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
Members of a previously uncontacted Venezuelan tribe have the most diverse microbiomes yet described.