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Ancient DNA Set to Rewrite Human History

Rex Dalton
Nature
Wed, 12 May 2010 18:54 UTC
Discovery that some humans are part-Neanderthal reveals the promise of comparing genomes old and new.

The worlds of ancient and modern DNA exploration have collided in spectacular fashion in the past few months. Last week saw the publication of a long-awaited draft genome of the Neanderthal, an archaic hominin from about 40,000 years ago.[1] Just three months earlier, researchers in Denmark reported the genome of a 4,000-year-old Saqqaq Palaeo-Eskimo[2] that was plucked from the Greenland permafrost and sequenced in China using the latest technology.

Neanderthal
© Nature PHOTOLIBRARYNeanderthals once bred with Homo sapiens.
As researchers compare these ancient genomes with the ever-expanding number from today's humans, they expect to gain insights into human evolution and migration - with more discoveries to come as they decipher DNA from other branches of the human evolutionary tree. "For the first time, ancient and modern genetic research is going hand in hand," says Eske Willerslev, whose team at the University of Copenhagen led the Palaeo-Eskimo sequencing project. "It is really a fantastic time."
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Telescope

Death of a star in 3 dimensions

Dr. Hannelore Hämmerle
Max-Planck-Gesellschaft
Wed, 12 May 2010 11:48 UTC
Image
© MPAThis is a three-dimensional explosion simulation at about 0.5 seconds after core ignited. The bluish, almost transparent surface is the shock front with an average radius of 1900 km.
New computer models show in detail how supernovae obtain their shape

This release is available in German.

Massive stars end their lives in gigantic explosions, so called supernovae, and can become - for a short time - brighter than a whole galaxy, which is made up of billions of stars. Although supernovae have been studied theoretically by computer models for several decades, the physical processes happening during these blasts are so complex that until now astrophysicists could only simulate parts of the process and so far only in one or two dimensions. Researches at the Max Planck Institute for Astrophysics in Garching have now carried out the first fully three-dimensional computer simulations of a core collapse supernova over a timescale of hours after the initiation of the blast. They thus could answer the question of how initial asymmetries, which emerge deep in the dense core during the very early stages of the explosion, fold themselves into inhomogeneities observable during the supernova blast.
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Magnify

Mysterious Mayan ceremonial head found at Tak´alik Ab´aj

Barbara Schieber
Australia's Business and World News
Wed, 12 May 2010 11:36 UTC
Image
© Tak' alik Ab' aj National Project, Ministry of Culture and Sports of Guatemala.
Guatemala - Discovery of an extraordinary offering of a jadeite mosaic miniature ceremonial head underscores the importance and political power at the beginning of Early Classic of the ancient Maya city Tak'alik Ab'aj

Tak'alik Ab'aj is an ancient pre-Hispanic city situated in El Asintal, Department of Retalhuleu at the pacific piedmont of Guatemala. This important long distance trade and cosmopolitan cultural center is transcendent because of its long history which endured 1700 years (800 B.C. - 900 A.D). At its beginnings Tak'alik Ab'aj interacted and participated with the Olmec culture, and at its surmise, was one of the protagonists in the development of the early Maya culture. This particularity in addition to the extraordinary production of sculpture programs during these two important cultural periods, make Tak'alik Ab'aj unique in the history of Mesoamerica.
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Easter Island Discovery Sends Archaeologists Back to Drawing Board


Archaeology News
Wed, 12 May 2010 09:00 UTC
Image
© Unknown
Archaeologists have disproved the fifty-year-old theory underpinning our understanding of how the famous stone statues were moved around Easter Island.

Fieldwork led by researchers at University College London and The University of Manchester, has shown the remote Pacific island's ancient road system was primarily ceremonial and not solely built for transportation of the figures.

A complex network of roads up to 800-years-old crisscross the Island between the hat and statue quarries and the coastal areas.

Laying alongside the roads are dozens of the statues- or moai.

The find will create controversy among the many archaeologists who have dedicated years to finding out exactly how the moai were moved, ever since Norwegian adventurer Thor Heyerdahl first published his theory in 1958.

Heyerdahl and subsequent researchers believed that statues he found lying on their backs and faces near the roads were abandoned during transportation by the ancient Polynesians.
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Radar

'Zombie' satellite runs amok in Earth's orbit

Peter B. de Selding
Christian Science Monitor
Wed, 12 May 2010 00:58 UTC
Galaxy 15
© Newscom/FileIntelsat's Galaxy 15 satellite launched in 2005 with an Ariane 5 rocket in Guyana. The communications satellite stopped responding last month, becoming a 'zombie' satellite that now threatens other spacecraft
The out-of-control communications satellite Galaxy 15 is drifting into orbits occupied by other spacecraft.

An attempt to shut down the electronics payload of the out-of-control communications satellite Galaxy 15 has failed, leaving the satellite - which ceased responding to ground commands last month - still in its uncontrolled "zombiesat" drift toward orbits occupied by other spacecraft, the satellite's fleet operator Intelsat said Tuesday.

