Earth | Page 714 | Science Codex

Risk of interbreeding due to climate change lower than expected

One of the questions raised by climate change has been whether it could cause more species of animals to interbreed. Two species of flying squirrel have already produced mixed offspring because of climate change, and there have been reports of a hybrid polar bear and grizzly bear cub (known as a grolar bear, or a pizzly).

"Climate change is causing species' ranges to shift, and that could bring a lot of closely related species into contact," said Meade Krosby, a research scientist in the University of Washington's Climate Impacts Group.

Grey squirrels are quick learners

They may be viewed by some as an invasive species or a commonplace pest of public parks, but a new study from the University of Exeter has shown that grey squirrels are actually quick learners capable of adapting tactics to improve efficiency and reap the best rewards.

To test the animals' intelligence and mental flexibility researchers invented a task involving a box with 12 sunken wells, four of which were hollow. Of the four, two contained hidden hazelnuts.

'Bee soup' could help understand declines and test remedies

It may sound counter-intuitive, but crushing up bees into a 'DNA soup' could help conservationists understand why declines happen periodically. Collecting wild bees, extracting their DNA, and directly reading the DNA of the resultant 'soup' could finally make large-scale bee monitoring programs feasible. This would allow conservationists to detect where and when bee species are being lost, and whether conservation interventions are working.

Environmental attorneys and an oceanographer want EPA to declare CO2 a "toxic substance" like asbestos

Without carbon dioxide, life as we know it on earth would end in sudden, spectacular fashion - but too much of anything can be a bad thing, and that goes for vegan food or a key component in photosynthesis like CO2.

Lawyers at the Center for Biological Diversity and oceanographer Dr. Donn Viviani have petitioned the Obama administration to regulate carbon dioxide under the federal Toxic Substances Control Act.

Early exposure to cat urine makes mice less likely to escape from cats

Mice that are exposed to the powerful smell of cat urine early in life do not escape from cats later in life. Researchers at the A. N. Severtsov Institute of Ecology and Evolution, Russia, have discovered that mice that smell cat urine early in life, do not avoid the same odour, and therefore do not escape from their feline predators, later in life.

Climate change put mussels off the menu?

Climate change models predict that sea temperatures will rise significantly, including in the tropics. In these areas, rainfall is also predicted to increase, reducing the salt concentration of the surface layer of the sea. Together, these changes would dramatically affect the microscopic communities of bacteria and plankton that inhabit the oceans, impacting species higher up the food chain. Worryingly, future conditions may favour disease-causing bacteria and plankton species which produce toxins, such as the lethal PST (paralytic shellfish toxin).

Rumors of southern pine deaths have been exaggerated

Researchers at the University of Georgia have a message for Southern tree farmers worried about unexplainable pine tree deaths: Don't panic.

Why the seahorse's tail is square

Why is the seahorse's tail square? An international team of researchers has found the answer and it could lead to building better robots and medical devices. In a nutshell, a tail made of square, overlapping segments makes for better armor than a cylindrical tail. It's also better at gripping and grasping. Researchers describe their findings in the July 3 issue of Science.

Donuts, coffee cups and soundproofing with quantum physics

Doughnuts, electric current and quantum physics - this will sound like a weird list of words to most people, but for Sebastian Huber it is a job description. ETH-professor Huber is a theoretical physicist who, for several years now, has focused his attention on so-called topological insulators, i.e., materials whose ability to conduct electric current originates in their topology.

What bee-killing mites can teach us about parasite evolution

An infestation of speck-sized Varroa destructor mites can wipe out an entire colony of honey bees in 2-3 years if left untreated. Pesticides help beekeepers rid their hives of these parasitic arthropods, which feed on the blood-like liquid inside of their hosts and lay their eggs on larvae, but mite populations become resistant to the chemicals over time.

Nanospiked bacteria are the brightest hard X-ray emitters

In a step that they say overturns traditional assumptions and practice, researchers at the Tata Institute of Fundamental Research, Mumbai and Institute for Plasma Research, Gandhi Nagar have fashioned bacteria to emit intense, hard x-ray radiation.

When one thinks of hard x-rays and bacteria it is usually that the bacteria are at the receiving end of the x-ray source - being imaged, irradiated for some modification or simply assessed for radiation damage. One hardly thinks of using bacteria as a source of x-rays, far from turning them into the brightest among such sources.

Creating a stopwatch for volcanic eruptions

We've long known that beneath the scenic landscapes of Yellowstone National Park sleeps a supervolcano with a giant chamber of hot, partly molten rock below it.

Though it hasn't risen from slumber in nearly 70,000 years, many wonder when Yellowstone volcano will awaken and erupt again. According to new research at Arizona State University, there may be a way to predict when that happens.

Friction reduction breakthrough is not snake oil

Snake skin inspired surfaces smash records, providing an astonishing 40% friction reduction in tests of high performance materials.

Pollution helps trees fight infection

Trees that can tolerate soil pollution are also better at defending themselves against pests and pathogens. "It looks like the very act of tolerating chemical pollution may give trees an advantage from biological invasion", says Dr Frederic E. Pitre of the University of Montreal and one of the researchers behind the discovery.

Unexpectedly, whilst studying the presence of genetic information (RNA) from fungi and bacteria in the trees, the researchers found evidence of a very large amount of RNA from a very common plant pest called the two-spotted spidermite.

Acidification stunts growth of developing pink salmon

Pink salmon that begin life in freshwater with high concentrations of carbon dioxide, which causes acidification, are smaller and may be less likely to survive, according to a new study.

The risks of ocean acidification on marine species have been studied extensively but the impact of freshwater acidification is not well understood. The study is one of the first to examine how rising carbon dioxide levels caused by climate change can impact freshwater fish.