Sheesh, and I thought I often post off topics...
It looks like both sides of the debate are a bit off. You can't compare Muslims of 10-11c Caliphate and today's hoards streaming into Europe any more than you can equate recently Christina Meroving or Carolinian crowd with their modern co-religionists. Have to compare apples to apples. Besides, contrary to popular modern, especially American, beliefs - history and human development is cyclical not linear and a developed culture often reverts back to it's less developed state. It happened time and time again. And so we can't really look at today's state of any given culture and ascribe to it the same state 1000 years ago. And vice versa.
BTW back to the original topic.
Why no one is talking about this?
"The sweet potato or kumara (Ipomoea batatas) is a dicotyledonous plant that belongs to the family
Its large, starchy, sweet-tasting, tuberous roots are a root vegetable. The young leaves and shoots are sometimes eaten as greens. Ipomoea batatas is native to the tropical regions in the Americas
, the Quechua name for a type of sweet potato is kumar, strikingly similar to the Polynesian name kumara and its regional Oceanic cognates (kumala, umala, 'uala, etc.), which has led some scholars to suspect an instance of Pre-Columbian trans-oceanic contact.
In New Zealand
, the most common variety is the Red (purple) cultivar, and is called kumara, a name derived from the Māori name kūmara..."