Earth
We summarize the week's scientific breakthroughs every Thursday.
- Climate
Ancient Norse colonies hit bad climate times
Temperatures in Iceland plummeted soon after settlers arrived, a new chemical analysis suggests.
- Earth
Green-ish pesticides bee-devil honey makers
Pesticides are agents designed to rid targeted portions of the human environment of undesirable critters – such as boll weevils, roaches or carpenter ants. They’re not supposed to harm beneficials. Like bees. Yet a new study from China finds that two widely used pyrethroid pesticides – chemicals that are rather “green” as bug killers go – can significantly impair the pollinators’ reproduction.
- Earth
Country ants make it big in the city
Odorous house ants act like invading aliens when they discover urban living.
- Life
Mature females key to beluga sturgeon survival
Hatchery fish are unlikely to restore caviar-producing fish populations, a new assessment finds.
- Earth
Fowl surprise! Methylmercury improves hatching rate
A pinch of methylmercury is just ducky for mallard reproduction, according to a new federal study. The findings are counterintuitive, since methylmercury is ordinarily a potent neurotoxic pollutant.
- Space
Geophysicists push age of Earth’s magnetic field back 250 million years
South African rocks suggest that the earliest stages of life on Earth were protected from harmful solar radiation.
- Earth
Arctic seafloor a big source of methane
Measurements show that Arctic undersea methane deposits, previously thought to be sealed by permafrost, are leaking into the atmosphere.
- Earth
Earth knocked for a loop
Chile’s February 27 temblor, tectonically linked to another giant quake 50 years ago, sped up the Earth’s rotation and tipped the planet’s axis.
- Chemistry
Plasticizers kept from leaching out
‘Chemicals of concern’ may be made safer in new materials.
- Agriculture
Frogs: Clues to how weed killer may feminize males
Atrazine, a widely used agricultural herbicide, not only can alter hormone levels in the developing frogs, but also perturb their physical development — and lead to an excess number of females, researchers report. Their new findings may help explain observations reported by a number of other research groups that at least in frogs, fairly low concentrations of atrazine can induce a feminization — or demasculinization.
- Paleontology
Ancient DNA suggests polar bears evolved recently
A study of a rare Norwegian fossil narrows down when polar bears evolved and finds they are closely related to modern-day brown bears in Alaska.
- Earth
Frogs: Weed killer creates real Mr. Moms
Several months back, a Berkeley undergraduate began witnessing distinctly odd behavior in frogs she was caring for in the lab. At about 18-months old, some frisky guys began regularly mounting tank mates, as if to copulate. Except that their chosen partner was invariably male. He had to be. Because genetically, every animal in the tank was male.