Galaxy 15 is closing in on the geostationary orbital slot occupied by another C-band satellite, the AMC-11 spacecraft operated by SES World Skies, and with its stuck-on communications payload will be in a position to cause potentially severe interference with the SES satellite during a two-week period starting around May 23, according to Intelsat and SES estimates.
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Info

Magnetically-Induced Hallucinations Explain Ball Lighting, Say Physicists


The Physics arXiv Blog
Tue, 11 May 2010 00:37 UTC
TMS
© ArXiv.org
Powerful magnetic fields can induce hallucinations in the lab, so why not in the real world, too? Transcranial magnetic stimulation (TMS) is an extraordinary technique pioneered by neuroscientists to explore the workings of the brain. The idea is to place a human in a rapidly changing magnetic field that is powerful enough to induce currents in neurons in the brain. Then sit back and see what happens.

Since TMS was invented in the 1980s, it has become a powerful way of investigating how the brain works. Because the fields can be tightly focused, it is possible to generate currents in very specific areas of the brain to see what they do.

Focus the field in the visual cortex, for example, and the induced eddys cause the subject to 'see' lights that appear as discs and lines. Move the the field within the cortex and the subject sees the lights move too.

All that much is repeatable in the lab using giant superconducting magnets capable of creating fields of as much as 0.5 Tesla inside the brain.

But if this happens in the lab, then why not in the real world too, say Joseph Peer and Alexander Kendl at the University of Innsbruck in Austria. They calculate that the rapidly changing fields associated with repeated lightning strikes are powerful enough to cause a similar phenomenon in humans within 200 metres.
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Heart

Evidence Growing of Air Pollution's Link to Heart Disease, Death


Science Daily
Tue, 11 May 2010 22:39 UTC
The scientific evidence linking air pollution to heart attacks, strokes and cardiovascular death has "substantially strengthened," and people, particularly those at high cardiovascular risk, should limit their exposure, according to an updated American Heart Association scientific statement.

The evidence is strongest for fine particulate matter (PM2.5) having a causal relationship to cardiovascular disease, said the expert panel of authors who updated the association's 2004 initial statement on air pollution, also published in Circulation: Journal of the American Heart Association.

The major source of PM2.5 is fossil fuel combustion from industry, traffic, and power generation. Biomass burning, heating, cooking, indoor activities and forest fires may also be relevant sources, particularly in certain regions.

"Particulate matter appears to directly increase risk by triggering events in susceptible individuals within hours to days of an increased level of exposure, even among those who otherwise may have been healthy for years," said Robert D. Brook, M.D., lead author of the statement, which was written after review of epidemiological, molecular and toxicological studies published during the past six years.
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Space technology revolutionizes archaeology, understanding of Maya

Chad Binette
University of Central Florida
Tue, 11 May 2010 16:32 UTC
Image
© Caracol Archaeological ProjectUniversity of Central Florida researchers led a NASA-funded research project in April 2009 that collected the equivalent of 25 years worth of data in four days. Aboard a Cessna 337, LiDAR (Light Detection and Ranging) equipment bounced laser beams to sensors on the ground, penetrating the thick tree canopy and producing images of the ancient settlement and environmental modifications made by the inhabitants of the Maya city of Caracol. This LiDAR image shows the density of terracing in the Ceiba terminus area
A flyover of Belize's thick jungles has revolutionized archaeology worldwide and vividly illustrated the complex urban centers developed by one of the most-studied ancient civilizations -- the Maya.

University of Central Florida researchers led a NASA-funded research project in April 2009 that collected the equivalent of 25 years worth of data in four days.

Aboard a Cessna 337, LiDAR (Light Detection and Ranging) equipment bounced laser beams to sensors on the ground, penetrating the thick tree canopy and producing images of the ancient settlement and environmental modifications made by the inhabitants of the Maya city of Caracol within 200 square kilometers (77 square miles).
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Pharoah

Church and Nilometer discovered on Egypt's Avenue of Sphinxes

Ann Wuyt
The Independant
Tue, 11 May 2010 16:23 UTC
Image
© Supreme Council of AntiquitiesRestoration works at the Avenue of Sphinxes.
Archaeologists working at the Avenue of Sphinxes in Luxor, Egypt, have uncovered the remains of a fifth century Coptic church and a Nilometer, a structure used to measure the level of the Nile during floods.

According to a statement released by Egypt's Supreme Council of Antiquities (SCA), the remains of the church were found on the second of five sections of the ancient religious path leading to the Karnak temple.
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Meteor

Is Halley's comet an alien interloper?

David Shiga
New Scientist
Tue, 11 May 2010 16:20 UTC
Image
© Royal Observatory, Edinburgh/AAO/SPLStolen from a stellar nursery
Our sun may have stolen the vast majority of its comets from other stars. The theft could explain the puzzling profusion of objects in a huge reservoir surrounding the sun called the Oort cloud.

The Oort cloud is a collection of comets thought to orbit the sun in a roughly spherical halo about 50,000 times as far from the sun as Earth - at the outer edge of the solar system. How did the comets get there? In the standard picture, they formed much closer to the sun, then migrated outward in a two-stage process.

First, the gravity of the giant planets flung them into elongated orbits to form a population called the scattered disc. Objects in the scattered disc come about as close to the sun as Neptune, but venture dozens of times further out, to more than 1000 times the Earth-sun distance. That far from the sun, the gravitational pull of the galaxy becomes significant, so many of the scattered-disc objects get pulled out to populate the Oort cloud.

There is a problem with this picture, however. Simulations have long predicted that this process could only populate the Oort cloud with 10 times as many comets as are currently in the scattered disc, while estimates based on observed comets suggest the ratio is more like 700 to 1.
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