Science briefs: Why mushrooms glow at night

The existence of bioluminescent mushrooms has been noted since the time of the ancient Greeks, but less is known about why a small percentage of fungi would feel the need to glow like fireflies.

At least until now.

In research published in the journal Current Biology, scientists said it's likely that the mushrooms are attempting to attract beetles, flies, wasps and other insects to help spread fungal spores.

"It appears that fungi make light so they are noticed by insects who can help the fungus colonize new habitats," said senior author Jay Dunlap, a biologist at Dartmouth's Geisel School of Medicine.

Federal records show that this winter and the first two months of 2015 were the hottest on record globally, with a chilly U.S. East sticking out like a cold thumb in a toastier world.

At nearly 1.5 degrees Fahrenheit above the 20th century average, last month was the second warmest February on record globally, slightly behind 1998. But the combined January and February temperature beat the old record for the first two months set in 2002. December through February broke the meteorological winter record set in 2007.

The latest evolutionary psychology suggests that hetero- sexual men might be on the lookout for a very specific kind of spine curve in sexual partners. And that could be because women with that specific spine curve were more likely to give birth successfully, making them more attractive as partners.

The researchers examined the way the female spine attaches to the buttocks (a feature called "vertebral wedging") in hopes of proving that a curve of 45.5 degrees between the two is objectively more attractive than smaller or larger angles — because that curve helps women get through pregnancy. This bend in the female spine lets them shift the increased weight in front of them during pregnancy back over their whole pelvis, which keeps their hips from being strained by the shift in their center of mass.

So if the idea of biological beauty has any weight, men would have evolved to find women with the best spinal curve to support pregnancy most attractive. Sure enough, men rated the images as more attractive the closer they got to that ideal curve.

The world could suffer a 40 percent shortfall in water in just 15 years unless countries change their use of the resource, a U.N. report warned.

Many underground water reserves are already running low, while rainfall patterns are predicted to become more erratic with climate change. As the world's population grows to an expected 9 billion by 2050, more groundwater will be needed for farming, industry and personal consumption.

The report predicts global water demand will increase 55 percent by 2050, while reserves dwindle. If current usage trends don't change, the world will have only 60 percent of the water it needs in 2030, it said. Having less available water risks catastrophe on many fronts: Crops could fail, ecosystems could break down, industries could collapse, disease and poverty could worsen and conflicts over access to water could become more frequent.