Researchers have pinpointed a gene that keeps important brain cells in mice from crossing their wires, providing a possible link between brain wiring and mood disorders like depression. Without the gene, called Pcdhαc2, mice acted more depressed, researchers report April 28 in Science. Nerve cells, or neurons, that produce the chemical messenger molecule serotonin extend […]

Fossils of a humanlike species with some puzzlingly ancient skeletal quirks are surprisingly young, its discoverers say. It now appears that this hominid, dubbed Homo naledi, inhabited southern Africa close to 300,000 years ago, around the dawn of Homo sapiens. H. naledi achieved worldwide acclaim in 2015 as a possibly pivotal player in the evolution […]

Face-to-face, a human and a chimpanzee are easy to tell apart. The two species share a common primate ancestor, but over millions of years, their characteristics have morphed into easily distinguishable features. Chimps developed prominent brow ridges, flat noses, low-crowned heads and protruding muzzles. Human noses jut from relatively flat faces under high-domed crowns. Those […]

Europe, not Africa, might have spawned the first members of the human evolutionary family around 7 million years ago, researchers say. Tooth characteristics of a chimpanzee-sized primate that once lived in southeastern Europe suggest that the primate, known as Graecopithecus, may have been a hominid, not an ape as many researchers assume. One tooth in […]

Jupiter’s scientific portrait is getting repainted. NASA’s Juno spacecraft swooped within about 5,000 kilometers of Jupiter’s cloud tops on August 27, 2016, giving scientists their first intimate look at the gas giant. The data are revealing surprising details about Jupiter’s gravity, powerful magnetic field and ammonia-rich weather system. The findings, which appear in two studies […]

With the discovery of sulfa drugs and antibiotics came man’s confidence in his ability to control infectious diseases. But now, that confidence is being shaken by once defenseless germs that have learned to outwit man and thrive in the face of his wonder drugs.… One way to cut down on drug resistance transfer is to […]

Mutations that prevent cells from spell-checking their DNA may make cancer cells vulnerable to immunotherapies, a new study suggests. A type of immune therapy known as PD-1 blockade controlled cancer in 77 percent of patients with defects in DNA mismatch repair — the system cells use to spell-check and fix errors in DNA (SN Online: […]

When things get hot, embryonic bearded dragon lizards turn female — and now scientists might know why. New analyses, reported online June 14 in Science Advances, reveal that temperature-induced changes in RNA’s protein-making instructions might set off this sex switch. The findings might also apply to other reptile species whose sex is influenced by temperature. […]

Earth’s dry regions have more trees than once thought — a hopeful note in the fight against climate change. An analysis of high-resolution satellite imagery reveals that drylands globally have 40 to 47 percent more tree cover (an extra 467 million hectares) than reported in earlier estimates. An international team of researchers used Google Earth […]

John Archibald Wheeler was fond of clever phrases. He made the term “black hole” famous in the 1960s. He also coined the now-familiar “wormhole” and “quantum foam.” While further pondering the mystery of quantum physics at the University of Texas at Austin during the 1980s, Wheeler repeatedly uttered his favorite interrogative slogan: “How come the […]