Earth ChangesS


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The Benefits of Stress...in Plants

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© Flickr
Chronic stress in humans has been implicated in heart disease, weight gain, and diabetes, among a host of other health problems. Extreme environments, a source of chronic stress, present a challenge even for the hardiest organisms, and plants are no exception. Yet, some species somehow manage to survive, and even thrive, in stressful conditions.

A recent article by Dr. Yuri Springer in the November issue of the American Journal of Botany finds that certain wild flax plants growing in poor soils have succeeded in balancing the stress in their lives -- these plants are less likely to experience infection from a fungal pathogen. Walking the fine line between the costs associated with surviving under stressful conditions and the benefits that may be derived from growing in an environment with fewer interactions with antagonistic species is a tricky balancing act.

For plants, serpentine soils are one example of an extreme environment. Serpentine soils are those that provide a stressful medium for plant growth, due to features of the soil, such as a rocky texture, low water-holding capacity, high levels of toxic metals, and/or low levels of necessary nutrients.

Cloud Lightning

Ireland facing huge bill for flood damage

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© Eamon WardSome people find the bright side in everything! Cloughleigh-native Shane Millar makes good use of his skim board on the streets of Ennis yesterday.
South and west hardest hit as Army is deployed

Ireland faces a multi-million euro flood damage bill after some of the worst flooding in living memory.

Bus and rail travel was disrupted, motorists were urged to undertake journeys only if absolutely necessary and the Army was called out to help stem rising floodwaters as parts of the South and the West faced the brunt of the atrocious conditions.

Last night, Met Eireann warned of more bad weather to come with more wind and heavy rain. Meteorologists added that next week was looking "every bit as unsettled".

Bizarro Earth

5.1 Earthquake Hits New Zealand

Two earthquakes hit near New Zealand North Island's Palmerston North on Thursday morning. There have been no immediate reports of injury or damage.

The New Zealand Institute of Geological and Nuclear Sciences (GNS Science) said the first tremor of 5.1 magnitude struck at 7:04a.m. (18:04 GMT Wednesday), 10 km south of Palmerston North at a depth of 40 km.

The tremor was felt throughout the North Island.

Bug

Bees Can Learn Differences in Food's Temperature, Study Finds

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© James NiehHoneybees can discriminate between food at different temperatures, researchers have found.
Biologists at UC San Diego have discovered that honeybees can discriminate between food at different temperatures, an ability that may assist bees in locating the warm, sugar-rich nectar or high-protein pollen produced by many flowers.

While other researchers had previously found hints that bees might have the ability to do this, the UCSD biologists provide the first detailed experimental evidence in a paper that will be published in the December 1 issue of the Journal of Experimental Biology.

"We show that honeybees have the ability to associate temperature differences with food," said James Nieh, an associate professor of biology who headed the study. "This information may help guide bees looking for food by allowing them to distinguish which bees are returning to the hive with the highest quality of food."

Bug

The Evolution of Bat Migration

Most people know the term of "migrating bird" but "migrating bat" is not very established. However, some bat species migrate every year long or short distances. Whereas birds migrate to exploit seasonal food resources, the majority of bats migrate with the intention to find better hibernating conditions.

In Europe about 30 percent and in North America around 45 percent of bird species migrate; the migration of bats however is a rather rare phenomenon. Only about three percent of the approximately 1,000 bat species migrate, of those less than 0.016 percent migrate further than 1,000 kilometers. The vast majority of bats of the temperate zone hibernate during winter, as a result of the food shortage at this time.

Together, researchers of the University of Princeton in the U.S. and the Max-Planck Institute for Ornithology have analyzed the genealogical tree of bats on the basis of their migratory behavior. They are confining themselves to only the family of the Vespertilionidae, also called the vespertilionid bats, which includes 316 species or about a third of all bat species. Of about 32 migrating bat species, 23 are part of this family. Eleven of those migrate over long distances longer than 1,000 kilometers. The remaining twelve only fly short distances that vary between 100 and 1,000 kilometers.

