Science, October 2
It’s not every day that scientists make an announcement that reshapes our theories of how modern humans came to be–and indeed, the research published in Science was 17 years in the making. Back in 1992, anthropologists unearthed fossilized hominid remains in Ethiopia, eventually finding bone fragments from 35 individuals, including a partial skeleton from a female they nicknamed Ardi. The new species, named Ardipithecus ramidus, lived 4.4 million years ago, and it brings us closer than ever before to the ancestral species that gave rise to both humans and apes. Researchers were surprised, however, to find that Ardi bore little resemblance to chimps, our closest living primate relatives.
Proceedings of the National Academy of Sciences, September 29
The world may still be in the grip of a global recession, but that may not be entirely a bad thing: Researchers found that when the economy takes a turn for the worse, public health actually improves. Mortality rates fell during the Great Depression, the study found, possibly because people couldn’t afford to smoke and drink as much, and because the unemployed have more time to sleep and less chance of dying in industrial or traffic accidents. In some lighter and bubblier news, another study probed the enduring mystery of why champagne bubbles are so essential. They don’t just provide a fizzy feeling on the tongue, researchers found–they also carry aromatic chemical compounds up through the liquid and release them into the air above the glass. The subtle fragrance enhances the overall flavor, scientists said as they happily waved their glasses for a refill.
PLoS ONE, September 30
This study got wide attention in large part because it dealt with a celebrity dinosaur: Sue, the Tyrannosaurus rex on exhibit in Chicago’s Field Museum. Paleontologists re-examined the round holes in the dinosaur’s mandible that had previously been considered bite marks, and argued that the holes were actually caused by a lowly parasite commonly found in pigeons. The researchers argue that the throat infection first formed lesions and then wore the bone away in spots. The resulting inflammation choked off the dino’s esophagus, they say, eventually killing the mighty beast. It’s an interesting story, but the researchers haven’t convinced everyone.
Proceedings of the Royal Society B, September 30
Oddly enough, the next study also involves a controversy over the cause of death of a long-deceased somebody–this time, an Egyptian noblewoman named Irtyersenu who was mummified around 600 BC. In 1825, Irtyersenu became the subject of the first scientific autopsy of a mummy. The doctor found an ovarian tumor (the mummy was preserved with its organs intact) and pronounced it the cause of death, but the new study refutes that claim. The tumor was benign, researchers say, and it was actually tuberculosis that did in Irtyersenu.
Nature, September 29
A study on earthquakes was eerily well timed, as it immediately followed a tsunami-triggering quake in the South Pacific, and an even more destructive quake in Indonesia. The researchers looked back over the well-kept seismic records from the San Andreas fault in California, and found evidence that the 9.3 magnitude Sumatra earthquake of 2004 weakened the San Andreas fault thousands of miles away, making it more prone to tremors. The researchers hope that the work could one day help experts predict earthquakes, but for now, it’s just a hope.