I tend to think of evolution of a species as an event of thousands of years. A recent study suggests that blackcaps, a Central European warbler have shown evolutionary changes over the last 50 years, possibly because of people feeding birds!
Traditionally their summer migration has been to Spain, but some blackcaps have been lured to bird feeders in Britain where they breed with others and over winter there. Now German researchers are observing significant anatomical differences between the two populations. Their British cousins wings are rounder and they have longer narrower beaks--"the better to eat from bird feeders" my dear!
Is this evolution-by-human a problem? The experts feel not, for the British variety no longer have to make the long migration twice a year. But now for the big question. Do they sing with an accent? That remains to be determined, old chap.
For the whole story and pictures go to Treehugger.com