@mibbelucieachwell well, quite so. I mean, if we're looking that far back we can deport 95% of the current population of the British Isles on the grounds of being 'not native', and probably north of 80% of plant and animal species which we depend on for food.
And let's face it, that man wouldn't recognise a Soay if it jumped a 5 ft fence right in front of him. (I used to live on a farm that had Soays, they are hilarious).