|University of California - Los Angeles
Nov. 14, 2013 — Wolves likely were domesticated by European hunter-gatherers more than 18,000 years ago and gradually evolved into dogs that became household pets, UCLA life scientists report.
"We found that instead of recent wolves being closest to domestic dogs, ancient European wolves were directly related to them," said Robert Wayne, a professor of ecology and evolutionary biology in UCLA's College of Letters and Science and senior author of the research. "This brings the genetic record into agreement with the archaeological record. Europe is where the oldest dogs are found."
The UCLA researchers' genetic analysis is published Nov. 15 in the journal Science and featured on the journal's cover.
In related research last May, Wayne and his colleagues reported at the Biology of Genomes meeting in New York the results of their comparison of the complete nuclear genomes of three recent wolf breeds (from the Middle East, East Asia and Europe), two ancient dog breeds and the boxer dog breed.
No Peak in Sight for Evolving Bacteria
|Michigan State University
Nov. 14, 2013 — There's no peak in sight -- fitness peak, that is -- for the bacteria in Richard Lenski's Michigan State University lab.
Lenski, MSU Hannah Distinguished Professor of Microbiology and Molecular Genetics, has been running his evolutionary bacteria experiment for 25 years, generating more than 50,000 generations. In a paper published in the current issue of Science, Michael Wiser, lead author and MSU graduate student in Lenski's lab, compares it to hiking.
"When hiking, it's easy to start climbing toward what seems to be a peak, only to discover that the real peak is far off in the distance," Wiser said. "Now imagine you've been climbing for 25 years, and you're still nowhere near the peak."
Only the peaks aren't mountains. They are what biologists call fitness peaks -- when a population finds just the right set of mutations, so it can't get any better. Any new mutation that comes along will send things downhill.
Better Batteries Through Biology? Modified Viruses Boost Battery Performance
|Massachusetts Institute of Technology
Nov. 13, 2013 — MIT researchers have found a way to boost lithium-air battery performance, with the help of modified viruses.
Lithium-air batteries have become a hot research area in recent years: They hold the promise of drastically increasing power per battery weight, which could lead, for example, to electric cars with a much greater driving range. But bringing that promise to reality has faced a number of challenges, including the need to develop better, more durable materials for the batteries' electrodes and improving the number of charging-discharging cycles the batteries can withstand.
Now, MIT researchers have found that adding genetically modified viruses to the production of nanowires -- wires that are about the width of a red blood cell, and which can serve as one of a battery's electrodes -- could help solve some of these problems.
Interactive Infographic: What Would A Hyperloop Nation Look Like?
|If Elon Musk's mass-transit plan came to fruition, this is what it would mean for travel.
By Katie Peek
In August, Silicon Valley darling Elon Musk—CEO of SpaceX and Tesla Motors—unveiled his concept for the Hyperloop, a high-speed system of 28-person pods that would shoot through low-pressure tubes on air bearings. Musk’s published proposal calls for the Hyperloop to link San Francisco and Los Angeles; pods would blast down the I-5 corridor at 760 mph, reducing the journey from five and a half hours by car to just 35 minutes.
Musk envisions the system connecting cities less than 900 miles apart—beyond that, he writes, “I suspect supersonic air travel ends up being faster and cheaper.” Using the 900-mile limit, we calculated other areas that could be connected by the Hyperloop. Theoretically, pairs such as Memphis and Chicago or Salt Lake City and Seattle could bridge the distance of a morning commute, blending economies and cultures, and reshaping the continent.
Elon Musk estimates that a Hyperloop from San Francisco to Los Angeles will cost six billion dollars, one tenth the proposed cost of California’s high-speed rail project. Transportation experts, however, say he is underestimating the price tag.
A Hyperloop could bridge borders, making San Antonio and Mexico City suburbs of each other, with a journey of 75 minutes. Farther north, New York and Montreal would be only 35 minutes apart.
Evidence of 3.5-Billion-Year-Old Bacterial Ecosystems Found in Australia
Nov. 12, 2013 — Reconstructing the rise of life during the period of Earth's history when it first evolved is challenging. Earth's oldest sedimentary rocks are not only rare, but also almost always altered by hydrothermal and tectonic activity. A new study from a team including Carnegie's Nora Noffke, a visiting investigator, and Robert Hazen revealed the well-preserved remnants of a complex ecosystem in a nearly 3.5 billion-year-old sedimentary rock sequence in Australia.
Their work is published in Astrobiology.
The Pilbara district of Western Australia constitutes one of the famous geological regions that allow insight into the early evolution of life. Mound-like deposits created by ancient photosynthetic bacteria, called stromatolites, and microfossils of bacteria have been described by scientists in detail. However, a phenomenon called microbially induced sedimentary structures, or MISS, had not previously been seen in this region. These structures are formed from mats of microbial material, much like mats seen today on stagnant waters or in coastal flats.
How Climate Change and Plate Tectonics Shaped Human Evolution
|A new study links the emergence of new hominin species, expanding brain capacity and early human migration with the appearance of deep freshwater lakes
By Mark Maslin and The Conversation
It should not be a surprise that East Africa was a hotbed of evolution, because over the last five million years everything about the landscape has changed.
The extraordinary forces of plate tectonics and a changing climate have transformed East Africa from a relatively flat, forested region to a mountainous fragmented landscape dominated by the rapid appearance and disappearance of huge, deep-water lakes. And from this highly variable landscape emerged an ape smart enough to question its own existence.
A cradle rocked by tectonics
Twenty million years ago the Indian and Asian continental plates clashed and pushed up the massive Tibetan plateau. In summer this plateau acts as a huge heat engine, absorbing solar energy which it transfers to the atmosphere, causing immense convection currents. With all this hot air rising, air is sucked in from all round, including moist air from the Indian Ocean that produces intense South East Asian monsoons.