Frog

Why Israeli Rodents are More Cautious than Jordanian Ones?

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© iStockphoto/Johannes NorpothIsraeli gerbils are more cautious than their Jordanian friends.
A series of studies carried out at the University of Haifa have found that rodent, reptile and ant lion species behave differently on either side of the Israel-Jordan border. "The border line, which is only a demarcation on the map, cannot contain these species, but the line does restrict humans and their diverse impact on nature," says Dr. Uri Shanas.

Is a border line simply a virtual line appearing on the map? If so, why is it that Israeli rodents are more cautious than Jordanian rodents? Why is it that there are more ant lions in Israel than in Jordan? And how come there are more reptile species in Jordan than in Israel? A series of new studies at the University of Haifa's Department of Environmental and Evolutionary Biology and the University of Haifa-Oranim's Faculty of Sciences and Science Education are exploring the answers.

"The boundary is only a virtual marking that appears on the map and is not capable of keeping these species from crossing the border between Israel and Jordan; but the line does stop humans from crossing it and thereby contains their different impact on nature," says Dr. Uri Shanas, a participant in the research.

The series of studies, which have been carried out in cooperation with Jordanian researchers, has examined a variety of reptile, mammal, beetle, spider and ant lion species on either side of the border in the Arava region. The Israeli team includes Dr. Shanas and research students Idan Shapira and Shacham Mitler, who set out to reveal whether the border -- unknown to the species -- could affect differences between them and their numbers on either side of the frontier, even though they share identical climate conditions.

Hourglass

US: Bats - The New Canary In The Coal Mine?

Bat
© Unknown
You may think bats are scary, but what's truly terrifying is the mysterious fungus that's decimating the bat population, according to an article by Stacy Chase in last Sunday's Boston Globe:
At least 1 million bats in the past three years have been wiped out by a puzzling, widespread disease dubbed "white-nose syndrome" in what preeminent US scientists are calling the most precipitous decline of North American wildlife in human history. If it isn't slowed or stopped, they believe bats will continue disappearing from the landscape in huge numbers and that entire species could become extinct within a decade.
This would have drastic repercussions for the rest of us. As Tim King, a conservation geneticist with the US Geological Survey in West Virginia, told Chase, "We're at the vanguard of an environmental catastrophe."

Attention

US: What's killing the bats?

At least 1 million have died in the past three years from a mysterious disease, posing serious questions for our environment. But one Boston University biologist is leading the hunt for answers.

Big brown bats
© Unknown
Thomas Kunz emerges from Aeolus cave in East Dorset, Vermont, with a half-dozen metal ID bands -- smaller than SpaghettiOs -- cupped in the palm of his latex-gloved hand. They're tiny emblems of death, having once been affixed to the forearms of little brown bats.

The renowned bat biologist from Boston University, who bears a passing resemblance to Harrison Ford, minutes earlier had recovered the bands while trudging, like a real-life Indiana Jones, through a slippery mud-like ooze of rotting bat carcasses, liquefied internal organs, toothpick-sized bones, piles of guano, and a strange white fungus on the cave floor.

If bats had come out of hell, it couldn't have been worse than this.

"What we saw was bat soup. There were a lot of bones of wings and skulls and emulsified bodies," Kunz says. "There were dead bats -- decomposing bats -- hanging from the walls of the cave.

"My heart sunk," he says, noting some of the bands bore his initials, THK. "It was as if I had lost family members."

It's late August, when bats are in their swarming phase, and the 71-year-old Kunz and two fellow biologists have trekked, at night, in hard rain, with heavy gear, 2,520 feet up the rugged Taconic Mountains to Aeolus -- the largest bat hibernaculum in the Northeast -- to bleed live bats and collect samples for researchers leading the hunt for clues into the cause of mysterious bat deaths like these.

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Penguin DNA Evolving Faster Than Thought

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© 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.

Bug

Orphan Army Ants Join Nearby Colonies

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© 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.