Evolving doves...

In Christianity the dove is a symbol of love and peace, originating from the bird that Noah was supposed to have sent from the ark. Well, Chelmsford doves have never read the Bible, either that or the ones in this part of East Anglia have evolved into creatures far more aggressive and less loving than their forbears. Darwin used the example of the variation in appearance through selective breeding on pigeons as a proof of the viability of natural selection. It appears still to be in action.
 
A pair of grey collared doves in our garden regularly dive-bomb pigeons on our bird-feeders, driving them off. Not long ago I saw a pigeon and a significantly smaller dove face each other off on the grass. The pigeon twice lunged at the dove, which stood his ground; each time the pigeon lost his nerve. No blood was spilled. Today, one of the doves having evicted a pigeon from the feeder by the expedient of landing on top of him, refused to give way to a much larger magpie also looking for a meal.
 
Is this, I wonder, the ‘Essex’ effect working its way into previously mild-mannered birds? I understand from Wikipedia that the collared dove originates from the East, and has only been breeding in Britain since 1954, so Perfidious Albion influences natural selection even in doves. Where will it end? Will all those Renaissance pictures of the Holy Ghost depicted as a dove have to be redrawn?