Do Their Teenaged Brains Make Adolescents More Likely To Commit Crimes?
|Teens have more trouble controlling their impulses in emotionally charged situations.
By Shaunacy Ferro
Teenagers aren’t known for making extraordinarily good decisions. They’re stereotypically known to do somewhat idiotic things, like, for instance, drunkenly stealing a llama and taking it for a tram ride. They have a tendency to do impulsive, risky things—one study puts teens’ risk of getting themselves killed at 200 percent greater compared to children.
Why are teens so prone to risk-taking compared to either their childhood or adult selves? Younger kids don’t have the same propensity for risk-taking, though their brains are also developing. As a pair of researchers told a meeting of the Society for Neuroscience this week, it might be that teenagers’ brains have to work harder to keep their impulses in check, making them react more impulsively in threatening situations.
Neuroscientists Kristina Caudle and BJ Casey of Weill Cornell Medical College discussed their work on the teenage brain and self-control. In emotionally cool situations, “the teen appears to be capable of acting rationally and making optimal decisions,” as they wrote in an April 2013 paper. However, when things get emotional, many teenagers have more difficulty with self-control.
Some Danish Advice on the Trans-Fat Ban
|The U.S. is considering a limit on the artery clogger similar to one Denmark instituted a decade ago. How did the ban impact that country?
By Dina Fine Maron
When the U.S. Food and Drug Administration proposed to eliminate artery-clogging fats from all foodstuffs last week, they could look across the Atlantic Ocean at one recipe for success. Denmark placed tight restrictions on its own partially hydrogenated oils—the main source of trans fats—a decade ago.
In fact, U.S. action follows in the footsteps of a cadre of nations that have sought to limit trans fat intake already. And their results and playbook could provide a glimpse of the future in the U.S. In 2003 Denmark green-lighted legislation that limited the same substance in its food. Their law did not ban the substance, but it did force manufacturers to limit its use—any food could only have up to 2 percent of its fat made of trans fat, substantially shrinking the presence. Later, Austria, Switzerland, Iceland and Sweden followed suit. And parts of the U.S., including New York City and California, independently took action in recent years to pass legislative limits on trans fat in the food served in restaurants.
Jupiter Mystery Solved: Why the Giant Planet's Mysterious Great Red Spot Has Not Disappeared
|American Physical Society's Division of Fluid Dynamics
Nov. 14, 2013 — Jupiter's Great Red Spot is one of the solar system's most mysterious landmarks. Based on what scientists understand about fluid dynamics, this massive storm -- which is big enough to engulf Earth two or three times over -- should have disappeared centuries ago.
Pedram Hassanzadeh, a postdoctoral fellow at Harvard University, and Philip Marcus, a professor of fluid dynamics at the University of California, Berkeley, think they can explain why. Their work, which Hassanzadeh will present at the annual meeting of the American Physical Society's Division of Fluid Dynamics in Pittsburgh on November 25, also provides insight into persistent ocean eddies and vortices that contribute to star and planet formation.
"Based on current theories, the Great Red Spot should have disappeared after several decades. Instead, it has been there for hundreds of years," said Hassanzadeh, who is a post-doctoral fellow at Harvard's Center for the Environment and the Department of Earth and Planetary Sciences.
Many processes dissipate vortices like the Red Spot, Hassanzadeh explained. The turbulence and waves in and around the Red Spot sap the energy of its winds. The vortex also loses energy by radiating heat. Finally, the Red Spot sits between two strong jet streams that flow in opposite directions and may slow down its spinning.
NASA Probe to Track Mars’s Missing Atmosphere
|Where did the Red Planet’s carbon dioxide blanket and liquid surface water go? NASA’s Maven mission will launch next week to investigate
By Clara Moskowitz
Lest we forget, getting to Mars is hard. Two thirds of the missions launched to the Red Planet never made it, and only the U.S., European Space Agency (ESA) and the Soviet Union have succeeded thus far. India is vying to join their ranks with the recently launched Mars Orbiter Mission, and NASA hopes to continue its winning streak next week, when it lofts the Maven spacecraft on a journey to trace the mystery of Mars’s missing atmosphere.
If it succeeds, Maven will join two other NASA orbiters (the Mars Reconnaissance Orbiter and Mars Odyssey) as well as ESA’s Mars Express, in circling the Red Planet, and will help relay messages from the U.S. space agency’s current and future rovers on the ground (Curiosity and Opportunity, and another rover planned to launch in 2020) back to Earth. This vital job was the main reason that NASA spared Maven when work on all other prelaunch NASA missions halted during the U.S. government shutdown last month. If technicians had not continued preparing the probe, it might have missed its three-week launch window toward Mars. “As a program, we recognized a risk to the agency of not only missing the science that [Maven] was poised to do, but also of not having a long-lived enough asset” to continue relaying communications from Mars rovers back to Earth, Lisa May, Maven program executive at NASA’s Headquarters, said during a press conference October 28 previewing the mission.
Where Someone Drowns Determines Their Chance of Survival
|St. Michael's Hospital
Nov. 14, 2013 — Two new research studies show that location is the most important factor in determining drowning survival.
"Ontarians from rural areas are almost three times more likely to die of drowning than urban residents," said Dr. Stephen Hwang of the Centre for Research on Inner City Health at St. Michael's Hospital in Toronto.
Rural residents' increased access to open water and decreased access to swimming lessons were some of the factors that the study's authors felt might account for the difference between rural and urban drowning rates.
Another study, published today in Canadian Journal of Emergency Medicine, showed that most drownings occur in public places -- such as on open water, recreation centres or parks.