Blast in the Past
A supervolcanic eruption packs the punch of a small asteroid slamming into Earth. Some researchers hypothesize that these rare geologic cataclysms could throw up enough ash to affect climate and wipe out local populations. Scientists analyzing the remnants of a supervolcanic eruption that occurred 74,000 years ago in Toba, Indonesia—the largest in the past two million years—report in the July 6 Science that it did not drive away early humans. At a site in southern India, the team found ancient stone blades dating to before and after the Toba eruption. The blades show technological continuity, indicating that the locals survived the nearby release of 2,800 cubic kilometers of magma and 800 cubic kilometers of ash.
The biofuel called 2,5-dimethylfuran, or DMF—made by adding acids to glucose or fructose—packs 40 percent more energy than ethanol, bringing it on par with gasoline. And unlike ethanol, the compound does not become contaminated by absorbing water from the air. But getting rid of an intermediate compound that forms in the DMF reaction, called 5-hydroxymethylfurfural (HMF), has been troublesome—HMF reacts with the remaining sugars before the acid can. In the June 21 Nature, chemical engineers from the University of Wisconsin–Madison describe how the addition of liquid hydrocarbon quickly draws HMF to it. Hydrogen and another catalyst can then turn the HMF into DMF. Such catalytic reactions are simpler and more efficient than the fermentation methods used to make ethanol, although researchers need to evaluate the environmental effects of DMF.
Genetic analyses have revealed how felines have clawed their way around the world. The latest DNA study concludes that today’s 600 million house cats descended from five maternal lineages of a Near Eastern wildcat, Felis silvestris lybica, whose relatives today include the Scottish wildcat (photograph). The study, published online June 28 by Science Express, confirms that feline domestication took place in the Fertile Crescent, probably some 10,000 years ago, when humans began farming and most likely looked to cats to control grain-robbing rodents.