How does gradual evolutionary change come up with a complex trait such as flying? One possible intermediate state for insects is surface-skimming, in which the insect's weight is borne by water, meaning that the wings must deal only with generating forward motion. A limited analysis suggested, however, that present-day surface skimmers were evolutionary latecomers, and had lost their previous ability to fly. In the November 21
A US Army facility may have inadvertently sent live anthrax spores to government and commercial labs in nine states, and to one US Air Force base abroad, according to the Centers for Disease Control and Prevention.