Science & TechnologyS

Igloo

Prehistoric Dog Domestication Derailed by Ice Age

Siberian
© Getty ImagesThe 33,000-year-old remains of an animal in Siberia suggest it was partly domesticated. Its bones suggest it resembled the modern Samoyed dog, shown here.

Some dogs were domesticated by at least 33,000 years ago, but these canines did not generate descendants that survived past the Ice Age, suggests a new PLoS ONE study.

The theory, based on analysis of a 33,000-year-old animal that may have been a partly domesticated dog, explains why the remains of possible prehistoric dogs date to such early periods, and yet all modern dogs appear to be descended from ancestors that lived at the end of the Ice Age 17,000-14,000 years ago.

The ancient animal identified as being a partly domesticated dog was found in Razboinichya Cave in the Altai Mountains of southern Siberia.

"The Razboinichya dog find demonstrates that the right wolf/human conditions suitable for getting domestication started were present at least 33,000 years ago," co-author Susan Crockford told Discovery News. "However, such conditions would have had to be present continuously -- stable -- for many wolf generations, perhaps 20 over about 40 years for the domestication process to generate a true dog."

"It appears that such stable conditions were not present until after the Ice Age, sometime after 19,000 years ago," added Crockford, a researcher at Pacific Identifications Inc. and author of the book Rhythms of Life. "Even after the Ice Age, domestication of wolves could have got started at several different times and places, and still failed because the conditions were not continuous enough for the changes to become permanent."

Info

'Unexpected' Source of Sea Level Rise Found

Glacier
© Robert Hatfield'Where were you 100,000 years ago?' Scientist Anders Carlson eyes a glacier in icy Greenland, one of the suspects in the case of prehistoric sea level rise.

In the whodunit-style search for the culprit behind drastic sea level rise many thousands of years ago, new research may have cleared one falsely accused party - but, like any good thriller, the story of the exoneration brings with it an ominous twist, and one that has implications for life on Earth today.

The last time portions of the Earth were as warm as they are today was around 100,000 years ago. Over a span of 12 toasty millennia known as the Last Interglacial Period (128,000 to 116,000 years ago), summertime temperatures in the Northern Hemisphere were as much as 9 degrees Fahrenheit (5 degrees Celsius) hotter, and worldwide, sea levels were roughly 21 feet (6.5 meters) higher than they are now.

"The only ways of doing that are thermal expansion of the oceans, and melting of ice," said Anders Carlson, an assistant professor in the department of geosciences at the University of Wisconsin and author of a paper on the ancient sea level rise published today in the journal Science.

"Seas rise over millions of years, driven by the movements of crusts, the building of mountains," Carlson told OurAmazingPlanet, "but this only occurred over a few thousand years and that's too short a time to be explained by tectonics."

Question

Masses of Humans May Have Sent Neanderthals Packing

Neanderthal
© Mauro CutronaAn artist's depiction of a Neanderthal. New research is suggesting that increases in the human population, possibly up to 10-fold, in southwestern France might have pushed the Neanderthals out of the area.

Territory wars, superior brain power, better tools, changing climate - many reasons have been suggested as to how humans won out over Neanderthals in Europe, but new research is suggesting that pure population power may have been the key.

"All kinds of theories have been put forward in the past, but what we've wanted to do, is to make some kind of estimate of the relative numbers of late Neanderthals compared to modern humans," study researcher Paul Mellars, of Cambridge University in the United Kingdom, told LiveScience. "We suspected modern humans came in much greater population numbers, the Neanderthals were just swamped by much larger numbers."

From examining the sites inhabited by humans and Neanderthals in what is now southern France, Mellars found that humans eventually outnumbered the Neanderthals by about 10 to one. "Nobody has ever analyzed the data, this is the first time it's been analyzed," Mellars said. "It staggered me when I discovered the scale of the contrast."

While researchers not involved in the study think the idea is credible, they point out that population increases may not have been the only factor involved in the Neanderthals' demise; in addition, the study only provides evidence for the die-out in France, leaving the question of how other Neanderthals were wiped out open.

Info

Holy Talking Plant! Flower Communicates with Bats

Bat and Plants
© Ralph Mangelsdorff and Ralph SimonThis photo montage shows the Cuban nectar feeding bat Monophyllus beside the vine that scientists discovers attracts bats by producing an "echo beacon" with a special leaf. That sonar-reflecting leaf stands upright above the ring of flowers. The cup-like structures that hold the nectar hang below.
Just as some flowers use bright colors to attract insect pollinators, other plants may use sound to lure in nectar-eating bats.

One rain-forest vine has a dish-shaped leaf located above a cluster of flowers that appears to help bats find them (and the plant's tasty nectar) by reflecting back the calls the flying mammals send out, new research indicates.


While there is other evidence that plants use bats' sonar systems to attract them, this is the first time scientists have shown that a plant can produce an "echo beacon" that cuts through sonic clutter of reflected echoes, and that this signal can cut a bat's search time for food in half, according to the researchers, led by Ralph Simon, a research fellow at the University of Ulm in Germany.

Magic Wand

Dolphins' 'remarkable' recovery from injury offers important insights for human healing

Image
© Unknown
Georgetown scientist teams up with dolphin experts to explore the sea animals' 'mysterious' wound healing abilities.

