Used to live in town and had a backyard garden.  Several times during the year the wife would bring home a watermellon and the kids would eat it on the deck.  I am sure many seeds were spint into the garden.  Years later a plant can up and I let if grow.  It producted a delicious mellon that was orange on the inside.  We had never seen an orange watermellon, so whatever went into the soil a prior year had to be a hybrid seed that went back to an older branch on its family  tree.
You don't always reap what you sew.