - Sat, 2014-11-15 18:29
Two men who helped rescue a pensioner from a sinking car in Portadown have been describing their role
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VIDEO: How energy saving can save pounds

BBC test - Sat, 2014-11-15 18:01
It is thought the UK needs to improve energy-saving measures in over 13,000 existing homes a week if it is to meet its greenhouse gas commitments.
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High-Tech Authentication of Ancient Artifacts

Heritage Daily - Sat, 2014-11-15 17:13
Geologist Timothy Rose of the Smithsonian Institution’s Analytical Laboratories is accustomed to putting his lab’s high-tech nanoscale scanning electron microscope (nanoSEM) to work evaluating the mineral composition of rocks and meteorites.

Lately, though, the nanoSEM has been enlisted for a different kind of task: determining the authenticity of ancient Mesoamerican artifacts.

A 17 cm carved stone figurine shown inside the SEM chamber ready for non-destructive imaging and analysis. CREDIT: T. Rose/Smithsonian

In ongoing studies, Rose and his colleague Jane Walsh have now analyzed hundreds of artifacts, including carved stone figurines and masks and ceramic pieces from the ancient Olmec, Maya, Teotihuacan and Mezcala civilizations dating from 1500 B.C. to A.D. 600. “With our modern imaging and analytical tools we can look at objects at very high magnification, which can reveal new details about how, and sometimes when, objects were created,” he said.

Rose will discuss the technology at the AVS 61th International Symposium and Exhibition, to be held Nov. 9-14, at the Baltimore Convention Center in Baltimore, Md.

The nanoSEM used by Rose and his colleagues has the ability to function over a range of pressures. “Being able to work in the low-vacuum mode allows us to put samples into the microscope au naturel without coating them with an electrically conductive material such as carbon, which would be almost impossible to remove from a specimen,” he said.

In one study, Rose and colleagues used the nanoSEM to study stone masks from Teotihuacan, a pre-Columbian site located 30 miles northwest of Mexico City. The masks, about the size of a human face, were too big to be put into the device (and, more importantly, could not be removed from their respective museums or drilled or otherwise altered to obtain samples for analysis). However, silicone molds that were made of the objects to study tool marks with an optical microscope did remove tiny mineral grains from deep within cracks and drill holes. Chemical evaluation of these grains using the nanoSEM’s X-ray spectrographic analysis system showed that some were diatoms—common single-celled algae with cell walls made of silica. Diatomaceous earth is “a very fine powdery siliceous rock comprised entirely of diatoms that would make very nice polish for the stone of these specific masks,” Rose said. “We believe we found abrasive grains and polish that was used in the manufacturing process.”

In a separate study of artifacts confiscated by the federal government, the researchers found some pieces to be partially coated with a layer of what looked to be modern gypsum plaster. In other words, the pieces were fakes. However, Rose noted, a surprisingly small percentage of the objects evaluated to date have shown modern tools marks or other evidence of recent origins. One unique ceramic handled pot analyzed in detail, for example, had five chemically distinct layers that appeared to be original Olmec fresco paint—a level of craftsmanship that, he said, is unlikely to have been the work of modern artisans.

Categories: General

Tell-tales of war: Traditional stories highlight how ancient women survived

Heritage Daily - Sat, 2014-11-15 17:07
Through the ages, women have suffered greatly because of wars. Consequently, to protect themselves and their offspring, our female ancestors may have evolved survival strategies specific to problems posed by warfare, says Michelle Scalise Sugiyama of the University of Oregon in the US.

Her findings, based on the comprehensive analysis of traditional stories from across the world, are published today in Springer’s journal Human Nature. The work is of interest because research to date has focused on the problems warfare poses for men, and how these problems shaped human male cognition.

Scalise Sugiyama studied a sample of forager and forager-horticulturalist societies by looking at archaeological and ethnographic research on lethal raiding. This helped her to compile a list of five ‘fitness costs’ – ways in which warfare impedes women’s chances of surviving and reproducing. These occur when a woman is killed, a woman is captured, her offspring is killed, a mate is killed or captured, or an adult male kinsman is killed or captured.

The study then reviewed traditional stories about lethal raids that had been handed down for generations by word of mouth. Scalise Sugiyama analyzed a cross-cultural sample of war stories from 45 societies and found that the five fitness costs often feature within these story lines. The war stories included tales from various North American Indian tribes, the Eskimo of the Arctic, Aborigine groups of Australia, the San of Southern Africa and certain South American tribal societies.

Based on the fitness costs documented in these stories, Scalise Sugiyama believes that ancestral women may have developed certain strategies to increase their odds of survival and their ability to manage their reproduction in the face of warfare. These include manipulating male behavior, determining whether the enemy’s intent was to kill or capture them, and using defensive and evasive tactics to sidestep being murdered or to escape captivity. Assessing the risk of resistance versus compliance also requires having several sets of knowledge. This includes information about an enemy’s warfare practices and how they treat their captives.

The so-called Stockholm Syndrome, in which hostages bond with their captors, could have ancestral roots, hypothesizes Scalise Sugiyama. It often occurs under conditions of physical confinement or physical, sexual, and/or emotional abuse, which are characteristic of captivity in ancestral forager and forager-horticulturalist groups. This response could have developed as a way to help captives identify and ultimately integrate with enemy groups. This then motivates acceptance of the situation and reduces attempts to resist the captor – which may ultimately increase a woman’s chances of survival.

“Lethal raiding has recurrently imposed fitness costs on women. Female cognitive design bears reexamination in terms of the motivational and decision-making mechanisms that may have evolved in response to them,” says Scalise Sugiyama.

Springer Science+Business Media – Header Image Credit : Rod Waddington

Categories: General

VIDEO: Geldof describes scene in studio

BBC test - Sat, 2014-11-15 15:12
Bob Geldof has been describing the scene inside the studio where stars have been recording the new version of the Band Aid charity single.
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VIDEO: GWR's new trains unveiled in Japan

BBC test - Sat, 2014-11-15 12:37
Great Western Railway's new trains have been unveiled at a ceremony in Japan.
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VIDEO: Fitball: Is it netball, is it football?

BBC test - Sat, 2014-11-15 11:41
A school in Luton introduces a new sport to the curriculum, Fitball, with the aim of making school sport more inclusive.
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VIDEO: Bob Geldof: 'I just feel gratitude'

BBC test - Sat, 2014-11-15 10:37
Stars including Ed Sheeran and One Direction have been arriving in Notting Hill for the recording of the new Band Aid charity single.
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VIDEO: National Lottery marks 20 years

BBC test - Sat, 2014-11-15 09:45
The UK's National Lottery is 20 years old.
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VIDEO: G20: Cameron warns Putin over Ukraine

BBC test - Sat, 2014-11-15 08:44
David Cameron has told the BBC that Russia will face a tough response from the West unless it stops sending troops and tanks to support separatist rebels in Ukraine.
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VIDEO: Cameron warns Putin over Ukraine

BBC test - Sat, 2014-11-15 08:41
David Cameron says Russia will face a tough response from the West unless it stops sending troops and tanks to support separatist rebels in Ukraine.
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