In April, headlines proclaimed that the tiger population was finally showing signs of recovery; a new report from the World Wildlife Fund had found that numbers of the cats had grown from 3,200 in 2010 to 3,890 in the organization’s recent census. After a century of tiger numbers dropping due to poaching and habitat loss, […]

Gut microbes cause obesity by sending messages via the vagus nerve to pack on pounds, new research in rodents suggests. Bacteria in the intestines produce a molecule called acetate, which works through the brain and nervous system to make rats and mice fat, researchers report in the June 9 Nature. If the results hold up […]

Humans can’t easily protect themselves from the most dangerous species on Earth. The predator slips invisibly into homes, quietly stalks its prey and bites before a victim knows what happened. There’s little chance of escape. The attacker is Aedes aegypti, a mosquito that has, over time, developed a taste for people. It’s a city dweller […]

BOSTON — You’ve heard the advice: For clean hands, scrub with soap and water for as long as it takes to sing “Happy Birthday” twice. But is hand sanitizer just squirt and go? Finally, there’s a scientific answer: To kill bacteria, rub for at least 15 to 30 seconds. After 45 seconds, you’re not doing […]

Scientists have found a clue to why one type of DNA is passed down to children by their mothers — but not their fathers. DNA inside energy-producing organelles called mitochondria is destroyed in a dad’s sperm shortly after it fertilizes an egg, researchers report online June 23 in Science. A protein called CPS-6 cuts apart […]

At least one of comet 67P/Churyumov-Gerasimenko’s dusty outbursts was the result of a landslide. But such changes to the surface of the comet haven’t radically altered its appearance, suggesting it has had roughly the same look for decades — or longer. Images from the Rosetta spacecraft taken before its demise show what happened to the […]

Viruses in bats may have mixed and matched genes to create the virus that gave rise to the deadly SARS outbreak in 2003, a new study suggests. And it could happen again. All of the ingredients needed to create a new SARS virus are found among viruses currently infecting horseshoe bats, researchers report November 30 […]

ISO: A home for a stray space rock. Astronomers are tracking the motions of stars to figure out which one sent an alien asteroid speeding past Earth in October — but they may never find the rock’s true origins. Officially named ‘Oumuamua, the asteroid was spotted by the Pan-STARRS 1 telescope in Hawaii on October […]

The only fish known to hunt with wolf pack moves may not be true team players, just lemon-yellow me-firsts. Yellow saddle goatfish (Parupeneus cyclostomus) do more than school together as they dart over Indo-Pacific coral reefs. Like wolves, the goatfish take different roles in a pursuit. One or two fish may rush straight toward prey […]

Ceres may be regularly coughing up briny water or slush onto its surface. The discovery of waterlogged minerals and a growing ice wall suggests that the dwarf planet could harbor underground liquid water or slushy brine, which has escaped through cracks and craters in the recent past and may still be seeping out today. The […]