Earth ChangesS


Penguin DNA Evolving Faster Than Thought

© D. DenverThe rate at which changes happen in the DNA of Adélie penguins (one shown here with chicks) has been faster than scientists had thought, a new study suggests.
Comparing the DNA in modern birds to that in ancient generations shows molecular evolution can happen at varying rates

The evolutionary march of the penguins happened in double time, according to new genetic calculations.

A study of DNA from ancient and modern Adélie penguins suggests that scientists may have miscalculated the rates at which genetic clocks tick off evolutionary time in other species as well. A team of researchers collected mitochondrial DNA from penguins currently living in rookeries in Antarctica and from bones of penguins that had lived in the same spot as long as 44,000 years ago. Analysis of the DNA reveals that the penguins are evolving on a molecular scale two to six times faster than standard calculations indicated, the team reports in the November Trends in Genetics.

Mitochondria are small structures that generate power inside cells. The organelles were once free-living bacteria and have kept their own circle of DNA, which encodes many of the proteins needed for power production. The function of mitochondria is so crucial to the cell that any changes to mitochondrial genes are likely to throw a wrench into a cell's energy-generating capabilities. As a result, the mitochondrial DNA has evolved slowly. Scientists can use the number of changes in mitochondrial DNA between different species to calculate a molecular rate of evolution and estimate how long ago the species shared a common ancestor.


Orphan Army Ants Join Nearby Colonies

© Daniel Kronauer/Harvard UniversityArmy ants are group predators that overwhelm large arthropods and other social insect colonies. Here, a raiding swarm of Dorylus molestus is attacking a grasshopper at Mt Kenya.
Colonies of army ants, whose long columns and marauding habits are the stuff of natural-history legend, are usually antagonistic to each other, attacking soldiers from rival colonies in border disputes that keep the colonies separate. But new work by a researcher at the Harvard Museum of Comparative Zoology and colleagues at the University of Copenhagen shows that in some cases the colonies can be cooperative instead of combative.

In those cases, when an army ant colony loses its queen, its workers are absorbed, not killed, by neighboring colonies, and within days are treated as part of the family.

The research, conducted in an ant-rich area on the slopes of Mount Kenya, is detailed in the journal Proceedings of the Royal Society B.

Army ant colonies are dominated by a single, large queen who produces the eggs that give rise to all of the colony's individuals, which can number millions of workers. When she dies, colonies quickly disappear, raising the question of what happens to the many individuals.

Bizarro Earth

Earthquake Magnitude 6.6 - Queen Charlotte Islands Region

Tuesday, November 17, 2009 at 15:30:46 UTC

Tuesday, November 17, 2009 at 07:30:46 AM at epicenter

52.151°N, 131.378°W

11.6 km (7.2 miles)

250 km (155 miles) SSW (197°) from Prince Rupert, BC, Canada

315 km (195 miles) WNW (303°) from Port Hardy, BC, Canada

331 km (206 miles) S (178°) from Metlakatla, AK

662 km (411 miles) WNW (302°) from Vancouver, British Columbia, Canada


It was the Sun wot done it - Or was it?

A sharp drop in solar activity could soon tell us how much mankind and the Sun are responsible for warming the planet

Like it or not, it will soon be time to start placing bets for a white Christmas. If most climatologists are to be believed you are almost certainly throwing your money away.

The onward march of global warming is consigning such traditional Christmas card scenes to history. No more deep and crisp and even winters for Britain, replaced instead by damp and slush and stormy.

But, if a small group of maverick scientists are right, the chances of Yuletide snow may rise dramatically over the coming decades.

The difference of opinion hinges on what role - if any - the Sun plays in climate change. The vast majority of climate scientists maintain that the solar influence is limited or even negligible, and it is the unsustainable growth of industrialised nations that is driving the climate into chaos. The mavericks contend that the Sun's activity dwarfs the human contribution, and that there is nothing we can do except wait for the Sun to change.


Goat Lived Like a Reptile - A First

© Jordi Nieva The prehistoric goat Myotragus, seen here in an artist's reconstruction at the CosmoCaixa museum in Barcelona, lived on what is now the Spanish island of Majorca.
A prehistoric goat survived for millennia on a resource-poor island by living like a reptile - changing its growth rate and metabolism to match the available food supply, according to a new study of the animal's bones.

