Unexpected pattern of evolution found across hemispheres
The most ambitious effort yet to trace the evolutionary history and geography of living birds is ruffling the feathers of some old ideas.
For the first time, the new avian family tree places each of the 9,993 known species of living birds on its own twig. Such a broad view allows biologists to look for patterns of sluggish or exuberant formation of new species, a critical part of understanding nature’s quirky patterns of diversity. In the new tree, Western Hemisphere birds seem to have diversified faster than Eastern Hemisphere ones, Walter Jetz of Yale University and his colleagues report in an upcoming Nature.