The Great French Grape Blight, was another interesting example of mono-culture and hybrid life.  When American vines were introduced to Europe, they brought a terrible disease that french vines were not immune to.  This killed about 40% of the French grape vines.  A solution was found to combine the American plants and the French plants through a process called grafting.

From Wikipedia’s Article:

After Charles Valentine Riley confirmed Planchon’s theory, Leo Laliman and Gaston Bazille, two French wine growers, both suggested the possibility that if vinifera vines could be combined, by means of grafting, with the aphid-resistant American vines, then the problem might be solved.