The discovery marks the first time scientists have seen this cold-blooded survival strategy in mammals.

The surprising skill likely allowed the goats to endure potentially fatal periods of scarcity on what is now the Spanish island of Majorca.

But the technique, developed when the goats had no major natural enemies, came with costs that seem to have made the now extinct goats unable to survive the arrival of skilled predators - humans - some 3,000 years ago.

The goats' energy-saving adaptations made the animals small and slow, noted study co-author Meike Köhler, a paleobiologist at the Autonomous University of Barcelona, Spain.

Bizarro Earth

Volatile Gas Could Turn Rwandan Lake Into a Freshwater Time Bomb

© iStockphoto/Yves GrauLake Kivu on Rwandan side
A dangerous level of carbon dioxide and methane gas haunts Lake Kivu, the freshwater lake system bordering Rwanda and the Republic of Congo.

Scientists can't say for sure if the volatile mixture at the bottom of the lake will remain still for another 1,000 years or someday explode without warning. In a region prone to volcanic and seismic activity, the fragility of Lake Kivu is a serious matter. Compounding the precarious situation is the presence of approximately 2 million people, many of them refugees, living along the north end of the lake.

An international group of researchers will meet Jan. 13-15 in Gisenyi, Rwanda, to grapple with the problem of Lake Kivu. A grant from the National Science Foundation won by Rochester Institute of Technology will fund the travel and lodging for 18 scientists from the United States to attend the three-day workshop. Anthony Vodacek, conference organizer and associate professor at RIT's Chester F. Carlson Center for Imaging Science, is working closely with the Rwandan Ministry of Education to organize the meeting.

Bizarro Earth

US: Earthquake Magnitude 3.6 Near Palomar Observatory

A magnitude 3.6 earthquake struck northeast of San Diego Monday, according to a preliminary report from the U.S. Geological Survey.

The earthquake struck at 5:54 a.m. about 13 miles east-northeast of the Palomar Observatory and 53 miles north-northeast of San Diego, according to the computer-generated report.

Bizarro Earth

US: Earthquake Magnitude 4.6 - Southern California

Monday, November 16, 2009 at 21:21:30 UTC

Monday, November 16, 2009 at 01:21:30 PM at epicenter

35.549°N, 117.274°W

2 km (1.2 miles)

26 km (16 miles) SSE (158°) from Searles Valley, CA

26 km (16 miles) SSE (160°) from Trona, CA

37 km (23 miles) ESE (102°) from Ridgecrest, CA

188 km (117 miles) NNE (28°) from Los Angeles Civic Center, CA


Jellyfish Swarm Northward in Warming World

© AP Photo/Junji KurokawaA giant jellyfish drifting off Kokonogi in western Japan.
A blood-orange blob the size of a small refrigerator emerged from the dark waters, its venomous tentacles trapped in a fishing net. Within minutes, hundreds more were being hauled up, a pulsating mass crowding out the catch of mackerel and sea bass.

The fishermen leaned into the nets, grunting and grumbling as they tossed the translucent jellyfish back into the bay, giants weighing up to 200 kilograms (450 pounds), marine invaders that are putting the men's livelihoods at risk.

The venom of the Nomura, the world's largest jellyfish, a creature up to 2 meters (6 feet) in diameter, can ruin a whole day's catch by tainting or killing fish stung when ensnared with them in the maze of nets here in northwest Japan's Wakasa Bay.

"Some fishermen have just stopped fishing," said Taiichiro Hamano, 67. "When you pull in the nets and see jellyfish, you get depressed."


Birds Lose Color Vision in Twilight

© iStockphotoHeron at sunset
Research at the Lund University Vision Group can now show that the color vision of birds stops working considerably earlier in the course of the day than was previously believed, in fact, in the twilight. Birds need between 5 and 20 times as much light as humans to see colors.

It has long been known that birds have highly developed color vision that vastly surpasses that of humans. Birds see both more colors and ultraviolet light. However, it was not known what amount of light is necessary for birds to see colors, which has limited the validity of all research on this color vision to bright sunlight only.

"Using behavioral experiments we can now demonstrate that birds lose their color vision in the twilight and show just how much light is needed for birds to be able to interpret color signals," says Olle Lind, a doctoral candidate at the Department of Cell and Organism Biology.