i htink there is a BIG difference in saying a vegetable was "invented" and saying it was altered by man thre generations. all of these vegetables have been with us for a long long time but some of them were altered by men for various reasons, some of them for the better.
and yes, grass is a vegetable so are dandelion greens. and how you determine what is an "herb" vs. what is a vegetable i would really like to know. cayenne - vegetable or herb? burdock root - veg or herb? etc etc. etc. these artificial categories we have created do serve some purposes, but ultimately if it grows up from the ground and has healing nutrients in it, then its a good thing, be it veg fruit or herb.