A Georgetown University Medical Center (GUMC) scientist who has previously discovered antimicrobial compounds in the skin of frogs and in the dogfish shark has now turned his attention to the remarkable wound healing abilities of dolphins.

A dolphin's ability to heal quickly from a shark bite with apparent indifference to pain, resistance to infection, hemorrhage protection, and near-restoration of normal body contour might provide insights for the care of human injuries, says Michael Zasloff, M.D., Ph.D.

For a "Letter" published today in the Journal of Investigative Dermatology, Zasloff, an adjunct professor at GUMC and former Dean of Research, interviewed dolphin handlers and marine biologists from around the world, and reviewed the limited literature available about dolphin healing to offer some new observations about what he calls the "remarkable" and "mysterious" ability of dolphins to heal.

"Much about the dolphin's healing process remains unreported and poorly documented," says Zasloff. "How does the dolphin not bleed to death after a shark bite? How is it that dolphins appear not to suffer significant pain? What prevents infection of a significant injury? And how can a deep, gaping wound heal in such a way that the animal's body contour is restored? Comparable injuries in humans would be fatal. "

Sun

New NASA Data Blow Gaping Hole In Global Warming Alarmism

satellite view of ice
© Image by AFP/Getty Images via @daylife
NASA satellite data from the years 2000 through 2011 show the Earth's atmosphere is allowing far more heat to be released into space than alarmist computer models have predicted, reports a new study in the peer-reviewed science journal Remote Sensing. The study indicates far less future global warming will occur than United Nations computer models have predicted, and supports prior studies indicating increases in atmospheric carbon dioxide trap far less heat than alarmists have claimed.

Study co-author Dr. Roy Spencer, a principal research scientist at the University of Alabama in Huntsville and U.S. Science Team Leader for the Advanced Microwave Scanning Radiometer flying on NASA's Aqua satellite, reports that real-world data from NASA's Terra satellite contradict multiple assumptions fed into alarmist computer models.

"The satellite observations suggest there is much more energy lost to space during and after warming than the climate models show," Spencer said in a July 26 University of Alabama press release. "There is a huge discrepancy between the data and the forecasts that is especially big over the oceans."

Bad Guys

South Korean scientists create glowing dog: report

South Korean scientists said on Wednesday they have created a glowing dog using a cloning technique that could help find cures for human diseases such as Alzheimer's and Parkinson's, Yonhap news agency reported.

A research team from Seoul National University (SNU) said the genetically modified female beagle, named Tegon and born in 2009, has been found to glow fluorescent green under ultraviolet light if given a doxycycline antibiotic, the report said.

Meteor

Space scope spies soggy, stupendous Saturnian doughnut

Incontinent moon squirts wetly onto ringed giant

satmoon
© The Register
The European Space Agency's Herschel Space Observatory has discovered just where the water in Saturn's upper atmosphere comes from: a giant aqueous doughnut surrounding the planet, formed by H2O hosing from the moon Enceladus.

NASA's Cassini spacecraft previously spied the water plumes of Enceladus (see pic*), but until now scientists hadn't made the connection between these and Saturnian atmospheric water, first spotted in 1997 by the ESA's Infrared Space Observatory.

In fact, Enceladus's outpourings - estimated at 250kg per second - feed a massive torus which measures "more than 10 times the radius of Saturn", but is just one Saturn-radius thick. ESA explains: "Enceladus orbits the planet at a distance of about four Saturn radii, replenishing the torus with its jets of water."

The doughnut previously went undetected because its water vapour is transparent to visible light, but not to the infrared wavelengths Herschel can sniff.

Beaker

Mitochondria share an ancestor with SAR11, a globally significant marine microbe

Mitochondria2 SAR11
© UnknownMarine bacteria called SAR11
A recent study by researchers at the University of Hawaii, Manoa, and the Oregon State University provides strong evidence that mitochondria share a common evolutionary ancestor with a lineage of marine bacteria known as SAR11, arguably the most abundant group of microorganisms on Earth.

Billions of years ago, an astounding evolutionary event occurred: certain bacteria became obliged to live inside other cells, thus starting a chain of events that resulted in what is now the mitochondria, an organelle found in all eukaryotic cells.

A recent study by researchers at the University of Hawaii - Manoa (UHM) and the Oregon State University (OSU) provides strong evidence that mitochondria share a common evolutionary ancestor with a lineage of marine bacteria known as SAR11, arguably the most abundant group of microorganisms on Earth.

"This is a very exciting discovery," says Michael Rappe, Associate Researcher at the Hawaii Institute of Marine Biology in the School of Ocean and Earth Science and Technology (SOEST) at UHM. "The results that we present make sense in a lot of ways: the physiology of SAR11 makes them more apt to be dependent on other organisms, and based on the contemporary abundance of SAR11 in the global ocean, the ancestral lineage may have also been abundant in the ancient ocean, increasing encounters between this bacterial lineage with the host of the original symbiosis event."

Telescope

A Dying Star's Last Gasps

Image
© Gemini Observatory/AURAThe elegant beauty of this planetary nebula was discovered by an amateur astronomer and captured by the Gemini Observatory.
The image above depicts a recent discovery of a dying star's last gasps, an observation made by a team comprised of amateur and professional astronomers working together. Austrian amateur astronomer Matthias Kronberger and his team made the discovery of the nebula - shells of gas thrown out by some stars near the end of their lives - using the National Science Foundation-supported Gemini Observatory.