In the pine forests of Idaho, a bird called the South Hills crossbill is waging one seriously bizarre evolutionary war, says an article in the Wired .
For the last 5,000 years the crossbill has been coevolving with the lodgepole pine. The bird’s bills, which cross over each other instead of aligning, have been growing thicker to crack the pine nuts and steal seeds. In return, the pine’s cover has also been growing thicker.
While this is a normal evolutionary process, the weird bit is that the South Hills crossbill may have speciated without geographic isolation, which is problematic for traditional evolutionary theory, writes Matt Simon.